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Everything you need to know about Computed Tomography (CT) & CT Scanning

September 2021 Imaging Pearls - Educational Tools | CT Scanning | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ September 2021

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Adrenal

  • “Pheochromocytomas are neoplasms of the chromaffin cells of the adrenal medulla in 80%–90% of cases. Ectopic/extra-adrenal pheochromocytomas that arise from sympathetic and para-aortic sympathetic ganglia are called paragangliomas. Pheochromocytomas and paragangliomas occur in 0.05%–0.1% of hypertensive patients, and their combined annual incidence in the United States is estimated to be between 500 and 1,600 cases. Approximately 10%–15% of pheochromocytomas and paragangliomas are malignant, but it could be up to 40%. Pheochromocytomas release catecholamines (epinephrine and norepinephrine) and their metabolites metanephrine and normetanephrine, resulting in hypertension, arrhythmia, and/or hyperglycemia. About 40% of paragangliomas secrete catecholamines. Head and neck paragangliomas only secrete catecholamines about 5% of the time and often it is dopamine.”  
    Neuroendocrine and Adrenal Tumors, Version 2.2021  
    Manisha H. Shah et al.
    J Natl Compr Canc Netw 2021;19(7):839–868 
  • "The peak incidence of occurrence for pheochromocytomas is between the third and fifth decades of life, but they generally occur at a younger age and are more likely to be bilateral in patients with familial disease. Paragangliomas are more likely to be malignant than pheochromocytomas in the adrenal medulla (about 40% vs 10%). Pheochromocytomas and paragangliomas associated with a familial syndrome tend to be more aggressive and more likely to metastasize than sporadic tumors. In fact, a study showed that 87.5% of patients presenting with these tumors prior to age 20 harbored a germline mutation in one of several genes tested if they also had metastatic disease. For those without metastases, the rate of identification of these mutations was still high, at 64.7%.”
    Neuroendocrine and Adrenal Tumors, Version 2.2021  
    Manisha H. Shah et al.
    J Natl Compr Canc Netw 2021;19(7):839–868 
  • “Adrenocortical carcinomas are rare (incidence, 0.7–2 per million). ACC has a bimodal age distribution, with peak incidences in early childhood and the fourth to fifth decades of life. Women are more frequently affected (55%–60%). Most cases are sporadic; however, ACCs have been observed in association with several hereditary syndromes, including Li-Fraumeni syndrome, Lynch syndrome, Beckwith-Wiedemann syndrome, MEN1, and familial adenomatous polyposis. The underlying mechanisms of carcinogenesis in sporadic ACCs have not been fully elucidated; however, inactivating somatic mutations of the p53 tumor suppressor gene  (chromosome 17p1381) and alterations at the 11p15 locus (site of the IGF2 gene) seem to occur frequently.”  
    Neuroendocrine and Adrenal Tumors, Version 2.2021  
    Manisha H. Shah et al.
    J Natl Compr Canc Netw 2021;19(7):839–868 
  • "Approximately 60% of patients present with evidence  of adrenal steroid hormone excess, with or without virilization. Signs and symptoms associated with hypersecretion of cortisol, called Cushing syndrome, include weight gain, weakness (primarily in proximal muscles), hypertension, psychiatric disturbances, hirsutism, centripetal obesity, purple striae, dorsocervical fat pad and supraclavicular fat pad enlargement, hyperglycemia, and hypokalemia. Aldosterone-secreting tumors may present with hypertension, weakness, and hypokalemia. Androgen-secreting tumors in women may induce hirsutism, virilization, deepening of the voice, and oligo/amenorrhea. In men, estrogen-secreting tumors may induce gynecomastia and testicular atrophy. Hormonally inactive ACCs typically produce symptoms related to tumor burden, including abdominal pain, back pain, early satiety, and weight loss.”
    Neuroendocrine and Adrenal Tumors, Version 2.2021  
    Manisha H. Shah et al.
    J Natl Compr Canc Netw 2021;19(7):839–868 

  • Neuroendocrine and Adrenal Tumors, Version 2.2021  
    Manisha H. Shah et al.
    J Natl Compr Canc Netw 2021;19(7):839–868 

  • Neuroendocrine and Adrenal Tumors, Version 2.2021  
    Manisha H. Shah et al.
    J Natl Compr Canc Netw 2021;19(7):839–868 
Chest

  • Interruption of the inferior vena cava: facts
    - Interruption of the inferior vena cava (IVC) with azygos continuation is a rare congenital anomaly, in which the IVC is interrupted below the hepatic vein and venous return beyond this point is restored by the dilated azygos and hemiazygos veins draining into the superior vena cava.
    - this congenital anomaly could be isolated, but often it is part of more complex syndrome including for example cardiac malformations, asplenia, and polysplenia syndrome. Interruption of the IVC with azygos continuation is the second most common abnormality associated with polysplenia syndrome 
  • “The polysplenic syndrome is defined by the presence of multiple spleens, usually numbering between two and six. In contrast to accessory spleens, the spleens are of uniform size. Accessory spleens usually measure between 1 and 2 cm and are not considered as a form of the polysplenic syndrome. Splenosis, an acquired rather than congenital condition that arises in the context of traumatic splenic rupture, can be ruled out by patient history.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396,
  • "Splenosis typically consists of multiple small implants of splenic tissue; it can mimic peritoneal carcinomatosis or endometriosis depending on the clinical context.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396,
  • "The syndrome of polysplenia is often accompanied by a variable spectrum of visceral and vascular developmental anomalies. It is rarely diagnosed in adults. While it is estimated that 2.5/100,000 infants are born with this anomally, fewer than 5% are still alive at five years of age due to the associated severe cardiac anomalies.The syndrome is associated with multiple congenital malformations that may involve the solid organs and digestive tube of the abdominal cavity, the heart, or the great vessels. The diagnosis is often made during surgical exploration for an associated cardiac or digestive anomaly. Among the most common vascular anomalies are agenesis of the suprarenal inferior vena cava with persistent continuity of the azygos vein, and pre-duodenal position of the portal vein. Biliary atresia is found in nearly 50% of cases, common mesentery in more than 75% of cases, and an abbreviated or annular pancreas in 85–90% of cases.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396
  • “Anomalies include asplenia, the congenital absence of the spleen. This can be isolated or part of a clinical sequela of a broader syndrome such as Ivermark syndrome, a heterotaxy syndrome occurring in 1 in 10,000 to 40,000 cases. CT will show lack of spleen and Tc-99 red blood cell scan will show lack of uptake.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • “IPH is a diagnosis of exclusion and can be considered after underlying diseases resulting in alveolar haemorrhage, including Goodpasture’s syndrome, granulomatosis with polyangiitis, systemic lupus erythematosus, rheumatoid arthritis, coagulation disorders, pulmonary infections, neoplasms, additional disorders such as pulmonary venoocclusive disease and pulmonary capillary haemangiomatosis, and toxins such as cocaine, pesticides, and insecticides, have been excluded.”
    Idiopathic pulmonary haemosiderosis: spectrum of thoracic imaging findings in the adult patient  
    L. Khorashadi et al.
    Clinical Radiology 70 (2015) 459-465
  • “IPH classically presents as a triad of haemoptysis, iron-deficiency anaemia, and opacities on thoracic imaging (representing pulmonary haemorrhage), and is considered a diagnosis of exclusion. For children with IPH, the disease course is severe and the prognosis is poor. However, adults generally have a longer disease course with milder symptoms and the prognosis is more favourable. However, this condition can progress to pulmonary fibrosis, resulting in respiratory failure and cor pulmonale.”
    Idiopathic pulmonary haemosiderosis: spectrum of thoracic imaging findings in the adult patient  
    L. Khorashadi et al.
    Clinical Radiology 70 (2015) 459-465
  • “HRCT optimally demonstrates thickening of the interstitium, intralobular lines, and associated findings such as traction bronchiectasis and bronchiolectasis. Honeycomb cysts may be present and are typically identified in the peripheral and basilar regions. Progressive massive fibrosis (PMF), classically described as a complication of silicosis or other. pneumoconiosis, may rarely develop in IPH and is typified by dense mass-like consolidation in the upper and mid-lung zones, architectural distortion, and regions of high attenuation corresponding to iron deposition.”
    Idiopathic pulmonary haemosiderosis: spectrum of thoracic imaging findings in the adult patient  
    L. Khorashadi et al.
    Clinical Radiology 70 (2015) 459-465
  • “Progressive massive fibrosis (PMF), classically described as a complication of silicosis or other. pneumoconiosis, may rarely develop in IPH and is typified by dense mass-like consolidation in the upper and mid-lung zones, architectural distortion, and regions of high attenuation corresponding to iron deposition.”
    Idiopathic pulmonary haemosiderosis: spectrum of thoracic imaging findings in the adult patient  
    L. Khorashadi et al.
    Clinical Radiology 70 (2015) 459-465
  • “The clinical course consists of two distinct phases, an acute phase and a chronic phase, during which certain clinical symptoms and imaging features may be present. The acute phase is characterized by ground-glass opacity and consolidation due to alveolar haemorrhage. In the chronic phase, the radiological picture is dominated by features of pulmonary fibrosis and honeycombing. Although imaging features are often non-specific, identification and understanding of the abnormalities that may be present on thoracic imaging examinations is important to guide appropriate clinical management.”
    Idiopathic pulmonary haemosiderosis: spectrum of thoracic imaging findings in the adult patient  
    L. Khorashadi et al.
    Clinical Radiology 70 (2015) 459-465
  • “Large-airway pathological conditions are a heterogeneous group of diseases that include focal and diffuse lesions. Although tracheobronchial neoplasms are uncommon, there is a high incidence of malignancy. Furthermore, most of the benign neoplasms and inflammatory conditions are usually symptomatic and need treatment. Focal lesions may be subdivided into benign neoplasms (papilloma, hamartoma, and carcinoid), malignant neoplasms (squamous cell carcinoma, adenoid cystic carcinoma, other primary neoplasms such as lymphoma or haemangiopericytoma, and secondary malignancy), and non-neoplastic conditions (tuberculosis, post-intubation stenosis, idiopathic subglottic stenosis, post-inflammatory pseudotumour, trauma, and foreign body).”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • "Diffuse lesions can be classified into lesions with dilatation of the tracheobronchial lumen (Mounier- Kuhn syndrome and acquired tracheobronchomegaly), lesions with stenosis (rhinoscleromatosis, granulomatous bronchitis, amyloidosis, sarcoidosis, granulomatosis with polyangitis, relapsing polychondritis, osteochondroplastic tracheobronchopathy), and lesions with respiratory collapse (tracheobronchomalacia).”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • "Adenoid cystic carcinoma This is the second most common tracheal malignancy after squamous cell carcinoma, and it is the most common tumour of salivary glands in the large airways. This tumour has no relation with smoking. The patients are generally younger than 40 years of age, and there is no difference in gender distribution.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.
    Insights Imaging (2017) 8:255–270 
  • "Adenoid cystic carcinoma arises most frequently in the lower trachea and main bronchi and has predominantly submucosal extension, appearing as a lesion with a smooth contour and intact mucosa at direct bronchoscopy. CT shows a smooth mass with endoluminal and extraluminal growth, and soft tissue attenuation, which usually involves more than 180 degrees of the airway circumference and often encircles the lumen.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • “Congenital tracheobronchomegaly is defined as significant dilation of the large airway, affecting the trachea and bronchi up to the fourth branch, secondary to severe atrophy of the longitudinal elastic fibres and thinning of the muscularis mucosa of the affected segments. Typically, the diagnosis is made in males between 20 and 40 years of age with a history of recurrent pulmonary infections. Although most of the cases are sporadic, a familial susceptibility exists, and the syndrome has been associated with connective-tissue diseases, such as Ehlers-Danlos in adults or cutis laxa in children.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • "CT shows diffuse and symmetrical dilatation of the large airway, generally a tracheal diameter greater than 3 cm and main bronchi diameter greater than 2.4 cm, associated with central bronchiectasis. Expiratory collapse is common, and the presence of tracheal diverticula gives the trachea a corrugated appearance.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • "Rhinoscleroma is a chronic, slowly progressive inflammatory disease of the upper respiratory tract, secondary to Klebsiella rhinoscleromatis infection. Rhinoscleroma is found predominantly in rural areas with poor socioeconomic conditions, where infection is facilitated by crowding and poor hygiene and malnutrition.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • "Relapsing polychondritis is a systemic disease, characterised by recurrent episodes of cartilaginous inflammation that lead to cartilage destruction. The disease is characterised by a chondral and perichondral inflammation secondary to an immune-mediated reaction of unknown cause, which implies antibodies against extracellular matrix components such as collagen type II and matrilin 1. At the time of diagnosis, the respiratory tract involves only 10% of the patients, but in the course of the disease it occurs in up to 50%. Although the disease affects men and women equally, the airway affectation is more common in women. Involvement of the respiratory tract carries a poor prognosis, and mortality is usually secondary to pneumonia.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • "CT shows increased attenuation and thickening of the tracheobronchial wall, with or without mural calcifications, and sparing of the posterior membranous wall. At a later stage, fibrosis leads to luminal irregular narrowing, and loss of the structural support of the cartilage leads to tracheobronchomalacia, which is seen as tracheobronchial collapse and air trapping on the expiratory CT scan.”
    Central airway pathology: clinic features, CT findings with pathologic and virtual endoscopy correlation  
    Daniel Barnes et al.  
    Insights Imaging (2017) 8:255–270 
  • Focal Lesions: Benign Neoplasms
    - Papilloma 
    - Hamartoma 
    - Carcinoid 
  • Focal Lesions: Malignant Neoplasms
    - Squamous cell carcinoma (SCC) 
    - Adenoid cystic carcinoma 
    - Haemangiopericytoma 
    - Lymphoma 
    - Metastases
  • Focal Lesions: Non-neoplastic lesions
    - Tracheobronchial tuberculosis 
    - Post-intubation stenosis 
    - Idiopathic tracheal stenosis 
    - Inflammatory pseudotumour 
    - Foreign body aspiration 
    - Tracheobronchial trauma 
  • Diffuse lesions: Non-neoplastic lesions
    - Mounier-Kuhn syndrome 
    - Acquired tracheobronchomegaly 
    - Rhinoscleromatosis 
    - Amyloidosis 
    - Granulomatosis with polyangitis 
    - Sarcoidosis 
    - Relapsing polychondritis 
    - Tracheobronchopathia osteochondroplastica
    - Tracheobronchomalacia 
  • Trachea Filling Defect-Differential Dx
    - Primary/Secondary
    - True/Pseudo
    - Benign or malignant
    - Single/Multiple
  • Trachea Filling Defect-Differential Dx
    - Pseudotumor, foreign body, web
    - Primary malignancy-squamous, adenoid cystic
    - Primary Benign-Hemangioma, papilloma, chondroma, fibrovascular Polyp
    - Direct invasion-bronchogenic, esophagus, thryoid
    - Multiple –Metastasis/Laryngotracheal papillomatosis
  • Diffuse Narrowing of the Trachea or Main Bronchi
    - Relapsing polychondritis
    - Amyloidosis
    - Sarcoidosis
    - Wegener’s granulomatosis
    - Tracheopathia osteochondroplastica
    - Carcinoma
    - Infection (TB, histoplasmosis, coccidiomycosis)
  • Wegener Granulomatosis: Facts 
    - Necrotizing vasculitis that involves small to medium vessels
    - May involve ear, nose, throat, lung or kidneys
    - Clinical presentation ranges from sinusitis to cough, fever, wheezing to hematuria
  • Wegener Granulomatosis: Facts
    - Upper airways involved in up to 92% of cases, renal in 80% and joints in 67%
    - Age at dx usually 40-55 yrs
    - M=F but females have airway problems more commonly
    - Treatment with steroids and cyclophosphamide
  • Wegener Granulomatosis: Chest
    - Cavitary nodules
    - Large airway stenosis
    - Nodules 1-10 cm in size
    - Consolidation with or w/o hemorrhage
    - Subglottic stenosis
    - Adenopathy uncommon
  • MDCT of the Airways
    - Narrowing of the Airway
    -- Tumor
    -- Infection
    -- Trauma
    -- Extrinsic Compression by normal structure (enlarged thyroid gland or vascular anomaly)
  • Nonneoplastic Lesions of the Trachea: Diffuse Disease
    - Wegener granulomatosis
    - Relapsing polychondritis
    - Tracheobronchopathia osteochondroplastica
    - Amyloidosis
    - Papillomatosis
    - Rhinoscleroma
  • Tracheal Papillomatosis: Facts
    - More common in children
    - Occurs in 5% of patients with laryngeal papillomatosis
    - May be single or multiple
    - Airway obstruction may lead to atelectasis, air trapping, postobstructive infection or bronchiectasis
  • Tracheopathia Osteochondroplastica: Facts
    - TPO is an uncommon, benign, but slowly progressive disease of unknown etiology. It is characterized by endoluminal projection of cartilaginous and bony nodules arising in the submucosa of the trachea. Involvement may extend to lobar or segmental bronchi. TPO should be considered in cases where cough, dyspnea, persistent pulmonary infection, hoarseness, or recurrent hemoptysis remain after appropriate treatment of other presumptive underlying causes.
  • Pulmonary Sling: Facts
    - Left pulmonary aa arises from the right pulmonary aa and passes between the trachea and esophagus
    - Tracheobronchiomalacia and/or stenosis can occur in up to 50% of cases
  • Diffuse Narrowing of the Trachea or Main Bronchi
    - Relapsing polychondritis
    - Amyloidosis
    - Sarcoidosis
    - Wegener’s granulomatosis
    - Tracheopathia osteochondroplastica
    - Carcinoma
    - Infection (TB, histoplasmosis, coccidiomycosis)
  • Nonneoplastic Lesions of the Trachea: Focal Disease
    - Postintubation stenosis
    - Postinfectious stenosis
    - Posttransplantation stenosis
    - Systemic diseases that involve the airway
    -- Crohn disease
    -- Sarcoidosis
    -- Behcet syndrome
  • Nonneoplastic Lesions of the Trachea: Diffuse Disease
    - Wegener granulomatosis
    - Relapsing polychondritis
    - Tracheobronchopathia osteochondroplastica
    - Amyloidosis
    - Papillomatosis
    - rhinoscleroma
  • Tracheal Papillomatosis: Facts
    - Drop lesions may cavitate
    - Laser treatment common but lesions often recur
    - Malignant degeneration to squammous cell carcinoma occurs in up to 10% of adult cases
  • Rhinoscleroma
    - Rhinoscleroma (RS) is a chronic, slowly progressive granulomatous infection of the upper airways caused by Klebsiella sp: first described by Von Hebra - 1870
    - Endemic in tropical/subtropical areas with > 80% reported 5 endemic foci: Mexico, South and Central America; Africa (5%), Indonesia; Eastern Europe
    - Infection via person to person transmission; typically affects lower socioeconimic groups, esp. rural communities
    - Sporadic occurrence in US:  6 cases in 1993
  • Rhinoscleroma
    - RS usually affects pts 20-30 yrs old; > women
    - Prediliction for the nasal cavity (> 95%); pharynx 18-43%; trachea – 12%; bronchi 5%
    - Stage 1: catarrhal phase – purulent inflammation
    - Stage 2: atrophic stage – crusting leading to friable membranes prone to bleed
    - Stage 3: granulomatous phase – with proliferating nodules and masses
    - Stage 4: sclerosing phase
  • Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important.
    Main body: Blunt thoracic aortic injury may be fatal if not diagnosed and treated expeditiously. Endovascular options allow safe and effective management of these dangerous injuries. This paper describes the overview of blunt thoracic aortic trauma, the epidemiology, presentation, diagnosis, and treatment options with a focus on endovascular management.  
    Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.  
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62 
  • Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important. and treatment options with a focus on endovascular management.  
    Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.  
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62 
  • “Up to 80% of patients presenting with blunt thoracic aortic injury(BTAI) die before hospitalization, and in the remaining survivors, in- hospital mortality is as high as 46%. While this is a potentially lethal injury, it is rare and accounts for 1.5% of thoracic trauma.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Rapid deceleration is the universal mechanism of this injury. Most commonly, there are multiple other life- threatening injuries present with less than 20% having this as an isolated injury making the diagnosis and initial next steps challenging. BTAI is defined as a tear in the aorta that is a result of a combination of shear and stretch forces, rapid deceleration, increased intravascular pressure and compression of the aorta between the anterior chest wall and vertebrae.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Injury can occur along the entire length of the aorta, essentially from the ascending aorta to the iliac bifurcation, although the injury typically occurs areas of aortic tethering, notably the aortic isthmus.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “Blunt thoracic aortic trauma is associated with other major entities of chest trauma, including, but not limited to, sternal fracture, 1st/2nd rib fractures, clavicle and/or scapular fractures, pneumothoraces, hemothoraces, flail chest, pulmonary contusions, diaphragm injury, tracheobronchial disruption and esophageal injuries; these should raise suspicion for BTAI.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Injuries are assigned one of 4 grades based on CTA imaging: grade 1 (intimal tear), grade II (intramural hematoma), grade III (pseudoaneurysm) and grade IV (rupture). Currently, the recommendation is to proceed with surgical repair of Grade II-IV injuries [20]. For grade I injuries, it is well established that no intervention is necessary as these tend to resolve on their own with conservative management. Grade II injures do fall into a “gray zone” between medical management and operative intervention although more recent studies do document that nonoperative is safe with close follow up.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular approaches have slowly replaced open surgical repair for the management of this pathology. Clearly, such patients that present with blunt thoracic injury should be relegated to centers that specialize in the polytrauma patient as it is their concurrent injuries that are the focus of their critical care.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “The CT findings of TAI can be divided into direct signs of injury and indirect or associated findings. Direct findings of aortic injury include intramural hematoma, intimal flap and pseudoaneurysm. Injuries that only involve the intima, classified as minimal aortic injuries, should only have direct findings of TAI. Minimal aortic injuries can present with an intimal flap, intraluminal aortic thrombus or intramural hematoma. With the improvement in technology allowing thinner CT slice thickness minimal aortic injuries are being diagnosed more frequently.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "Ductal remnants, a diverticulum or small bump, are normal remnants of the embryologic ductus arteriosus. This normal variant can simulate injury and can be very perplexing for the inexperienced or unaware radiologist. The ductal diverticulum is a remnant of the closed or partially closed ductus arteriosus which connects the pulmonary artery to the aorta in fetal circulation. Ductal remnants are located at the inferior surface of the aortic arch near the aortic isthmus which leads to their confusion with TAIs. Ductal remnants are typically smooth walled and have obtuse margins that are continuous with the aortic wall and are often calcified. The presence of calcification can be very helpful in distinguishing a ductal remnant from a TAI with the presence of calcification favoring a benign ductal remnant.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "Mediastinal hematomas can be due to injury to other structures including the pulmonary artery, great vessels or mediastinal veins, or even fractures of vertebral bodies. Presence of a mediastinal hematoma should prompt a careful search for an aortic, pulmonary artery or great vessel injury. In the absence of an identified arterial injury the hematoma is likely venous. A preserved fat plane around the aorta or hematoma centered away from the aorta is less likely to be associated with aortic injury and more likely to be venous.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "The best way to distinguish a true aortic root injury from motion artifact is to repeat thoracic imaging with ECG gating; and echocardiography can be a reasonable alternative. The difference between a study done without and with ECG gating is illustrated in. In our institution all of the chest CT done as part of a trauma survey are acquired without ECG gating. Since the majority of TAIs are at the aortic isthmus, which is typically well seen on non-gated studies, we feel the additional radiation exposure and time required for setup and acquisition of an ECG gated study is not necessary for every patient.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • “Blunt aortic injuries (BAI) represent the second leading cause of death from motor vehicle crashes accounting for 15% of all motor vehicle accident-associated deaths. Death occurs at the scene of the accident in 70–90% of the cases. According to historical case series, the majority of the patients with BAI (75%) who arrive to the hospi- tal alive are hemodynamically stable, but only 10% survive more than 6 h. Patients arriving to the hospital alive most frequently present with injury at the aortic isthmus where periadventitial tissue seems to provide some degree of protection against free rupture. The majority of patients with BAI have an associated closed head injury, multiple rib fractures, lung contusions, or orthopedic injuries.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “The SVS AI grading system is based on the following criteria: (grade I) intimal tear; (grade II) intramural hematoma; (grade III) pseudoaneurysm; (grade IV) rupture. Under this system, grade I-II are considered mild and grade III-IV are considered severe. In our investigation, we created criteria for radiographic severe injury and used this as a binary variable (severe versus the others) rather than creating a full grading system.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “Radiographically severe injuries were those meeting any of the following criteria: total/partial aortic transection, active contrast extravasation, or the association of 2 of more of the following: contained contrast extravasation > 10 mm, periaortic hematoma and/or mediastinal hematoma thicker than 10 mm, or significant left pleural effusion. We evaluated multiple inju- ries where a pseudoaneurysm was found in isolation, without significant associated hematoma or extravasation, which did not meet criteria for RSI. Thus, many injuries that would be graded III by the SVS system were not included in our RSI classification since they did not meet our selection criteria.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “Acute aortic injuries are not common in the setting of severe blunt trauma, but lead to significant morbidity and mortality. High- quality MDCT with 2D MPRs and 3D rendering are essential to identify aortic trauma and distinguish anatomic variants and other forms of aortic pathology from an acute injury. Misinterpretation of mimics of acute aortic injury can lead to unnecessary arteriography and thoracic surgery. Since most traumatic injuries occur in the distal arch, radiologists must be cognizant of the range of appearances of variants related to the ductus diverticulum. Cinematic rendering (CR) is a new 3D post-processing tool that provides even greater anatomic detail than traditional volume rendering. In this case series, CR is used to impart to radiologists a better understanding of various anatomic configurations that can be seen with a ductus diverticulum.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • "Among these is the ductus diverticulum—a remnant of the ductus arteriosus that arises from the lesser curvature of the aortic arch, which can be mistaken for a traumatic aortic pseudoaneurysm, dissection, or incomplete rupture. The distal aortic arch, and in particular the undersurface, is the most common location for acute traumatic aortic injury. Differentiation of a ductus diverticulum from an aortic injury can be difficult, but it is of paramount importance in order to spare patients the morbidity of unnecessary thoracic surgery. This becomes more challenging in the setting of other thoracic traumatic injury, especially mediastinal hematoma, as demonstrated in this case report.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • "Postprocessing with 2D multiplanar reconstructions and 3D rendering has become standard of care in CT angiography. One of the advantages of volume rendering over maximum intensity projection is the ability to convey 3D anatomic relationships. For complex anatomic configurations like the thoracic aorta and pulmonary arteries, the lighting model in cinematic rendering adds even greater anatomic detail, as demonstrated by these cases. The potential added value of cinematic rendering in accurately identifying and characterizing vascular pathology will require further study as this new 3D visualization methodology becomes more widely available.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • “A number of artifacts can mimic a traumatic injury of the thoracic aorta. The classic example is that of the cardiac pulsation artifact, especially in the ascending aorta. If there is any doubt, CT angiography with ECG-gating or a transoesophageal echocardiogram will allow this pathology to be excluded in stable patient. Nonetheless, there remain a number of pitfalls that require particular attention.”
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • “Nonetheless, there remain a number of pitfalls that require particular attention:
    •pseudo ruptures: on lateral aortic imaging there is an accumulation of contrast material in a wall crevice, andthis finding varies in terms of whether or not it points to a pathology. It is usually a congenital abnormality, such as a dilation at the aortic insertion into an arterial canal, known as ductus diverticulum. Sometimes these images correspond to acquired conditions, such as aneurysms or simple or complicated plaques of atherosclerosis.”
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • • mediastinal haematoma of venous origin: not all mediastinal bleeding corresponds to aortic injury. The literature describes trauma injuries to the great veins like the supe-rior vena cava. These injuries are rare but they can be life-threatening;
    • mediastinal haematoma secondary to an extra-aortic injury. It is important to know how to detect abnormalitiesof the supra-aortic vessels, possibly using 3D reconstruct-ions. These dangerous lesions are a therapeutic challenge.They are often associated with aortic injuries although they can sometimes be isolated.
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
Deep Learning

  • ”The continued misperception of AI as a replacement for radiologists is much more of a threat than the development and integration of AI into the practice of diagnostic imaging, as our study suggests that it may erode medical student enthusiasm for the field. This has to potential to reduce incoming talent into the field and ultimately result in a “brain drain.” Radiology has always been at the forefront of technology utilization and education in medicine – MRI, CT, and picture archiving and communication systems are just a few examples. Similarly, AI (and associated data science principles) should be integrated into medical education curricula to enable students to take advantage of this technology as well as dispel any incorrect notions about AI's deleterious effects on the field.”
    Medical Student Perspectives on the Impact of Artificial Intelligence on the Practice of Medicine  
    Christian J. Park, Paul H. Yi, Eliot L. Siegel, MD
    Current Problems in Diagnostic Radiology,Volume 50, Issue 5, 2021, Pages 614-619,
  • Quote on AI
    - ‘AI is perhaps the most transformational technology of our time, and healthcare is perhaps AI’s most pressing application.’
    - Satya Nadella, chief executive officer, Microsoft
  • Quote on AI
    - ‘We think that AI is poised to transform medicine, delivering new, assistive technologies that will empower doctors to better serve their patients. Machine learning has dozens of possible application areas, but healthcare stands out as a remarkable opportunity to benefit people.’
    - Google Health
  • “Healthcare systems around the world face significant challenges in achieving the ‘quadruple aim’ for healthcare: improve population health, improve the patient’s experience of care, enhance caregiver experience and reduce the rising cost of care. Ageing populations, growing burden of chronic diseases and rising costs of healthcare globally are challenging governments, payers, regulators and providers to innovate and transform models of healthcare delivery. Moreover, against a backdrop now catalysed by the global pandemic, healthcare systems find themselves challenged to ‘perform’ (deliver effective, high-quality care) and ‘transform’ care at scale by leveraging real-world data driven insights directly into patient care.”
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • "In particular, cloud computing is enabling the transition of effective and safe AI systems into mainstream healthcare delivery. Cloud computing is providing the computing capacity for the analysis of considerably large amounts of data, at higher speeds and lower costs compared with historic ‘on premises’ infrastructure of healthcare organisations. Indeed, we observe that many technology providers are increasingly seeking to partner with healthcare organisations to drive AI-driven medical innovation enabled by cloud computing and technology-related transformation.”
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • "AI’s strength is in its ability to learn and recognise patterns and relationships from large multidimensional and multimodal datasets; for example, AI systems could translate a patient’s entire medical record into a single number that represents a likely diagnosis. Moreover, AI systems are dynamic and autonomous, learning and adapting as more data become available.”
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • >  ’Supervised learning’ leverages labelled data (annotated information); for example, using labelled X-ray images of known tumours to detect tumours in new images.  
    >  ‘Unsupervised learning’ attempts to extract information from data without labels; for example, categorising groups of patients with similar symptoms to identify a common cause.
    >  ’In reinforcement learning’ RL, computational agents learn by trial and error, or by expert demonstration. The algorithm learns by developing a strategy to maximise rewards. Of note, major breakthroughs in AI in recent years have been based on RL.  
    >  Deep learning (DL) is a class of algorithms that learns by using a large, many-layered collection of connected processes and exposing these processors to a vast set of examples. DL has emerged as the predominant method in AI today driving improvements in areas such as image and speech recognition.
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • >  ’Supervised learning’ leverages labelled data (annotated information); for example, using labelled X-ray images of known tumours to detect tumours in new images.  
    >  ‘Unsupervised learning’ attempts to extract information from data without labels; for example, categorising groups of patients with similar symptoms to identify a common cause.
    >  ’In reinforcement learning’ RL, computational agents learn by trial and error, or by expert demonstration. The algorithm learns by developing a strategy to maximise rewards. Of note, major breakthroughs in AI in recent years have been based on RL.  
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • “We hold the view that AI amplifies and augments, rather than replaces, human intelligence. Hence, when building AI systems in healthcare, it is key to not replace the important elements of the human interaction in medicine but to focus it, and improve the efficiency and effectiveness of that interaction. Moreover, AI innovations in healthcare will come through an in-depth, human- centred understanding of the complexity of patient journeys and care pathways.”
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 

  • Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • “We hold the view that AI amplifies and augments, rather than replaces, human intelligence. Hence, when building AI systems in healthcare, it is key to not replace the important elements of the human interaction in medicine but to focus it, and improve the efficiency and effectiveness of that interaction. Moreover, AI innovations in healthcare will come through an in-depth, human- centred understanding of the complexity of patient journeys and care pathways.”
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • AI today (and in the near future)  
    Currently, AI systems are not reasoning engines ie cannot reason the same way as human physicians, who can draw upon ‘common sense’ or ‘clinical intuition and experience’. Instead, AI resembles a signal translator, translating patterns from datasets. AI systems today are beginning to be adopted by healthcare organisations to automate time consuming, high volume repetitive tasks. Moreover, there is considerable progress in demonstrating the use of AI in precision diagnostics (eg diabetic retinopathy and radiotherapy planning).  
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • AI in the medium term (the next 5–10 years)  
    In the medium term, we propose that there will be significant progress in the development of powerful algorithms that are efficient (eg require less data to train), able to use unlabelled data, and can combine disparate structured and unstructured data including imaging, electronic health data, multi-omic, behavioural and pharmacological data. In addition, healthcare organisations and medical practices will evolve from being adopters of AI platforms, to becoming co-innovators with technology partners in the development of novel AI systems for precision therapeutics.  
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • AI in the long term (>10 years)  In the long term, AI systems will become more intelligent, enabling AI healthcare systems achieve a state of precision medicine through AI-augmented healthcare and connected care. Healthcare will shift from the traditional one-size-fits-all form of medicine to a preventative, personalised, data-driven disease management model that achieves improved patient outcomes (improved patient and clinical experiences of care) in a more cost- effective delivery system.  
    Artificial intelligence in healthcare: transforming the practice of medicine
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • Healthcare leaders should consider (as a minimum) these issues when planning to leverage AI for health:  
    > processes for ethical and responsible access to data: healthcare data is highly sensitive, inconsistent, siloed and not optimised for the purposes of machine learning development, evaluation, implementation and adoption
    > access to domain expertise / prior knowledge to make sense and create some of the rules which need to be applied to the datasets (to generate the necessary insight)
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 
  • Healthcare leaders should consider (as a minimum) these issues when planning to leverage AI for health:  
    > access to sufficient computing power to generate decisions in real time, which is being transformed exponentially with the advent of cloud computing
    > research into implementation: critically, we must consider, explore and research issues which arise when you take the algorithm and put it in the real world, building ‘trusted’ AI algorithms embedded into appropriate workflows.  
    Artificial intelligence in healthcare: transforming the practice of medicine  
    Junaid Bajwa, Usman Munir, Aditya Nori and Bryan Williams  
    Future Healthcare Journal 2021 Vol 8, No 2: e188–94 

  • How FDA Regulates Artificial Intelligence in  Medical Products
    Pew Charitable Trusts July 2021 
  • Glossary for AI Terms
    - Explainability: The ability for developers to explain in plain language how their data will be used. 
    - Generalizability: The accuracy with which results or findings can be transferred to other situations or people outside of those originally studied.
    - Good Machine Learning Practices (GMLP): AI/ML best practices (such as those for data management or evaluation), analogous to good software engineering practices or quality system practices. 
    - Machine learning (ML): An AI technique that can be used to design and train software algorithms to learn from and act on data. These algorithms can be “locked,” so that their function does not change, or “adaptive,” meaning that their behavior can change over time. 
    - Software as a Medical Device (SaMD): Defined by the International Medical Device Regulators Forum as “software intended to be used for one or more medical purposes that perform these purposes without being part of a hardware medical device.” 
    - Pew Charitable Trusts July 2021
  • Introduction: Concerns about radiologists being replaced by artificial intelligence (AI) from the lay media could have a negative impact on medical students’ per- ceptions of radiology as a viable specialty. The purpose of this study was to evaluate United States of America medical students’ perceptions about radiology and other medical specialties in relation to AI.
    Conclusions: US medical students believe that AI will play a significant role in medicine, particularly in radiology. However, nearly half are less enthusiastic about the field of radiology due to AI. As the majority receive information about AI from online articles, which may have negative sentiments towards AI’s impact on radiology, formal AI education and medical student outreach may help combat misinformation and help prevent the dissuading of medical students who might otherwise consider the specialty.  
    Medical Student Perspectives on the Impact of Artificial Intelligence on the Practice of Medicine  
    Christian J. Park, Paul H. Yi, Eliot L. Siegel, MD
    Current Problems in Diagnostic Radiology,Volume 50, Issue 5, 2021, Pages 614-619,

  • Medical Student Perspectives on the Impact of Artificial Intelligence on the Practice of Medicine  
    Christian J. Park, Paul H. Yi, Eliot L. Siegel, MD
    Current Problems in Diagnostic Radiology,Volume 50, Issue 5, 2021, Pages 614-619, 
  •  “Interestingly, of the respondents who chose radiology to be the most significantly impacted, 44% said that it would reduce their enthusiasm. This is a similar proportion compared to a recent survey that was performed in Europe, which found that less than half (44%) of respondents felt that this would reduce enthusiasm for the field of radiology a sentiment that was echoed in a recent survey of Canadian medical students, in which 48.6% stated that AI caused them to feel anxious regarding a career in radiology. The significance of this is not to be understated in that half of potential candidates to the specialty feel as though there is limited opportunity due to an emerging technology such as AI. These sentiments have the potential to create downstream effects, such as reduction in recruitment to the field of radiology or even medicine as whole”
    Medical Student Perspectives on the Impact of Artificial Intelligence on the Practice of Medicine  
    Christian J. Park, Paul H. Yi, Eliot L. Siegel, MD
    Current Problems in Diagnostic Radiology,Volume 50, Issue 5, 2021, Pages 614-619, 
  • “On the other hand, machine learning (ML) algorithms—also referred to as a data-based approach—“learn”  from numerous examples in a dataset without being explicitly programmed to reach a particular answer or conclusion. ML algorithms can learn to decipher patterns in patient data at scales larger than a human can analyze while also potentially uncovering previously unrecognized correlations. Algorithms may also work at a faster pace than a human.”
    How FDA Regulates Artificial Intelligence in  Medical Products
    Pew Charitable Trusts July 2021 
  • "Most ML-driven applications use a supervised approach in which the data used to train and validate the algorithm is labeled in advance by humans; for example, a collection of chest X-rays taken of people who have lung cancer and those who do not, with the two groups identified for the AI software. The algorithm examines all examples within the training dataset to “learn” which features of a chest X-ray are most closely correlated with the diagnosis of lung cancer and uses that analysis to predict new cases. Developers then test the algorithm to see how generalizable it is; that is, how well it performs on a new dataset, in this case, a new set of chest X-rays. Further validation is required by the end user, such as the health care practice, to ensure that the algorithm is accurate in real-world settings.”
    How FDA Regulates Artificial Intelligence in  Medical Products
    Pew Charitable Trusts July 2021 
  • "Locked algorithms can degrade as new treatments and clinical practices arise or as populations alter overtime. These inevitable changes may make the real-world data entered into the AI program vastly different from its training data, leading the software to yield less accurate results. An adaptive algorithm could present an advantage in such situations, because it may learn to calibrate its recommendations in response to new data, potentially becoming more accurate than a locked model. However, allowing an adaptive algorithm to learn and adapt on its own also presents risks, including that it may infer patterns from biased practices or underperform in small subgroups of patients.”
    How FDA Regulates Artificial Intelligence in  Medical Products
    Pew Charitable Trusts July 2021 
  • "In addition, patients are often not aware when an AI program has influenced the course of their care; these tools could, for example, be part of the reason a patient does not receive a certain treatment or is recommended fora potentially unnecessary procedure. Although there are many aspects of health care that a patient may not fully understand, in a recent patient engagement meeting hosted by FDA, some committee members—including patient advocates—expressed a desire to be notified when an AI product is part of their care. This desire included knowing if the data the model was trained on was representative of their particular demographics, or if it had been modified in some way that changed its intended use.”
    How FDA Regulates Artificial Intelligence in  Medical Products
    Pew Charitable Trusts July 2021 
  • “Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of mortality among all cancers. It ranked fifth among all cancers in terms of mortality and its overall 5-year survival rate was just 6% in Korea for 2015. Surgical resection is essential for its cure but only a small proportion of its cases are found at an early stage enough for the procedure. Moreover, its recurrence rate after surgery is estimated to be 50%–60%, while its 5-year survival rate after surgery is reported to be just 20%–30% . The mean disease-free period in imaging studies is 267 ± 158 d with negative surgical margins, but 72 ± 47 d with positive margins. Therefore the survival of patients with PDAC is closely related to recurrence, and recurrence after surgery is one of the typical characteristics of PDAC .”
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • "It is very important to prevent the recurrence of pancreatic cancer after surgery and there has been strong endeavor to identify major predictors of its disease-free survival after surgery. However, the results of existing literature were inconsistent and predictors in these studies were unmodifiable in general. Predictive nomograms were developed to combine and visualize the findings of traditional statistical models such as logistic regression and the Cox model regarding the recurrence of pancreatic cancer after surgery. But the predictive nomograms still require unrealistic assumptions of the traditional statistical models, i.e., ceteris paribus, “all the other variables staying constant”. In this context, this study used the random forest and multi-center registry data to analyze the recurrence of pancreatic cancer after surgery and its major determinants.”
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • "Secondly, it was beyond the scope of this study to combine deep learning and the Cox model for predicting the recurrence of pancreatic cancer after surgery. Deep learning can be defined as “a sub-group of the artificial neural network whose number of hidden layers is larger than five, e.g., ten”. The last three years have seen the emergence of new strands of research to combine the Cox model with different types of its deep-learning counterparts. The continued development and application of these cutting-edge approaches would break new ground and bring more profound clinical insights regarding the recurrence of pancreatic cancer after surgery and its major determinants.”
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • ”Early detection of postoperative complications, including organ failure, is pivotal in the initiation of targeted treatment strategies aimed at attenuating organ damage. In an era of increasing health-care costs and limited financial resources, identifying surgical patients at a high risk of postoperative complications and providing personalised precision medicine-based treatment strategies provides an obvious pathway for reducing patient morbidity and mortality. We aimed to leverage deep learning to create, through training on structured electronic health-care data, a multilabel deep neural network to predict surgical postoperative complications that would outperform available models in surgical risk prediction.”
    Assessing the utility of deep neural networks in predicting  postoperative surgical complications: a retrospective study  
    Alexander Bonde  et al.
  • "In this retrospective study, we used data on 58 input features, including demographics, laboratory values, and 30-day postoperative complications, from the American College of Surgeons (ACS) National Surgical Quality Improvement Program database, which collects data from 722 hospitals from around 15 countries. We queried the entire adult (≥18 years) database for patients who had surgery between Jan 1, 2012, and Dec 31, 2018. We then identified all patients who were treated at a large midwestern US academic medical centre, excluded them from the base dataset, and reserved this independent group for final model testing. We then randomly created a training set and a validation set from the remaining cases.”
    Assessing the utility of deep neural networks in predicting  postoperative surgical complications: a retrospective study  
    Alexander Bonde  et al.
    Lancet Digit Health 2021; 3: e471–85 Lancet Digit Health 2021; 3: e471–85 
  • “We have developed unified prediction models, based on deep neural networks, for predicting surgical postoperative complications. The models were generally superior to previously published surgical risk prediction tools and appeared robust to changes in the underlying patient population. Deep learning could offer superior approaches to surgical risk prediction in clinical practice.”
    Assessing the utility of deep neural networks in predicting  postoperative surgical complications: a retrospective study  
    Alexander Bonde  et al.
    Lancet Digit Health 2021; 3: e471–85 
  • Implications of all the available evidence  
    ”Our deep learning models were superior to previously published surgical risk prediction tools, despite the increasingly rigorous standards for model validation. Our algorithms might be used by clinicians to help guide future preoperative, intraoperative, and postoperative risk management, serving as an important step towards personalised medicine in surgery. A clinical trial is required to identify whether the use of deep learning models can help to reduce the incidence of surgical postoperative complications.”
    Assessing the utility of deep neural networks in predicting  postoperative surgical complications: a retrospective study  
    Alexander Bonde  et al.
    Lancet Digit Health 2021; 3: e471–85 
  • Background: or Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of mortality in the world with the overall 5-year survival rate of 6%. The survival of patients with PDAC is closely related to recurrence and therefore it is necessary to identify the risk factors for recurrence. This study uses artificial intelligence approaches and multi-center registry data to analyze the recurrence of pancreatic cancer after surgery and its major determinants.  
    Results: Based on variable importance from the random forest, major predictors of disease-free survival after surgery were tumor size (0.00310), tumor grade (0.00211), TNM stage (0.00211), T stage (0.00146) and lymphovascular invasion (0.00125). The coefficients of these variables were statistically significant in the Cox model (p < 0.05). The C-Index averages of the random forest and the Cox model were 0.6805 and 0.7738, respectively.  
    Conclusions: This is the first artificial-intelligence study with multi-center registry data to predict disease-free survival after the surgery of pancreatic cancer. The findings of this methodological study demonstrate that artificial intelligence can provide a valuable decision-support system for treating patients undergoing surgery for pancreatic cancer. However, at present, further studies are needed to demonstrate the actual benefit of applying machine learning algorithms in clinical practice.  
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • Results: Based on variable importance from the random forest, major predictors of disease-free survival after surgery were tumor size (0.00310), tumor grade (0.00211), TNM stage (0.00211), T stage (0.00146) and lymphovascular invasion (0.00125). The coefficients of these variables were statistically significant in the Cox model (p < 0.05). The C-Index averages of the random forest and the Cox model were 0.6805 and 0.7738, respectively.  
    Conclusions: This is the first artificial-intelligence study with multi-center registry data to predict disease-free survival after the surgery of pancreatic cancer. The findings of this methodological study demonstrate that artificial intelligence can provide a valuable decision-support system for treating patients undergoing surgery for pancreatic cancer. However, at present, further studies are needed to demonstrate the actual benefit of applying machine learning algorithms in clinical practice.  
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
Kidney

  • “Myeloid sarcoma (MS), also known as “granulocytic sarcoma” or “chloroma”, is a solid extramedullary tumor mass composed of malignant primitive myeloid cells. By definition, the infiltrates efface the underlying tissue architecture. In the 2016 revision to the World Health Organization classification of myeloid neoplasms and acute leukemia, MS is described as a unique clinical presentation of any subtype of acute myeloid leukemia (AML). The etiology of MS is still unknown. Myeloid sarcoma may present de novo, accompany peripheral blood and marrow involvement, present as relapse of acute myeloid leukemia, or as progression of a prior myelodysplastic syndrome (MDS), myeloproliferative neoplasm (MPN), or MDS/MPN. Seldom precedes MS the development of the hematologic disease.”
    Myeloid Sarcoma Involving Kidneys: From Diagnosis to Treatment. Case Report and Literature Review
    Francesca Guidotti et al.
    CMI 2020; 14(1): 39-44
  • "MS radiologically appear as soft tissue masses on plain CT and as well-defined homogeneously enhanced masses on enhanced CT. Differential diagnoses of renal MS on CT mainly include insignificantly enhanced renal cell carcinomas, renal infarctions, and renal lymphomas. Unlike renal MS, insignificantly enhanced renal cell carcinomas are usually singular and prone to hemorrhage, necrosis, and cystic changes in the lesions. Renal infarctions are usually wedge-shaped with no mass effect and enhanced cortical rim signs representative of cortical rims and renal vessel abnormalities on the lesion side may be observed on contrast-enhanced CT images.”
    Myeloid Sarcoma Involving Kidneys: From Diagnosis to Treatment. Case Report and Literature Review
    Francesca Guidotti et al.
    CMI 2020; 14(1): 39-44
  • "When MS occurs as a presenting feature before the onset of overt leukemia, it is often misdiagnosed as lymphoma. A review of 72 patients of non-leukemic MS showed that 35 patients (47%) were initially misdiagnosed, most often (31/35) as malignant lymphoma. The morphological similarity of blasts with lymphoma cells, especially in the blastic and undifferentiated variant of MS and its rarity, resulting in low index of suspicion, have been reported as the main reasons for the misdiagnosis in such cases.”
    Myeloid Sarcoma Involving Kidneys: From Diagnosis to Treatment. Case Report and Literature Review
    Francesca Guidotti et al.
    CMI 2020; 14(1): 39-44
  • “Myeloid sarcoma is an extramedullary tumor of immature granulocytic cells. It is a rare condition, most often associated with acute myeloid leukemia (AML), although in some rare cases it may present in nonleukemic patients. It should therefore be considered as a differential diagnosis of any atypical cellular infiltrate. It may occur at any site, leading to very varied clinical presentations. Diagnosis is challenging and relies on a high index of suspicion as well as radiology, histology, immunophenotyping, and molecular analyses, which also are essential for risk stratification and treatment planning. Systemic chemotherapy using AML-like regimens should be commenced early, even in nonleukemic disease.”
    Myeloid Sarcoma: Presentation, Diagnosis, and Treatment.
     Almond LM et al.  
    Clin Lymphoma Myeloma Leuk. 2017 May;17(5):263-267
  • Erdheim–Chester disease:  Renal Findings
    - enlarged kidneys 
    - perirenal infiltrations shown as characteristic “hairy kidney” (70%)
    - Renal sinus involvement
    - Thickening of the ureters
    - Soft tissue thickening of the renal arteries
  • “In summary, urinary involvement in ECD was mostly bilateral and symmetric. Early identification of the perirenal hairy kidney sign is critical for accurate diagnosis and timely treatment. Understanding of the CT findings and progression as well as correct diagnosis based on radiological findings, have significant implications for guiding ECD treatment.”  
    Urinary involvement in Erdheim–Chester disease: computed tomography imaging findings  
    Zhe Wu et al.
    Abdominal Radiology (2021) 46:4324–4331 
  • Erdheim Chester Disease: Renal Changes
    - Perirenal fat effaced or infiltrated by soft tissue
    - Usually bilateral and symmetric
    - Infiltration of para-aortic regions is also common
  • Erdheim Chester Disease: Vascular Changes
    - Periaortic infiltration which is usually circumferential and nonocclusive
    - May involve aorta from root thru iliac vessels
    - May involve the renal arteries
  • Erdheim Chester Disease: Skeletal Changes
    - Bilateral symmetric osteosclerosis of metaphyses and diaphyses especially in long bone.
  • Purpose To describe the urological manifestations of Erdheim–Chester disease (ECD) and their computed tomography (CT) findings.
    Methods We retrospectively reviewed 48 patients diagnosed with ECD at Peking Union Medical College Hospital from January 2014 to January 2020. Twenty-four patients exhibited urological manifestations. Their CT findings, including appear- ances of the involved area (e.g., perirenal space, renal sinus, ureters, renal arteries, and adrenal glands), occurrence rate of ECD involvement in each area, signal enhancement pattern after CT contrast agent administration, disease progression, and causes of hydronephrosis were discussed.  
    Results In 24 patients with evidence of ECD urological involvement, the most common manifestation was perirenal infiltra- tion, appearing as “hairy kidney” on unenhanced CT scans and moderate signal enhancement on enhanced CT scans (17/24, 70.8%). Other manifestations included renal sinus infiltration (16/24, 66.7%), proximal ureter involvement (14, 58.3%), renal artery sheath (10, 41.7%), hydronephrosis (14, 58.3%), and adrenal glands involvement (8, 33.3%). The histiocytic infiltrate was mostly bilateral, starting from the perirenal space and spreading to the renal sinus and ureters. Hydronephrosis was usually associated with infiltration of ureters.  
    Conclusion Kidneys are the most common visceral organs affected by ECD. CT scanning is not only advantageous in early diagnosis, but also critical for designing the treatment regime for patients with ECD.  
    Urinary involvement in Erdheim–Chester disease: computed tomography imaging findings  
    Zhe Wu et al.
    Abdominal Radiology (2021) 46:4324–4331 
  • Purpose To describe the urological manifestations of Erdheim–Chester disease (ECD) and their computed tomography (CT) findings.
    Results In 24 patients with evidence of ECD urological involvement, the most common manifestation was perirenal infiltration, appearing as “hairy kidney” on unenhanced CT scans and moderate signal enhancement on enhanced CT scans (17/24, 70.8%). Other manifestations included renal sinus infiltration (16/24, 66.7%), proximal ureter involvement (14, 58.3%), renal artery sheath (10, 41.7%), hydronephrosis (14, 58.3%), and adrenal glands involvement (8, 33.3%). The histiocytic infiltrate was mostly bilateral, starting from the perirenal space and spreading to the renal sinus and ureters. Hydronephrosis was usually associated with infiltration of ureters.  
    Conclusion Kidneys are the most common visceral organs affected by ECD. CT scanning is not only advantageous in early diagnosis, but also critical for designing the treatment regime for patients with ECD.  
    Urinary involvement in Erdheim–Chester disease: computed tomography imaging findings  
    Zhe Wu et al.
    Abdominal Radiology (2021) 46:4324–4331 
Pancreas

  • Background: or Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of mortality in the world with the overall 5-year survival rate of 6%. The survival of patients with PDAC is closely related to recurrence and therefore it is necessary to identify the risk factors for recurrence. This study uses artificial intelligence approaches and multi-center registry data to analyze the recurrence of pancreatic cancer after surgery and its major determinants.  
    Results: Based on variable importance from the random forest, major predictors of disease-free survival after surgery were tumor size (0.00310), tumor grade (0.00211), TNM stage (0.00211), T stage (0.00146) and lymphovascular invasion (0.00125). The coefficients of these variables were statistically significant in the Cox model (p < 0.05). The C-Index averages of the random forest and the Cox model were 0.6805 and 0.7738, respectively.  
    Conclusions: This is the first artificial-intelligence study with multi-center registry data to predict disease-free survival after the surgery of pancreatic cancer. The findings of this methodological study demonstrate that artificial intelligence can provide a valuable decision-support system for treating patients undergoing surgery for pancreatic cancer. However, at present, further studies are needed to demonstrate the actual benefit of applying machine learning algorithms in clinical practice.  
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • Results: Based on variable importance from the random forest, major predictors of disease-free survival after surgery were tumor size (0.00310), tumor grade (0.00211), TNM stage (0.00211), T stage (0.00146) and lymphovascular invasion (0.00125). The coefficients of these variables were statistically significant in the Cox model (p < 0.05). The C-Index averages of the random forest and the Cox model were 0.6805 and 0.7738, respectively.  
    Conclusions: This is the first artificial-intelligence study with multi-center registry data to predict disease-free survival after the surgery of pancreatic cancer. The findings of this methodological study demonstrate that artificial intelligence can provide a valuable decision-support system for treating patients undergoing surgery for pancreatic cancer. However, at present, further studies are needed to demonstrate the actual benefit of applying machine learning algorithms in clinical practice.  
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • “Pancreatic ductal adenocarcinoma (PDAC) is a leading cause of mortality among all cancers. It ranked fifth among all cancers in terms of mortality and its overall 5-year survival rate was just 6% in Korea for 2015. Surgical resection is essential for its cure but only a small proportion of its cases are found at an early stage enough for the procedure. Moreover, its recurrence rate after surgery is estimated to be 50%–60%, while its 5-year survival rate after surgery is reported to be just 20%–30% . The mean disease-free period in imaging studies is 267 ± 158 d with negative surgical margins, but 72 ± 47 d with positive margins. Therefore the survival of patients with PDAC is closely related to recurrence, and recurrence after surgery is one of the typical characteristics of PDAC .”
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • "It is very important to prevent the recurrence of pancreatic cancer after surgery and there has been strong endeavor to identify major predictors of its disease-free survival after surgery. However, the results of existing literature were inconsistent and predictors in these studies were unmodifiable in general. Predictive nomograms were developed to combine and visualize the findings of traditional statistical models such as logistic regression and the Cox model regarding the recurrence of pancreatic cancer after surgery. But the predictive nomograms still require unrealistic assumptions of the traditional statistical models, i.e., ceteris paribus, “all the other variables staying constant”. In this context, this study used the random forest and multi-center registry data to analyze the recurrence of pancreatic cancer after surgery and its major determinants.”
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • ”Secondly, it was beyond the scope of this study to combine deep learning and the Cox model for predicting the recurrence of pancreatic cancer after surgery. Deep learning can be defined as “a sub-group of the artificial neural network whose number of hidden layers is larger than five, e.g., ten”. The last three years have seen the emergence of new strands of research to combine the Cox model with different types of its deep-learning counterparts. The continued development and application of these cutting-edge approaches would break new ground and bring more profound clinical insights regarding the recurrence of pancreatic cancer after surgery and its major determinants.”
    Usefulness of artificial intelligence for predicting recurrence following surgery for pancreatic cancer: Retrospective cohort study  
    Kwang-Sig Lee et al.
    International Journal of Surgery 93 (2021) 106050 
  • "Ectopic pancreas, also referred to as heterotopic, accessory, or aberrant pancreas, is defined as pancreatic tissue lacking anatomic and vascular continuity with the main body of the gland; an ectopic pancreas is usually located in the stomach, duodenum, or jejunum. Most of the lesions are small and asymptomatic.”
    Ectopic Pancreas: CT Findings with Emphasis on Differentiation from Small Gastrointestinal Stromal Tumor and Leiomyoma
    Kim JY et al.
    Radiology 2009; 252:92–100 
  • “Prepyloric antral or duodenal location, endoluminal growth pattern, ill-defined border, promi- nent enhancement of overlying mucosa, and long diameter to short diameter ratio greater than 1.4 were found to be significant CT imaging findings for differentiating ectopic pancreas from other submucosal tumors.”
    Ectopic Pancreas: CT Findings with Emphasis on Differentiation from Small Gastrointestinal Stromal Tumor and Leiomyoma
    Kim JY et al.
    Radiology 2009; 252:92–100 
  • "Ectopic pancreas may manifest as a submucosal mass in the stomach or duodenum and may easily be misinterpreted as another submucosal tumor such as gastrointestinal stromal tumor (GIST) or leiomyoma on imaging studies or at endoscopic examinations, including endoscopic ultra- sonography (US). Because GISTs are by far the most common submucosal tumors of the stomach and constitute about 90% of gastric submucosal tumors, ectopic pancreas can frequently be mistaken for GIST or leiomyoma at endoscopy, US, or computed tomographic (CT) scanning.”
    Ectopic Pancreas: CT Findings with Emphasis on Differentiation from Small Gastrointestinal Stromal Tumor and Leiomyoma
    Kim JY et al.
    Radiology 2009; 252:92–100 
  • “In conclusion, ectopic pancreas of the stomach and duodenum has characteris- tic CT findings that differ from those of gastric submucosal tumors such as GIST and leiomyoma. When characteristic CT imaging findings are used in combination, ectopic pancreas can be differentiated from submucosal tumors with a high de- gree of diagnostic accuracy.”
    Ectopic Pancreas: CT Findings with Emphasis on Differentiation from Small Gastrointestinal Stromal Tumor and Leiomyoma
    Kim JY et al.
    Radiology 2009; 252:92–100 
Spleen

  • “Splenic artery aneurysms are the most frequent of visceral artery aneurysms. Splenic artery aneurysms may be intra or extra-splenic and most of the cases are calcified. If it measures more than 2.0 cm, there is high risk of rupture (76% fatal), and are often treated.Women with more than two pregnancies have high predisposition to aneurysm rupture and are often treated more aggressively.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • “Angiosarcoma is an extremely rare tumor but is the most common primary non-hematolymphoid malignancy. It is an extremely aggressive neoplasm with widespread metastasis and splenic rupture common presenting manifestations. The most common CT finding is a patient with splenomegaly (60%) containing a large heterogenous solid mass or masses that nearly replace the spleen.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • "Splenosis typically consists of multiple small implants of splenic tissue; it can mimic peritoneal carcinomatosis or endometriosis depending on the clinical context.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396,
  • "The syndrome of polysplenia is often accompanied by a variable spectrum of visceral and vascular developmental anomalies. It is rarely diagnosed in adults. While it is estimated that 2.5/100,000 infants are born with this anomally, fewer than 5% are still alive at five years of age due to the associated severe cardiac anomalies.The syndrome is associated with multiple congenital malformations that may involve the solid organs and digestive tube of the abdominal cavity, the heart, or the great vessels. The diagnosis is often made during surgical exploration for an associated cardiac or digestive anomaly. Among the most common vascular anomalies are agenesis of the suprarenal inferior vena cava with persistent continuity of the azygos vein, and pre-duodenal position of the portal vein. Biliary atresia is found in nearly 50% of cases, common mesentery in more than 75% of cases, and an abbreviated or annular pancreas in 85–90% of cases.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396
  • “ Anomalies include asplenia, the congenital absence of the spleen. This can be isolated or part of a clinical sequela of a broader syndrome such as Ivermark syndrome, a heterotaxy syndrome occurring in 1 in 10,000 to 40,000 cases. CT will show lack of spleen and Tc-99 red blood cell scan will show lack of uptake.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • "Accessory spleen is a frequent congenital variation (20% of autopsy) due to failure in coalescence of mesodermal buds in the dorsal mesogastrium.The accessory spleen is supplied by the splenic artery and most are located near the splenic hilum. On pre- and post-contrast imaging, this enhances similarly to splenic parenchyma. This entity is important to recognize because it could be responsible for the recurrence of hematologic disorders after splenectomy.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • "Splenosis in an acquired condition that occurs after splenectomy or splenic rupture is represented by seeding or implantation of splenic cells in any location, frequently simulating tumors. On pre- and post-contrast, imaging, splenosis appears similar to the normal spleen. When ectopic splenic tissue or splenosis is in the differential for a mass around the splenic hilum or splenectomy bed, a technetium tagged heat-damaged red blood cell scan is a nuclear medicine examination that can delineate ectopic splenic tissue. Splenosis is usually managed conservatively and history is key to help differentiate it from other lesions.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • Anatomy of the spleen
    Macroscopic anatomy
    - An intraperitoneal organ, almost entirely surrounded by the peritoneum, which firmly adherent to the capsule.
    - The splenic hilum is usually directed anteromedially, and the splenic artery and vein enters the spleen in this region through the splenorenal ligament. 
    - The splenorenal and gastrosplenic ligaments are the two folds of peritoneum that hold the spleen in its position. 
    - Normal splenic size: approximately 200g, 12 cm length, 3-4 cm thickness, 7 cm width.
    Histological anatomy
    - Red pulp: Complex network of sinusoids and splenic cords
    -- Functions as a filter and blood flow regulator
    -- The site of erythrocyte storage and macrophage proliferation and differentiation
    - White pulp: Consists of lymphatic tissue, contains germinal centers.
    -- The site of the spleen’s immunological and cytopoietic function
    - Marginal zone: An ill-defined interphase between red/white pulp.
    - Transient heterogeneous pattern of contrast enhancement is thought to be related to the variable rates of blood flow through the red/white pulp.
  • Normal Variant Anatomy of the Spleen
    Splenic cleft and lobulation
    - The cleft on the superior border are remnants of the groves that originally separated the fetal lobules, and can simulate lacerations.
    Accessory spleen
    - Found in 10-20% of individuals. 
    - Within the tail of the pancreas is the second common site of the accessory spleen, and can mimic hypervascular pancreatic tumor (e.g. neuroendocrine tumor)
    - Accessory spleen can be a site of relapse of hypersplenism after splenectomy in patients with a hematologic disorder with hypersplenism.
    Splenosis
    - Ectopic splenic tissue caused by autotransplantation of splenic cells resulting from traumatic disruption of the splenic capsule via trauma or surgery. 
    - More numerous and widespread than accessory spleens.
  • Normal Variant Anatomy of the Spleen 
    Wandering spleen
    - The spleen migrate from its normal position due to congenital or acquired laxity of the splenic suspensory ligament.
    - At risk of vascular pedicle torsion and splenic infarct.
    Polysplenia 
    - A rare complex syndrome, consists of situs ambiguous with features of left isomerism (bilateral left-sidedness)
    - Multiple spleen in right or left upper quadrant, single, lobulated spleen, or a normal spleen
    - Anomalous position of abdominal viscera, short pancreas, abnormal bowel rotation, cardiovascular anomalies
    Asplenia
    - Absent spleen, situs ambiguous, multiple anomalies including cardiovascular anomalies (typically more complex than those with polysplenia), bowel malrotation, genitourinary tract anomalies.
  • Normal Variant Anatomy of the Spleen
    Accessory spleen
    - Found in 10-20% of individuals. 
    - Within the tail of the pancreas is the second common site of the accessory spleen, and can mimic hypervascular pancreatic tumor (e.g. neuroendocrine tumor)
    - Accessory spleen can be a site of relapse of hypersplenism after splenectomy in patients with a hematologic disorder with hypersplenism.
    Splenosis
    - Ectopic splenic tissue caused by autotransplantation of splenic cells resulting from traumatic disruption of the splenic capsule via trauma or surgery. 
    - More numerous and widespread than accessory spleens.
  • Normal Variant Anatomy of the Spleen
    Polysplenia 
    - A rare complex syndrome, consists of situs ambiguous with features of left isomerism (bilateral left-sidedness)
    - Multiple spleen in right or left upper quadrant, single, lobulated spleen, or a normal spleen
    - Anomalous position of abdominal viscera, short pancreas, abnormal bowel rotation, cardiovascular anomalies
    Asplenia
    - Absent spleen, situs ambiguous, multiple anomalies including cardiovascular anomalies (typically more complex than those with polysplenia), bowel malrotation, genitourinary tract anomalies.
  • Normal Variant Anatomy of the Spleen 
    Wandering spleen
    - The spleen migrate from its normal position due to congenital or acquired laxity of the splenic suspensory ligament.
    - At risk of vascular pedicle torsion and splenic infarct.
  • Pitfalls in Evaluation of the Spleen
    - Splenic tissue simulating an islet cell tumor of the pancreas (usually accessory spleen)
    - Splenic tissue in the pancreas simulating an islet cell tumor
    - Post left nephrectomy splenic rotation simulating a tumor recurrence
  • “Wandering spleen is a very rare defect characterized by the absence or weakness of one or more of the ligaments that hold the spleen in its normal position in the upper left abdomen. Patient symptomatology is variable and ranges from mere feeling of an abdominal lump to sudden abdominal pain due to infarction. Patients may have subacute to chronic abdominal or gastrointestinal complaints. Because of nonspecific symptoms, clinical diagnosis can be difficult; hence, imaging plays an important role. A major complication is splenic torsion, which is the cause of acute abdomen.”
    Acute abdomen due to torsion of the wandering spleen in a patient with Marfan Syndrome  
    Laura Leci-Tahiri et al.
    World Journal of Emergency Surgery 2013, 8:30
  • “The possible diagnosis of wandering spleen should be kept in mind when CT shows the spleen to be absent from its usual position and a mass is found elsewhere in the abdomen or pelvis. Abdominal ultrasonography (with or without Doppler) and CT are useful investigative tools. Early intervention is necessary to reduce the risk of splenic infarction and other complications. An awareness of the condition together with the use of appropriate medical imaging can lead to the correct diagnosis.”
    Acute abdomen due to torsion of the wandering spleen in a patient with Marfan Syndrome  
    Laura Leci-Tahiri et al.
    World Journal of Emergency Surgery 2013, 8:30
  • Interruption of the inferior vena cava: facts
    - Interruption of the inferior vena cava (IVC) with azygos continuation is a rare congenital anomaly, in which the IVC is interrupted below the hepatic vein and venous return beyond this point is restored by the dilated azygos and hemiazygos veins draining into the superior vena cava.
    - this congenital anomaly could be isolated, but often it is part of more complex syndrome including for example cardiac malformations, asplenia, and polysplenia syndrome. Interruption of the IVC with azygos continuation is the second most common abnormality associated with polysplenia syndrome 
  • “The polysplenic syndrome is defined by the presence of multiple spleens, usually numbering between two and six. In contrast to accessory spleens, the spleens are of uniform size. Accessory spleens usually measure between 1 and 2 cm and are not considered as a form of the polysplenic syndrome. Splenosis, an acquired rather than congenital condition that arises in the context of traumatic splenic rupture, can be ruled out by patient history.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396,
Trauma

  • Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important.
    Main body: Blunt thoracic aortic injury may be fatal if not diagnosed and treated expeditiously. Endovascular options allow safe and effective management of these dangerous injuries. This paper describes the overview of blunt thoracic aortic trauma, the epidemiology, presentation, diagnosis, and treatment options with a focus on endovascular management.  
    Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.  
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62 
  • Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important. and treatment options with a focus on endovascular management.  
    Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.  
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62 
  • “Up to 80% of patients presenting with blunt thoracic aortic injury(BTAI) die before hospitalization, and in the remaining survivors, in- hospital mortality is as high as 46%. While this is a potentially lethal injury, it is rare and accounts for 1.5% of thoracic trauma.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Rapid deceleration is the universal mechanism of this injury. Most commonly, there are multiple other life- threatening injuries present with less than 20% having this as an isolated injury making the diagnosis and initial next steps challenging. BTAI is defined as a tear in the aorta that is a result of a combination of shear and stretch forces, rapid deceleration, increased intravascular pressure and compression of the aorta between the anterior chest wall and vertebrae.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Injury can occur along the entire length of the aorta, essentially from the ascending aorta to the iliac bifurcation, although the injury typically occurs areas of aortic tethering, notably the aortic isthmus.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “Blunt thoracic aortic trauma is associated with other major entities of chest trauma, including, but not limited to, sternal fracture, 1st/2nd rib fractures, clavicle and/or scapular fractures, pneumothoraces, hemothoraces, flail chest, pulmonary contusions, diaphragm injury, tracheobronchial disruption and esophageal injuries; these should raise suspicion for BTAI.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Injuries are assigned one of 4 grades based on CTA imaging: grade 1 (intimal tear), grade II (intramural hematoma), grade III (pseudoaneurysm) and grade IV (rupture). Currently, the recommendation is to proceed with surgical repair of Grade II-IV injuries [20]. For grade I injuries, it is well established that no intervention is necessary as these tend to resolve on their own with conservative management. Grade II injures do fall into a “gray zone” between medical management and operative intervention although more recent studies do document that nonoperative is safe with close follow up.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular approaches have slowly replaced open surgical repair for the management of this pathology. Clearly, such patients that present with blunt thoracic injury should be relegated to centers that specialize in the polytrauma patient as it is their concurrent injuries that are the focus of their critical care.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “The CT findings of TAI can be divided into direct signs of injury and indirect or associated findings. Direct findings of aortic injury include intramural hematoma, intimal flap and pseudoaneurysm. Injuries that only involve the intima, classified as minimal aortic injuries, should only have direct findings of TAI. Minimal aortic injuries can present with an intimal flap, intraluminal aortic thrombus or intramural hematoma. With the improvement in technology allowing thinner CT slice thickness minimal aortic injuries are being diagnosed more frequently.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "Ductal remnants, a diverticulum or small bump, are normal remnants of the embryologic ductus arteriosus. This normal variant can simulate injury and can be very perplexing for the inexperienced or unaware radiologist. The ductal diverticulum is a remnant of the closed or partially closed ductus arteriosus which connects the pulmonary artery to the aorta in fetal circulation. Ductal remnants are located at the inferior surface of the aortic arch near the aortic isthmus which leads to their confusion with TAIs. Ductal remnants are typically smooth walled and have obtuse margins that are continuous with the aortic wall and are often calcified. The presence of calcification can be very helpful in distinguishing a ductal remnant from a TAI with the presence of calcification favoring a benign ductal remnant.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "Mediastinal hematomas can be due to injury to other structures including the pulmonary artery, great vessels or mediastinal veins, or even fractures of vertebral bodies. Presence of a mediastinal hematoma should prompt a careful search for an aortic, pulmonary artery or great vessel injury. In the absence of an identified arterial injury the hematoma is likely venous. A preserved fat plane around the aorta or hematoma centered away from the aorta is less likely to be associated with aortic injury and more likely to be venous.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "The best way to distinguish a true aortic root injury from motion artifact is to repeat thoracic imaging with ECG gating; and echocardiography can be a reasonable alternative. The difference between a study done without and with ECG gating is illustrated in. In our institution all of the chest CT done as part of a trauma survey are acquired without ECG gating. Since the majority of TAIs are at the aortic isthmus, which is typically well seen on non-gated studies, we feel the additional radiation exposure and time required for setup and acquisition of an ECG gated study is not necessary for every patient.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • “Blunt aortic injuries (BAI) represent the second leading cause of death from motor vehicle crashes accounting for 15% of all motor vehicle accident-associated deaths. Death occurs at the scene of the accident in 70–90% of the cases. According to historical case series, the majority of the patients with BAI (75%) who arrive to the hospi- tal alive are hemodynamically stable, but only 10% survive more than 6 h. Patients arriving to the hospital alive most frequently present with injury at the aortic isthmus where periadventitial tissue seems to provide some degree of protection against free rupture. The majority of patients with BAI have an associated closed head injury, multiple rib fractures, lung contusions, or orthopedic injuries.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “The SVS AI grading system is based on the following criteria: (grade I) intimal tear; (grade II) intramural hematoma; (grade III) pseudoaneurysm; (grade IV) rupture. Under this system, grade I-II are considered mild and grade III-IV are considered severe. In our investigation, we created criteria for radiographic severe injury and used this as a binary variable (severe versus the others) rather than creating a full grading system.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “Radiographically severe injuries were those meeting any of the following criteria: total/partial aortic transection, active contrast extravasation, or the association of 2 of more of the following: contained contrast extravasation > 10 mm, periaortic hematoma and/or mediastinal hematoma thicker than 10 mm, or significant left pleural effusion. We evaluated multiple inju- ries where a pseudoaneurysm was found in isolation, without significant associated hematoma or extravasation, which did not meet criteria for RSI. Thus, many injuries that would be graded III by the SVS system were not included in our RSI classification since they did not meet our selection criteria.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “Acute aortic injuries are not common in the setting of severe blunt trauma, but lead to significant morbidity and mortality. High- quality MDCT with 2D MPRs and 3D rendering are essential to identify aortic trauma and distinguish anatomic variants and other forms of aortic pathology from an acute injury. Misinterpretation of mimics of acute aortic injury can lead to unnecessary arteriography and thoracic surgery. Since most traumatic injuries occur in the distal arch, radiologists must be cognizant of the range of appearances of variants related to the ductus diverticulum. Cinematic rendering (CR) is a new 3D post-processing tool that provides even greater anatomic detail than traditional volume rendering. In this case series, CR is used to impart to radiologists a better understanding of various anatomic configurations that can be seen with a ductus diverticulum.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • "Among these is the ductus diverticulum—a remnant of the ductus arteriosus that arises from the lesser curvature of the aortic arch, which can be mistaken for a traumatic aortic pseudoaneurysm, dissection, or incomplete rupture. The distal aortic arch, and in particular the undersurface, is the most common location for acute traumatic aortic injury. Differentiation of a ductus diverticulum from an aortic injury can be difficult, but it is of paramount importance in order to spare patients the morbidity of unnecessary thoracic surgery. This becomes more challenging in the setting of other thoracic traumatic injury, especially mediastinal hematoma, as demonstrated in this case report.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • "Postprocessing with 2D multiplanar reconstructions and 3D rendering has become standard of care in CT angiography. One of the advantages of volume rendering over maximum intensity projection is the ability to convey 3D anatomic relationships. For complex anatomic configurations like the thoracic aorta and pulmonary arteries, the lighting model in cinematic rendering adds even greater anatomic detail, as demonstrated by these cases. The potential added value of cinematic rendering in accurately identifying and characterizing vascular pathology will require further study as this new 3D visualization methodology becomes more widely available.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • “A number of artifacts can mimic a traumatic injury of the thoracic aorta. The classic example is that of the cardiac pulsation artifact, especially in the ascending aorta. If there is any doubt, CT angiography with ECG-gating or a transoesophageal echocardiogram will allow this pathology to be excluded in stable patient. Nonetheless, there remain a number of pitfalls that require particular attention.”
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • “Nonetheless, there remain a number of pitfalls that require particular attention:
    •pseudo ruptures: on lateral aortic imaging there is an accumulation of contrast material in a wall crevice, andthis finding varies in terms of whether or not it points to a pathology. It is usually a congenital abnormality, such as a dilation at the aortic insertion into an arterial canal, known as ductus diverticulum. Sometimes these images correspond to acquired conditions, such as aneurysms or simple or complicated plaques of atherosclerosis.”
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • • mediastinal haematoma of venous origin: not all mediastinal bleeding corresponds to aortic injury. The literature describes trauma injuries to the great veins like the supe-rior vena cava. These injuries are rare but they can be life-threatening;
    • mediastinal haematoma secondary to an extra-aortic injury. It is important to know how to detect abnormalitiesof the supra-aortic vessels, possibly using 3D reconstruct-ions. These dangerous lesions are a therapeutic challenge.They are often associated with aortic injuries although they can sometimes be isolated.
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
Vascular

  • "Rapid deceleration is the universal mechanism of this injury. Most commonly, there are multiple other life- threatening injuries present with less than 20% having this as an isolated injury making the diagnosis and initial next steps challenging. BTAI is defined as a tear in the aorta that is a result of a combination of shear and stretch forces, rapid deceleration, increased intravascular pressure and compression of the aorta between the anterior chest wall and vertebrae.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “Up to 80% of patients presenting with blunt thoracic aortic injury(BTAI) die before hospitalization, and in the remaining survivors, in- hospital mortality is as high as 46%. While this is a potentially lethal injury, it is rare and accounts for 1.5% of thoracic trauma.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Injury can occur along the entire length of the aorta, essentially from the ascending aorta to the iliac bifurcation, although the injury typically occurs areas of aortic tethering, notably the aortic isthmus.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “Blunt thoracic aortic trauma is associated with other major entities of chest trauma, including, but not limited to, sternal fracture, 1st/2nd rib fractures, clavicle and/or scapular fractures, pneumothoraces, hemothoraces, flail chest, pulmonary contusions, diaphragm injury, tracheobronchial disruption and esophageal injuries; these should raise suspicion for BTAI.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Injuries are assigned one of 4 grades based on CTA imaging: grade 1 (intimal tear), grade II (intramural hematoma), grade III (pseudoaneurysm) and grade IV (rupture). Currently, the recommendation is to proceed with surgical repair of Grade II-IV injuries [20]. For grade I injuries, it is well established that no intervention is necessary as these tend to resolve on their own with conservative management. Grade II injures do fall into a “gray zone” between medical management and operative intervention although more recent studies do document that nonoperative is safe with close follow up.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular approaches have slowly replaced open surgical repair for the management of this pathology. Clearly, such patients that present with blunt thoracic injury should be relegated to centers that specialize in the polytrauma patient as it is their concurrent injuries that are the focus of their critical care.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • “The CT findings of TAI can be divided into direct signs of injury and indirect or associated findings. Direct findings of aortic injury include intramural hematoma, intimal flap and pseudoaneurysm. Injuries that only involve the intima, classified as minimal aortic injuries, should only have direct findings of TAI. Minimal aortic injuries can present with an intimal flap, intraluminal aortic thrombus or intramural hematoma. With the improvement in technology allowing thinner CT slice thickness minimal aortic injuries are being diagnosed more frequently.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "Ductal remnants, a diverticulum or small bump, are normal remnants of the embryologic ductus arteriosus. This normal variant can simulate injury and can be very perplexing for the inexperienced or unaware radiologist. The ductal diverticulum is a remnant of the closed or partially closed ductus arteriosus which connects the pulmonary artery to the aorta in fetal circulation. Ductal remnants are located at the inferior surface of the aortic arch near the aortic isthmus which leads to their confusion with TAIs. Ductal remnants are typically smooth walled and have obtuse margins that are continuous with the aortic wall and are often calcified. The presence of calcification can be very helpful in distinguishing a ductal remnant from a TAI with the presence of calcification favoring a benign ductal remnant.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "Mediastinal hematomas can be due to injury to other structures including the pulmonary artery, great vessels or mediastinal veins, or even fractures of vertebral bodies. Presence of a mediastinal hematoma should prompt a careful search for an aortic, pulmonary artery or great vessel injury. In the absence of an identified arterial injury the hematoma is likely venous. A preserved fat plane around the aorta or hematoma centered away from the aorta is less likely to be associated with aortic injury and more likely to be venous.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • "The best way to distinguish a true aortic root injury from motion artifact is to repeat thoracic imaging with ECG gating; and echocardiography can be a reasonable alternative. The difference between a study done without and with ECG gating is illustrated in. In our institution all of the chest CT done as part of a trauma survey are acquired without ECG gating. Since the majority of TAIs are at the aortic isthmus, which is typically well seen on non-gated studies, we feel the additional radiation exposure and time required for setup and acquisition of an ECG gated study is not necessary for every patient.”
    Traumatic aortic injury: CT findings, mimics, and therapeutic options  
    Ethany L. Cullen et al.
    Cardiovasc Diagn Ther 2014;4(3):238-244 
  • “Blunt aortic injuries (BAI) represent the second leading cause of death from motor vehicle crashes accounting for 15% of all motor vehicle accident-associated deaths. Death occurs at the scene of the accident in 70–90% of the cases. According to historical case series, the majority of the patients with BAI (75%) who arrive to the hospi- tal alive are hemodynamically stable, but only 10% survive more than 6 h. Patients arriving to the hospital alive most frequently present with injury at the aortic isthmus where periadventitial tissue seems to provide some degree of protection against free rupture. The majority of patients with BAI have an associated closed head injury, multiple rib fractures, lung contusions, or orthopedic injuries.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “The SVS AI grading system is based on the following criteria: (grade I) intimal tear; (grade II) intramural hematoma; (grade III) pseudoaneurysm; (grade IV) rupture. Under this system, grade I-II are considered mild and grade III-IV are considered severe. In our investigation, we created criteria for radiographic severe injury and used this as a binary variable (severe versus the others) rather than creating a full grading system.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “Radiographically severe injuries were those meeting any of the following criteria: total/partial aortic transection, active contrast extravasation, or the association of 2 of more of the following: contained contrast extravasation > 10 mm, periaortic hematoma and/or mediastinal hematoma thicker than 10 mm, or significant left pleural effusion. We evaluated multiple inju- ries where a pseudoaneurysm was found in isolation, without significant associated hematoma or extravasation, which did not meet criteria for RSI. Thus, many injuries that would be graded III by the SVS system were not included in our RSI classification since they did not meet our selection criteria.”
    Blunt aortic injuries in the new era: radiologic findings and polytrauma risk assessment dictates management strategy  
    Rachel Elizabeth Payne et al.
    European Journal of Trauma and Emergency Surgery (2019) 45:951–957
  • “Acute aortic injuries are not common in the setting of severe blunt trauma, but lead to significant morbidity and mortality. High- quality MDCT with 2D MPRs and 3D rendering are essential to identify aortic trauma and distinguish anatomic variants and other forms of aortic pathology from an acute injury. Misinterpretation of mimics of acute aortic injury can lead to unnecessary arteriography and thoracic surgery. Since most traumatic injuries occur in the distal arch, radiologists must be cognizant of the range of appearances of variants related to the ductus diverticulum. Cinematic rendering (CR) is a new 3D post-processing tool that provides even greater anatomic detail than traditional volume rendering. In this case series, CR is used to impart to radiologists a better understanding of various anatomic configurations that can be seen with a ductus diverticulum.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • "Among these is the ductus diverticulum—a remnant of the ductus arteriosus that arises from the lesser curvature of the aortic arch, which can be mistaken for a traumatic aortic pseudoaneurysm, dissection, or incomplete rupture. The distal aortic arch, and in particular the undersurface, is the most common location for acute traumatic aortic injury. Differentiation of a ductus diverticulum from an aortic injury can be difficult, but it is of paramount importance in order to spare patients the morbidity of unnecessary thoracic surgery. This becomes more challenging in the setting of other thoracic traumatic injury, especially mediastinal hematoma, as demonstrated in this case report.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 

  • MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 

  • MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important.
    Main body: Blunt thoracic aortic injury may be fatal if not diagnosed and treated expeditiously. Endovascular options allow safe and effective management of these dangerous injuries. This paper describes the overview of blunt thoracic aortic trauma, the epidemiology, presentation, diagnosis, and treatment options with a focus on endovascular management.  
    Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.  
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62 
  • Background: Blunt thoracic aortic injury, a life-threatening concern, remains the second most common cause of mortality among all non-penetrating traumatic injuries, second only to intracranial hemorrhage. Kinetic forces from the rapid deceleration are the impetus for the injury mechanism and are graded accordingly. Given the prevalence of trauma as a public health problem, contemporary management considerations are important. and treatment options with a focus on endovascular management.
    Conclusion: Blunt thoracic aortic injury requires a high index of suspicion based on mechanism of injury in the trauma population. Endovascular options have become the mainstay of blunt thoracic aortic injury treatment whenever feasible with satisfactory results and long-term outcomes.  
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62 
  • “Up to 80% of patients presenting with blunt thoracic aortic injury(BTAI) die before hospitalization, and in the remaining survivors, in- hospital mortality is as high as 46%. While this is a potentially lethal injury, it is rare and accounts for 1.5% of thoracic trauma.”
    Blunt thoracic aortic injury – concepts and management  
    Nicolas J. Mouawad et al.
    Journal of Cardiothoracic Surgery (2020) 15:62
  • "Postprocessing with 2D multiplanar reconstructions and 3D rendering has become standard of care in CT angiography. One of the advantages of volume rendering over maximum intensity projection is the ability to convey 3D anatomic relationships. For complex anatomic configurations like the thoracic aorta and pulmonary arteries, the lighting model in cinematic rendering adds even greater anatomic detail, as demonstrated by these cases. The potential added value of cinematic rendering in accurately identifying and characterizing vascular pathology will require further study as this new 3D visualization methodology becomes more widely available.”
    MDCT of ductus diverticulum: 3D cinematic rendering to enhance understanding of anatomic configuration and avoid misinterpretation as traumatic aortic injury  
    Steven P. Rowe & Pamela T. Johnson & Elliot K. Fishman
    Emergency Radiology (2018) 25:209–213 
  • “A number of artifacts can mimic a traumatic injury of the thoracic aorta. The classic example is that of the cardiac pulsation artifact, especially in the ascending aorta. If there is any doubt, CT angiography with ECG-gating or a transoesophageal echocardiogram will allow this pathology to be excluded in stable patient. Nonetheless, there remain a number of pitfalls that require particular attention.”
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • “Nonetheless, there remain a number of pitfalls that require particular attention:
    •pseudo ruptures: on lateral aortic imaging there is an accumulation of contrast material in a wall crevice, andthis finding varies in terms of whether or not it points to a pathology. It is usually a congenital abnormality, such as a dilation at the aortic insertion into an arterial canal, known as ductus diverticulum. Sometimes these images correspond to acquired conditions, such as aneurysms or simple or complicated plaques of atherosclerosis.”
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • • mediastinal haematoma of venous origin: not all mediastinal bleeding corresponds to aortic injury. The literature describes trauma injuries to the great veins like the supe-rior vena cava. These injuries are rare but they can be life-threatening;
    • mediastinal haematoma secondary to an extra-aortic injury. It is important to know how to detect abnormalitiesof the supra-aortic vessels, possibly using 3D reconstruct-ions. These dangerous lesions are a therapeutic challenge.They are often associated with aortic injuries although they can sometimes be isolated.
    Traumatic injuries of the thoracic aorta:The role of imaging in diagnosis and treatment
    F.Z. Mokranea et al.
    Diagnostic and Interventional Imaging (2015) 96, 693—706
  • “Angiosarcoma is an extremely rare tumor but is the most common primary non-hematolymphoid malignancy. It is an extremely aggressive neoplasm with widespread metastasis and splenic rupture common presenting manifestations. The most common CT finding is a patient with splenomegaly (60%) containing a large heterogenous solid mass or masses that nearly replace the spleen.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • “Splenic artery aneurysms are the most frequent of visceral artery aneurysms. Splenic artery aneurysms may be intra or extra-splenic and most of the cases are calcified. If it measures more than 2.0 cm, there is high risk of rupture (76% fatal), and are often treated.Women with more than two pregnancies have high predisposition to aneurysm rupture and are often treated more aggressively.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • Interruption of the inferior vena cava: facts
    - Interruption of the inferior vena cava (IVC) with azygos continuation is a rare congenital anomaly, in which the IVC is interrupted below the hepatic vein and venous return beyond this point is restored by the dilated azygos and hemiazygos veins draining into the superior vena cava.
    - this congenital anomaly could be isolated, but often it is part of more complex syndrome including for example cardiac malformations, asplenia, and polysplenia syndrome. Interruption of the IVC with azygos continuation is the second most common abnormality associated with polysplenia syndrome 
  • “The polysplenic syndrome is defined by the presence of multiple spleens, usually numbering between two and six. In contrast to accessory spleens, the spleens are of uniform size. Accessory spleens usually measure between 1 and 2 cm and are not considered as a form of the polysplenic syndrome. Splenosis, an acquired rather than congenital condition that arises in the context of traumatic splenic rupture, can be ruled out by patient history.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396,
  • ”Splenosis typically consists of multiple small implants of splenic tissue; it can mimic peritoneal carcinomatosis or endometriosis depending on the clinical context.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396,
  • "The syndrome of polysplenia is often accompanied by a variable spectrum of visceral and vascular developmental anomalies. It is rarely diagnosed in adults. While it is estimated that 2.5/100,000 infants are born with this anomally, fewer than 5% are still alive at five years of age due to the associated severe cardiac anomalies.The syndrome is associated with multiple congenital malformations that may involve the solid organs and digestive tube of the abdominal cavity, the heart, or the great vessels. The diagnosis is often made during surgical exploration for an associated cardiac or digestive anomaly. Among the most common vascular anomalies are agenesis of the suprarenal inferior vena cava with persistent continuity of the azygos vein, and pre-duodenal position of the portal vein. Biliary atresia is found in nearly 50% of cases, common mesentery in more than 75% of cases, and an abbreviated or annular pancreas in 85–90% of cases.”
    Polysplenia syndrome
    B. De La Villeon et al.
    Journal of Visceral Surgery,Volume 148, Issue 5,2011, Pages e395-e396
  • "Anomalies include asplenia, the congenital absence of the spleen. This can be isolated or part of a clinical sequela of a broader syndrome such as Ivermark syndrome, a heterotaxy syndrome occurring in 1 in 10,000 to 40,000 cases. CT will show lack of spleen and Tc-99 red blood cell scan will show lack of uptake.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • "Accessory spleen is a frequent congenital variation (20% of autopsy) due to failure in coalescence of mesodermal buds in the dorsal mesogastrium.The accessory spleen is supplied by the splenic artery and most are located near the splenic hilum. On pre- and post-contrast imaging, this enhances similarly to splenic parenchyma. This entity is important to recognize because it could be responsible for the recurrence of hematologic disorders after splenectomy.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
  • "Splenosis in an acquired condition that occurs after splenectomy or splenic rupture is represented by seeding or implantation of splenic cells in any location, frequently simulating tumors. On pre- and post-contrast, imaging, splenosis appears similar to the normal spleen. When ectopic splenic tissue or splenosis is in the differential for a mass around the splenic hilum or splenectomy bed, a technetium tagged heat-damaged red blood cell scan is a nuclear medicine examination that can delineate ectopic splenic tissue. Splenosis is usually managed conservatively and history is key to help differentiate it from other lesions.”
    MDCT Findings of Splenic Pathology
    Sangster GP et al.
    Current Problems in Diagnostic Radiology 2021 (in press)
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