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

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

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Adrenal

  • Bilateral Adrenal Masses: Pheochromocytoma
    - Approximately 10% of pheochromocytomas are extra-adrenal, bilateral, multifocal, malignant, found in children, or associated with a hereditary or familial syndrome. Pediatric pheochromocytomas account for 10% of all pheochromocytomas; these are characterized by a slight male predominance and are less likely malignant than adult tumors. Approximately 30% of pediatric pheochromocytomas are bilateral, extra-adrenal, multiple, or familial.
  • Pheochromocytoma:  Familial Data 
    - Approximately 10% of pheochromocytomas are familial, associated with neuroectodermal disorders (von Hippel-Lindau disease, von Recklinghausen's disease, tuberous sclerosis, Sturge-Weber syndrome or Carney's syndrome) or as a part of hereditary multiple endocrine neoplasia (MEN) 2A and 2B. 
  • Pheochromocytoma:  Familial Data 
    - In MEN-2, bilateral adrenal medullary hyperplesia (diffuse or nodular) is almost always present and precedes pheochromocytoma, which develops in 30–50% of patients. Pheochromocytomas are usually multicentric and bilateral in up to 50–80% of cases with long term follow-up. They are rarely extra-adrenal or malignant.
  • Pheochromocytoma:  Familial Data 
    - Pheochromocytomas associated with neuroectodermal disorders are most common in von Hippel-Lindau disease, occurring in approximately 25% of patients. They are often bilateral and rarely extra-adrenal except in Carney's syndrome, which is associated with functioning extra-adrenal paraganglioma. All patients with “sporadic” pheochromocytoma should be screened for MEN-2 and van Hippel-Lindau disease.
  • “Cystic appearance was present in 12/22 (55%, 95% CI 32-76%) pheochromocytomas (mean size 5.3 cm), 15/34 (44%, 95% CI 27-62%) malignant masses (mean size 5.8 cm), and 2/36 (5.6%, 95% CI 0.7-9%) adenomas (mean size 3.2 cm). Sensitivity and specificity of cystic appearance for distinguishing pheochromocytoma or malignant masses from adenomas were 48.2% (95% CI 34.7-62.0%) and 94.4% (95% CI 81.3-99.3%), respectively. Cystic appearance was a significant predictor of tumor type (p = 0.015) even after controlling for tumor size. Reader agreement for cystic appearance was almost perfect with a kappa of 0.85.”
    Accuracy of focal cystic appearance within adrenal nodules on contrast-enhanced CT to distinguish pheochromocytoma and malignant adrenal tumors from adenomas.  
    Corwin MT et al.  
    Abdom Radiol (NY). 2021 Jan 8. doi: 10.1007/s00261-020-02925-5. 
  • “An indeterminate adrenal lesion that enhances greater than 130 HU on multidetector CT cannot be assumed to be an adenoma. Hypervascular pheochromocytoma (>130 HU) mimics adenoma washout pattern; absolute venous phase enhancement level must be considered.”
    Adrenal Adenoma and Pheochromocytoma: Comparison of Multidetector CT Venous Enhancement Levels and Washout Characteristics.  
    Northcutt BG, Trakhtenbroit MA, Gomez EN, Fishman EK, Johnson PT.
    J Comput Assist Tomogr. 2016 Mar-Apr;40(2):194-200.
  • Objective: To evaluate the proportion of pheochromocytomas meeting the criteria for adenoma on adrenal washout CT and the diagnostic performance of adrenal washout CT for differentiating adenoma from pheochromocytoma.
    Conclusions: There was a non-negligible proportion of pheochromocytomas meeting the criteria for adenoma on adrenal washout CT. Although overall diagnostic performance was excellent for differentiating adenoma from pheochromocytoma, specificity was relatively low.
    Pheochromocytoma as a frequent false-positive in adrenal washout CT: A systematic review and meta-analysis.
    Woo S, Suh CH, Kim SY, Cho JY, Kim SH.  
    Eur Radiol. 2018 Mar;28(3):1027-1036.
  • Key points:  
    • Non-negligible proportion of pheochromocytomas can be mistaken for adenoma.  
    • Adrenal washout CT showed good sensitivity (97%) but relatively low specificity (67%).  
    • Findings other than washout percentage should be used when diagnosing pheochromocytomas.
    Pheochromocytoma as a frequent false-positive in adrenal washout CT: A systematic review and meta-analysis.
    Woo S, Suh CH, Kim SY, Cho JY, Kim SH.  
    Eur Radiol. 2018 Mar;28(3):1027-1036.
  • “The majority of LATs were still benign, but they had a higher probability to be malignant. Benign LATs made up 68.13% of all cases, mainly adrenal cysts (19.52%), pheochromocytoma (18.73%), benign adenoma (16.73%), and myelolipoma (7.17%). Malignant LATs accounted for 28.69% of cases, mainly including adrenocortical carcinoma (8.76%) and metastases (17.13%). Laparoscopic surgery was found to involve less trauma than open surgery. It was also safer and postoperative recovery was faster, but it had drawbacks and could not completely replace open surgery. CT features had obvious specificity for the diagnosis of benign and malignant tumors.”
    Clinical analysis of adrenal lesions larger than 5 cm in diameter (an analysis of 251 cases).  
    Zhang Z et al.  
    World J Surg Oncol. 2019 Dec 16;17(1):220.
  • "CT features had obvious specificity for the diagnosis of benign and malignant tumors. For example, benign adenomas had a smaller pre-contrast (< 10 Hu) whereas malignant adrenal tumors had, on the contrary, higher attenuation. Regarding adrenal malignant carcinoma, adrenal primary malignant tumors showed a better prognosis than adrenal metastases (mean survival of 19.17 months vs 9.49 months). Primary adrenal cortical carcinoma without metastasis had a better prognosis than primary adrenal cortical carcinoma metastasis (mean survival of 23.71 months vs 12.75 months), and adrenal solitary metastasis had a better prognosis than general multiple metastatic carcinoma (mean survival of 14.95 months vs 5.17 months).”
    Clinical analysis of adrenal lesions larger than 5 cm in diameter (an analysis of 251 cases).  
    Zhang Z et al.  
    World J Surg Oncol. 2019 Dec 16;17(1):220.
  • “Although in general PCC/PGL are rare tumors, NF1 is a common condition (prevalence of 1:3000 live births), and an estimated 5–7% of patients with NF1 will develop PCC/PGL in their lifetime. NF1 has a high rate of de novo mutations (~ 50%), is inherited in autosomal dominant fashion, and has a variable clinical presentation. The diagnosis of NF1 is made clinically in those who meet at least two of the following criteria: 6 or more café-au-lait macules, axillary or inguinal freckling, 2 or more neurofibromas or 1 plexiform neurofibroma, 2 or more Lisch nodules, an optic glioma, sphenoid or tibial bone dysplasia, or a first-degree relative with NF1.”
    Pheochromocytoma and Paraganglioma in Neurofibromatosis type 1: frequent surgeries and cardiovascular crises indicate the need for screening.  
    Petr, E.J., Else, T.  
    Clin Diabetes Endocrinol 4, 15 (2018).
  • "Pheochromocytomas (PCC) and Paragangliomas (PGL) are rare endocrine tumors, occurring with an incidence of 0.8 per 100,000. Most of these tumors are benign, rather than malignant, however they can cause significant morbidity and mortality via catecholamine excess and resultant cardiovascular crises. A significant percentage (~ 30%) of those affected with PCC/PGL tumors harbor a germline mutation that predisposes them both to the development of PCC/PGL and also to other tumors unique to each particular inherited syndrome.”
    Pheochromocytoma and Paraganglioma in Neurofibromatosis type 1: frequent surgeries and cardiovascular crises indicate the need for screening.  
    Petr, E.J., Else, T.  
    Clin Diabetes Endocrinol 4, 15 (2018).
  • “The most common known hereditary tumor syndromes that increase risk for PCC/PGL are Hereditary Paraganglioma Syndrome (SDHx), Neurofibromatosis Type 1 (NF1), von Hippel Lindau disease (VHL), Multiple Endocrine Neoplasia type 2 (MEN2, RET), TMEM127- and MAX-related hereditary pheochromocytoma, and Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC, FH).”
    Pheochromocytoma and Paraganglioma in Neurofibromatosis type 1: frequent surgeries and cardiovascular crises indicate the need for screening.  
    Petr, E.J., Else, T.  
    Clin Diabetes Endocrinol 4, 15 (2018).
  • “In summary, NF1-associated PCC/PGL presented at a similar age as reported for sporadic cases of PCC/PGL. The majority of NF1-associated PCC/PGL were benign unilateral adrenal tumors, which were biochemically active and positive on MIBG scans. Most patients had hypertension or tachycardia or both at the time of diagnosis. Although almost half of the PCC/PGL in this cohort (n = 8) were discovered incidentally on imaging, upon further investigation three of these patients had suggestive symptoms of PCC/PGL (tachycardia, palpitations, HTN urgency) and one had a preexisting adrenal nodule that had not been evaluated.”
    Pheochromocytoma and Paraganglioma in Neurofibromatosis type 1: frequent surgeries and cardiovascular crises indicate the need for screening.  
    Petr, E.J., Else, T.  
    Clin Diabetes Endocrinol 4, 15 (2018).
  • “In summary, undiagnosed NF1-associated PCC/PGL poses a dangerous risk to patients, including cardiovascular crises such as labile intra-operative blood pressures, pregnancy and delivery complications, and severe complications including MI and cardiac arrest. Most NF1-associated PCC/PGL are detectable by biochemical evaluation. Therefore, we suggest consideration of screening adults with NF1 for PCC/PGL with plasma or urine free fractionated metanephrines every 1–2 years starting at age 18, especially in any NF1 patient with hypertension or tachycardia, and most importantly prior to any surgical procedures and pregnancy or delivery as these are times of increased risk for cardiovascular crisis. This approach has the potential to reduce the PCC/PGL-associated morbidity and mortality in the population of patients with NF1.”
    Pheochromocytoma and Paraganglioma in Neurofibromatosis type 1: frequent surgeries and cardiovascular crises indicate the need for screening.  
    Petr, E.J., Else, T.  
    Clin Diabetes Endocrinol 4, 15 (2018).
  • Bilateral Adrenal Masses: Differential Dx
    - Adenoma
    - Pheochromocytoma
    - Metastases
    - Hematoma
    - Infection (TB)
Chest

  • Since 1986, The Carter Center has led the international campaign to eradicate Guinea worm disease, working closely with ministries of health and local communities, the U.S. Centers for Disease Control and Prevention, the World Health Organization, UNICEF, and many others. Guinea worm disease could become the second human disease in history, after smallpox, to be eradicated. It would be the first parasitic disease to be eradicated and the first disease to be eradicated without the use of a vaccine or medicine. 
  • Guinea worm disease (dracunculiasis) is a parasitic infection caused by the nematode roundworm parasite Dracunculus medinensis. It is contracted when people consume water from stagnant sources contaminated with Guinea worm larvae. Inside a human's abdomen, Guinea worm larvae mate and female worms mature and grow. After about a year of incubation, the female Guinea worm, one meter long, creates an agonizingly painful lesion on the skin and slowly emerges from the body. Guinea worm sufferers may try to seek relief from the burning sensation caused by the emerging worm and immerse their limbs in water sources, but this contact with water stimulates the emerging worm to release its larvae into the water and begin the cycle of infection all over again.
  • How Widespread is the Disease? 
    - In 1986, the disease afflicted an estimated 3.5 million people a year in 21 countries in Africa and Asia. Today, thanks to the work of The Carter Center and its partners — including the countries themselves — the incidence of Guinea worm has been reduced by more than 99.99 percent to 27 provisional* cases in 2020.
    - The Carter Center works to eradicate Guinea worm in five countries affected by the disease: South Sudan, Mali, Chad, Ethiopia, and Angola.
Colon

  • “FAP is the most common GI polyposis syndrome, characterized by the presence of more than 100 synchronous colorectal adenomas and a 100% lifetime risk of colorectal cancer. FAP is an autosomal dominant condition caused by germline mutations in the adenomatous polyposis coli (APC) gene on chromosome 5q21, although one-third of new cases are due to de novo mutations. APC is a tumor suppressor gene that functions in the Wnt pathway, and its loss leads to accumulation of b-catenin oncoprotein, with subsequent uncontrolled cellular proliferation.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • "Gastric fundic gland hamartomatous and hyperplastic polyps and duodenal adenomas are the most common extra- colonic GI findings in FAP; duodenal/periampul- lary cancer (4%–10%) is the most common cause of death in patients with FAP who have undergone prophylactic colectomy. Gastric carcinoma and small bowel polyps are not common in patients with FAP.”  
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • “Desmoids in patients with FAP have a predi- lection for surgical sites and mostly develop after prophylactic colectomy .The small bowel mesentery and musculoaponeurotic structures of the abdominal wall near prior surgical sites are the two most common locations for desmoids in FAP. Desmoids are locally aggressive and can lead to long-term and at times devastating complications, including bowel obstruction, mesenteric ischemia, ureteric obstruction, fistula, and abscess formation . Desmoids are the cause of death in up to 10% of patients with FAP.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • “JPS is an autosomal dominant condition characterized by the presence of multiple juvenile polyps in the colon and rectum (98%), the stomach (14%), and less commonly the duodenum, jejunum, and ileum. Up to 70% of colonic polyps develop in the proximal colon.The term juvenile refers to the histologic type of the polyps, not the age of clinical diagnosis or the age of onset of polyps.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • "Large polyps are seen as masslike lesions at CT and can prolapse and cause obstruction.The antropyloric region is the most common site for gastric polyps; rarely, diffuse gastric polyposis can be seen in the absence of colonic polyps and can be identified at upper GI contrast material study. Smaller gastric polyps can be seen as multiple small nodular masses carpeting the stomach or diffuse wall thickening at CT or MRI and can mimic Ménétrier disease or diffuse linitis plastica of diffuse gastric cancer.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • “PJS is characterized by histologically distinc- tive hamartomatous polyps of the GI tract, most frequently in the small bowel (96%), colorectum (25%–50%), and stomach (25%), along with characteristic mucocutaneous pigmentation in the perioral area (55). PJS is an autosomal domi- nant condition due to a mutation in the STK11 tumor suppressor gene (previously called LKB1), located on chromosome 19p13, which encodes a serine-threonine kinase involved in cell cycle activities, mTOR (mammalian target of rapamy- cin) regulation, chromatin remodeling, and Wnt pathway signaling (23,55). Ninety-four percent of affected PJS families demonstrate mutations of STK11; 25% of newly diagnosed PJS cases are sporadic with de novo mutations.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
Contrast

  • Purpose: Intravenous iodinated contrast is a commonly used diagnostic aid to improve image quality on computed tomography. There exists a small risk of post-contrast acute kidney injury in patients receiving IV contrast. One of the biggest risk factors for developing PC-AKI is the presence of pre-existing renal dysfunction, making it important to measure the renal function prior to contrast administration. Point of care (POC) devices offer a quick estimation of renal function, potentially improving workflows in radiology departments.  
    Conclusion: POC devices are moderately accurate at detecting renal impairment in patients undergoing radiological investigations. They seem to be a good screening tool; however, any low eGFR values should be further examined.
    Is point of care renal function testing reliable screening pre-IV contrast administration?  
    Namit Mathur et al.
    Emergency Radiology (2021) 28:77–82 
  • “A key factor in the development of PC-AKI is the presence of pre-existing chronic kidney disease (CKD) . Hence, it is essential to estimate the patient’s renal function prior to intravenous iodinated contrast administration. CKD is classified according the patient’s eGFR. The Royal Australian and New Zealand College of Radiologists (RANZCR) iodinated contrast guidelines stratify renal function into three groups. Patients with an eGFR of less than 30 are classified as having severe renal impairment; these patients require a discussion with the referring clinician to weigh up the risks versus bene- fits of contrast administration and require periprocedural hy- dration. Additionally, patients with a rapidly changing renal function with an eGFR between 30 and 45 may also benefit from periprocedural hydration.”
    Is point of care renal function testing reliable screening pre-IV contrast administration?  
    Namit Mathur et al.
    Emergency Radiology (2021) 28:77–82 
  • “Point of care devices are moderately accurate for identification of renally impaired patients prior to intravenous contrast ad- ministration for CT examination. The results of Abbott iSTAT device show better correlation with laboratory results than the Nova StatSensor device. Within the limits of small number of high risk patients in this study, both devices seem to be accu- rate in diagnosing high-risk patients with an eGFR of less than 30. They become moderately accurate at higher eGFRs. POC devices can be implemented as a screening tool prior to IV contrast administration as both machines have low false neg- ative rates. Caution should be taken when the POC eGFR values are discordant with previously known blood test result or contradictory to the answers on the pre-iodination contrast questionnaire/screening forms.”
    Is point of care renal function testing reliable screening pre-IV contrast administration?  
    Namit Mathur et al.
    Emergency Radiology (2021) 28:77–82 
Deep Learning

  • “Pancreatic cancer remains a major health problem, and only less than 20% of patients have resectable disease at the time of initial diagnosis. Systemic chemotherapy is often used in the patients with borderline resectable, locally advanced unresectable disease and metastatic disease. CT is often used to assess for therapeutic response; however, conventional imaging including CT may not correctly reflect treatment response after chemotherapy.”
    Assessment of iodine uptake by pancreatic cancer following chemotherapy using dual-energy CT.  
    Kawamoto S, Fuld MK, Laheru D, Huang P, Fishman EK.  
    Abdom Radiol (NY). 2018;43(2):445-456. 
  • "Dual-energy (DE) CT can acquire datasets at two different photon spectra in a single CT acquisition, and permits separating materials and extract iodine by applying a material decomposition algorithm. Quantitative iodine mapping may have an added value over conventional CT imaging for monitoring the treatment effects in patients with pancreatic cancer and potentially serve as a unique biomarker for treatment response. In this pictorial essay, we will review the technique for iodine quantification of pancreatic cancer by DECT and discuss our observations of iodine quantification at baseline and after systemic chemotherapy with conventional cytotoxic agents.”
    Assessment of iodine uptake by pancreatic cancer following chemotherapy using dual-energy CT.  
    Kawamoto S, Fuld MK, Laheru D, Huang P, Fishman EK.  
    Abdom Radiol (NY). 2018;43(2):445-456. 
  • “The parameters obtained using tumor segmentation software included (1) RECIST diameter (mm), (2) tumor volume (mL), (3) mean CT number of tumor (HU) at simulated weighted-average 120-kVp images, (4) iodine uptake by tumor per volume of tissue (mg/mL), and (5) normalized tumor iodine uptake (tumor iodine uptake normalized to the reference value acquired using region of interest place in the abdominal aorta at the level of the pancreatic tumor, calculated by tumor iodine uptake [mg/dL]/abdominal aortic uptake [mg/dL]).”
  • “In conclusion, iodine uptake by pancreatic adenocarcinoma using DECT may add supplemental information for assessment of treatment response, although tumor iodine uptake by pancreatic adenocarcinoma is small, and it may be difficult to apply to each case. Normalized tumor iodine uptake might be more sensitive than iodine concentration to measure treatment response. More data are necessary to confirm these observations.”
    Assessment of iodine uptake by pancreatic cancer following chemotherapy using dual-energy CT.  
    Kawamoto S, Fuld MK, Laheru D, Huang P, Fishman EK.  
    Abdom Radiol (NY). 2018;43(2):445-456.
  • Purpose: Evaluate utility of dual energy CT iodine material density images to identify preoperatively nodal positivity in pancreatic cancer patients who underwent neoadjuvant therapy.
    Conclusion: The dual energy based minimum normalized iodine value of all nodes in the surgical field on preoperative studies has modest utility in differentiating N0 from N1/2, and generally outperformed conventional features for identifying nodal metastases.
    CT features predictive of nodal positivity at surgery in pancreatic cancer patients following neoadjuvant therapy in the setting of dual energy CT.  
    Le O, Javadi S, Bhosale PR et al.  
    Abdom Radiol (NY). 2021 Jan 20. doi: 10.1007/s00261-020-02917-5. Epub ahead of print. PMID: 33471129.
GU Misc

  • “The ever-growing prevalence of tuberculosis is a cause for concern among both developing and developed countries. Abdominal tuberculosis is the most common site of extrapulmonary tuberculosis and involves almost all of the visceral organs. Clinical presentation of abdominal tuberculosis is often non-specific. Thus, having a high index of clinical suspicion is necessary to aide early diagnosis and guide prompt initiation of appropriate treatment. In this review, we focus on the entire spectrum of abdominal tuberculosis and other diseases mimicking it with an emphasis on their imaging findings.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • "Abdominal tuberculosis may involve the lymph nodes, gastrointestinal system, peritoneum, and solid organs. It can occur as a consequence of reactivation of latent tuberculosis, ingestion of Mycobacterium tuberculosis (via infected lung secretions, unpasteurized dairy products or undercooked meats), hematogenous spread from an adjacent focus, or through infected lymphatic channels and nodes. Risk factors for developing abdominal TB include underlying medical conditions such as cirrhosis, diabetes mellitus, HIV infection, renal insufficiency, and malignancy; medical treatment with steroids and anti-tumor necrosis factor (TNF) agents; and others such as malnutrition, tobacco smoking, intravenous drug use and alcoholism.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “In general, clinical features are non-specific and may include fever, weight loss, abdominal/back pain, ascites, diarrhea, abdominal mass, bowel obstruction, and hematuria. A high index of suspicion is required to allow for early diagnosis and prompt initiation of therapy.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “Tuberculous infection and inflammation of the lymph nodes, called tuberculous lymphadenitis, is the most common presentation of abdominal TB presenting in 55–66% of cases.Tuberculous lymphadenitis occurs more commonly in females than males and immigrants from endemic countries with an age range of 30–40 years old.The cervical lymph nodes are the most commonly involved group due to its proximity to the lung parenchyma.Approximately 5.7–17.2% of cases with peripheral tuberculous lymphadenopathy also have involvement of abdominal lymph nodes. The most frequently involved abdominal group of lymph nodes are omental, mesenteric, and peripancreatic lymph nodes.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “Tuberculous lymphadenitis progresses through different stages which can be reflected on CT imaging. The first stage of lymphoid proliferation is marked by lymph node enlargement with homogenous enhancement. With disease progression, the central part of the lymph node undergoes caseous necrosis resulting in a centrally non-enhancing node with peripheral capsular rim-enhancement. Capsular degeneration results in the fusion of adjacent lymph nodes which appear as a multilocular enhancement. In the final stage, after treatment or healing, the lymph nodes undergo fibrosis, and calcifications can be seen.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • "The radiological differential for the appearance of abdominal tuberculous lymphadenitis includes malignancies such as nonseminomatous germ cell tumor, pancreatic cancer, lymphoma, and metastatic lymph nodes. In addition, fungal infections and celiac disease can also have a similar appearance.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • "Gastrointestinal (GI) TB is a rare manifestation of abdominal TB and is the sixth most common form of extrapulmonary TB. It can affect any part of the GI tract starting from the esophagus to the rectum. The three main forms of GI TB are (i) ulcerative type (60%), which is characterized by single or multiple mucosal ulcerations commonly affecting the jejunum and ileum, (ii) ulcero-hypertrophic type (30%), which is characterized by thickening and ulceration of intestinal wall, and (iii) hypertrophic type (10%), which is characterized by scarring and fibrosis commonly affecting the ileum and cecum.Complications of the three forms are similar and may include intestinal perforation, bleeding and fistula formation.Bowel obstruction may also occur as a result of mechanical obstruction secondary to stricture formation or intestinal hypertrophy.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • "Gastric involvement with TB is rare and seen in 0.4%–2% of cases generally affecting the antrum and distal body.Symptoms of gastric involvement include vague epigastric discomfort and upper GI bleeding. Nausea and vomiting may occur in the presence of gastric outlet obstruction secondary to antral narrowing. CT imaging can show the late-stage hypertrophic features of tuberculous pyloric stenosis. The presence of sinus tract and fistula is rare but suggestive of tuberculosis. The most commonly involved parts are the gastric antrum and distal body. On imaging, the hypertrophic form can show severe and diffuse wall thickening. Ulceration and fibrosis can lead to antral narrowing. Rarely, fistula and sinus tracts also occur in gastric TB.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “The ileocecal region is the most common site of involvement in GI TB seen in 80–90% of cases. An abundance of lymphoid tissue and an increased rate of absorption may predispose this site for TB involvement. The involvement of the rest of the small bowel is infrequent and usually occurs together with peritonitis. Clinical symptoms include colicky abdominal pain, weight loss and anemia, and complications due to intestinal obstruction, perforation and hemorrhage may also occur.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • "Micronodular or miliary TB appears as numerous tiny hypodense lesions on CT and is most commonly seen in patients with hematogenous spread of primary miliary pulmonary disease. These lesions may demonstrate minimal peripheral enhancement with IV contrast administration.These tiny lesions are often too small to be seen on CT, in which case the only apparent finding may be hepatosplenomegaly.In more advanced stages, the lesions undergo calcification which makes them easier to identify.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “The genitourinary (GU) tract is the second most common site for extrapulmonary tuberculosis after lymph node involvement, with a vast majority of cases (90%) occurring in developing countries.Genitourinary TB occurs more commonly in older adults and predominantly affects males.Genitourinary TB occurs more frequently in HIV-infected individuals compared to those without.The onset and progression of genitourinary TB is usually insidious, with an approximate 20-year latency period between infection and expression of genitourinary TB. Patients with GU tuberculosis start with a pulmonary focus which through hematogenous seeding leads to infection of the kidneys, prostate and epididymis; bacilluria spreading the infection to the ureter, bladder, and prostate, with subsequent spread to the ejaculatory ducts, seminal vesicles, vas deferens and epididymis.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • "The  kidneys are the most common site of GU tuberculous infection. Nearly 75% of renal TB cases have unilateral involvement. Presentation of renal TB is often non-specific – pyuria and microscopic hematuria may be found incidentally. In the early stages, edema and vasoconstriction in the renal parenchyma can lead to focal hypoperfusion on contrast-enhanced studies, giving an appearance similar to pyelonephritis.Low attenuation parenchymal tumor-like lesions without urinary tract involvement can also occur rarely.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “The collecting system is most commonly involved in renal tuberculosis. Initially, only a few calyces are involved, with calyceal deformity or papillary necrosis. Eventual healing and fibrosis lead to multiple strictures resulting in uneven caliectasis, the most common feature seen on cross-sectional imaging . The caliectasis is not always seen on excretory urography due to poor opacification due to infundibular stenosis, giving the appearance of the “phantom calyx”.Urography can also show a “moth-eaten” calyx due to erosions leading to irregular collections of pools of contrast. In healed or chronic renal TB, atrophy, progressive hydronephrosis, and calcifications can occur. This leads to changes in morphology, with the kidneys appearing to have multiple cysts. Eventually, a “putty kidney” appearance occurs when dystrophic calcifications develop in the entire kidney.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
  • “Peritoneal spread of tuberculosis the second most common presentation of abdominal TB, affecting between 31 and 58% of cases. It mainly occurs secondary to hematogenous spread from a pulmonary focus, but may also occur from lesions in adjacent organs or rupture of an infected lymph node or fallopian tubes.It equally affects both sexes and is mostly seen in the age ranges of 35–45 years old.”
    TB or not TB: A comprehensive review of imaging manifestations of abdominal tuberculosis and its mimics
    Heta Ladumor et al.
    Clinical Imaging 2021 (in press)
Musculoskeletal

  • Purpose: To determine the diagnostic performance of dual-energy computed tomography (CT) for detection of bone marrow (BM) infiltration in patients with multiple myeloma by using a virtual noncalcium (VNCa) technique.
    Results: In the visual analysis, VNCa images had an overall sensitivity of 91.3% (21 of 23), specificity of 90.9% (10 of 11), accuracy of 91.2% (31 of 34), positive predictive value of 95.5% (21 of 22), and a negative predictive value of 83.3% (10 of 12). ROI-based analysis of VNCa CT numbers showed a significant difference between infiltrated and normal BM (P < .001). Receiver operating characteristic analysis revealed an area under the curve of 0.978.
    Conclusion: Visual and ROI-based analyses of dual-energy VNCa images had excellent diagnostic performance for assessing BM infiltration in patients with multiple myeloma with precision comparable to that of MR imaging.
    Multiple Myeloma and Dual-Energy CT: Diagnostic Accuracy of Virtual Noncalcium Technique for Detection of Bone Marrow Infiltration of the Spine and Pelvis
    Aleksander Kosmala et al.
    Radiology 2018; 286:205–213
Pancreas

  • “Pancreatic cancer remains a major health problem, and only less than 20% of patients have resectable disease at the time of initial diagnosis. Systemic chemotherapy is often used in the patients with borderline resectable, locally advanced unresectable disease and metastatic disease. CT is often used to assess for therapeutic response; however, conventional imaging including CT may not correctly reflect treatment response after chemotherapy.”
    Assessment of iodine uptake by pancreatic cancer following chemotherapy using dual-energy CT.  
    Kawamoto S, Fuld MK, Laheru D, Huang P, Fishman EK.  
    Abdom Radiol (NY). 2018;43(2):445-456. 
  • "Dual-energy (DE) CT can acquire datasets at two different photon spectra in a single CT acquisition, and permits separating materials and extract iodine by applying a material decomposition algorithm. Quantitative iodine mapping may have an added value over conventional CT imaging for monitoring the treatment effects in patients with pancreatic cancer and potentially serve as a unique biomarker for treatment response. In this pictorial essay, we will review the technique for iodine quantification of pancreatic cancer by DECT and discuss our observations of iodine quantification at baseline and after systemic chemotherapy with conventional cytotoxic agents.”
    Assessment of iodine uptake by pancreatic cancer following chemotherapy using dual-energy CT.  
    Kawamoto S, Fuld MK, Laheru D, Huang P, Fishman EK.  
    Abdom Radiol (NY). 2018;43(2):445-456. 
  • “The parameters obtained using tumor segmentation software included (1) RECIST diameter (mm), (2) tumor volume (mL), (3) mean CT number of tumor (HU) at simulated weighted-average 120-kVp images, (4) iodine uptake by tumor per volume of tissue (mg/mL), and (5) normalized tumor iodine uptake (tumor iodine uptake normalized to the reference value acquired using region of interest place in the abdominal aorta at the level of the pancreatic tumor, calculated by tumor iodine uptake [mg/dL]/abdominal aortic uptake [mg/dL]).”
  • “In conclusion, iodine uptake by pancreatic adenocarcinoma using DECT may add supplemental information for assessment of treatment response, although tumor iodine uptake by pancreatic adenocarcinoma is small, and it may be difficult to apply to each case. Normalized tumor iodine uptake might be more sensitive than iodine concentration to measure treatment response. More data are necessary to confirm these observations.”
    Assessment of iodine uptake by pancreatic cancer following chemotherapy using dual-energy CT.  
    Kawamoto S, Fuld MK, Laheru D, Huang P, Fishman EK.  
    Abdom Radiol (NY). 2018;43(2):445-456.
  • Purpose: Evaluate utility of dual energy CT iodine material density images to identify preoperatively nodal positivity in pancreatic cancer patients who underwent neoadjuvant therapy.
    Conclusion: The dual energy based minimum normalized iodine value of all nodes in the surgical field on preoperative studies has modest utility in differentiating N0 from N1/2, and generally outperformed conventional features for identifying nodal metastases.
    CT features predictive of nodal positivity at surgery in pancreatic cancer patients following neoadjuvant therapy in the setting of dual energy CT.  
    Le O, Javadi S, Bhosale PR et al.  
    Abdom Radiol (NY). 2021 Jan 20. doi: 10.1007/s00261-020-02917-5. Epub ahead of print. PMID: 33471129.
Practice Management

  • “COVID led to greater “bunkering” of radiologists, working behind closed doors, to avoid the risk of infection and consequent depletion of available staff numbers (“on-site” distancing). Off-site teleradiological reporting also increased. Many of us moved rapidly from a situation where we had daily face-to-face contact with referrers and colleagues, to one where our only communication with others was over the telephone. This made sense in the early phase of the pandemic; we needed to ensure the capacity of radiology departments to continue to function, and unnecessarily risky behaviour of key workers had to be curtailed. Furthermore, the use of online capabilities permitted maintenance of multidisciplinary conferences during the pandemic, preserving standards of care. But, for the reasons given above, we should not allow this way of working to become the norm. The COVID pandemic is not normal life; medical practice mandated by it should equally not become the norm, beyond what is necessary in the (hopefully) short term.”
    The vanishing radiologist—an unseen danger, and a danger of being unseen
    Adrian P. Brady
    European Radiology (in press)
  • "The  notion of working in peaceful isolation, spending a given number of hours daily in front of a workstation, producing meaningful and valuable output before packing up and going home, can be attractive. In some circumstances, we may be more productive(if productivity can be counted in reports generated) in this type of environment. After all, we do not need much more than regular coffee and a dark room to do a lot of what we do. But if we acquiesce in (or actively work towards) our work style becoming more isolated, solitary, and workstation-dependent, we do a disservice to ourselves, our patients and our future colleagues. We have spent many decades striving to bring radiology to the centre of patient care. That is not going to change any time soon, but what could change is the perception of the contribution of radiologists. If we are hidden away in an office, rarely meeting patients or referrers, it is only a small step to being forgotten. We will still produce reports, which will still be important, but we may find ourselves emerging from our bunkers in the future, troglodytes blinking as we encounter daylight, strangers to thosewith whom we once spoke, peripheral to any decisions about resources or planning, having lost our standing to others who have taken advantage of our invisibility.”
    The vanishing radiologist—an unseen danger, and a danger of being unseen
    Adrian P. Brady
    European Radiology (in press)
  • “The notion of working in peaceful isolation, spending a given number of hours daily in front of a workstation, producing meaningful and valuable output before packing up and going home, can be attractive. In some circumstances, we may be more productive (if productivity can be counted in reports generated) in this type of environment. After all, we do not need much more than regular coffee and a dark room to do a lot of what we do. But if we acquiesce in (or actively work towards) our work style becoming more isolated, solitary, and workstation-dependent, we do a disservice to ourselves, our patients and our future colleagues.We have spent many decades striving to bring radiology to the centre of patient care. That is not going to change any time soon, but what could change is the perception of the contribution of radiologists. If we are hidden away in an office, rarely meeting patients or referrers, it is only a small step to being forgotten. We will still produce reports, which will still be important, but we may find ourselves emerging from our bunkers in the future, troglodytes blinking as we encounter daylight, strangers to those with whom we once spoke, peripheral to any decisions about resources or planning, having lost our standing to others who have taken advantage of our invisibility.”
    The vanishing radiologist—an unseen danger, and a danger of being unseen
    Adrian P. Brady
    European Radiology (in press)
Small Bowel

  • “Medication-induced angioedema of the small bowel is a relatively uncommon and somewhat underdiagnosed condition associated with medications that inhibit the renin-angiotensin system. These most commonly include the angiotensin- converting enzyme (ACE) inhibitors , particularly lisinopril and enalapril, and to a lesser  extent the angiotensin II receptor blockers.”
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • "The incidence of ACE inhibitor–induced angioedema is estimated at approximately 0.3% of patients receiving this common class of medications, with contributing risk factors includ- ing African descent, a history of drug rash or seasonal allergies, and age greater than 65 years. Other reports note that adult women who are overweight are at particular risk for this disorder, which can occur days to years after these medications are initially administered.”
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • “CT findings of ACE inhibitor–induced angio- edema include circumferential wall thickening (most commonly involving the jejunum), mural stratification, straightening of bowel loops, interloop or mesenteric edema, and ascites . The laboratory findings are helpful, as there is usually a normal serum lactate level and a normal or only mildly elevated white blood cell count.”
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • "Removing the inciting agent (the ACE inhibi- tor) usually leads to complete resolution of the angioedema. Certain patients may experience repetitive episodes if the medication is not recognized as the inciting agent or if the cause is hereditary, while others may develop other sites of angioedema in the body, including in the head and neck. Keeping this relationship in mind is important for the radiologist, who may have the opportunity to be the first to suggest the diagnosis.”
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • “In the acute setting, CT findings of acute radiation enteritis may include mucosal hyperenhancement, wall thickening, and ulcer formation. Localized inflammatory changes including interloop edema, regional free fluid, and pneumatosis may also be seen. Chronic find- ings include submucosal thickening, stricturing, fistula formation, and luminal narrowing secondary to chronic intimal inflammation. The diagnosis of acute radiation enteritis primarily remains one of exclusion and depends largely on clinical history and the time course. However, recognition is helpful as these changes may be reversible, resolving with time following completion of therapy.”
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • "Acute regional or diffuse spontaneous hemorrhage in the small bowel is relatively rare but has been described in patients undergoing anticoagulation therapy or with bleeding diatheses. The most common location of acute small-bowel bleeding is in the jejunum (69%). However, hemorrhage can be diffuse or even multifocal, uncommonly causing hematoma formation across multiple segments of small bowel. On CT images, hemorrhage may manifest as circumferential thickening of the bowel wall of varying length and is often most evident on CT images obtained without intravenous contrast material. A potential secondary consequence  is bowel obstruction owing to mass effect, although most of these patients are managed conservatively.”
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • • On intravenous contrast-enhanced CT images of the abdo- men and pelvis, the “target” or “double halo” sign represents mural stratification caused by hyperenhancement of both the inner mucosa and the outer muscularis propria/serosa, with a middle layer of low-attenuating submucosal edema.  
    • Dilated loops of small bowel (>3 cm in diameter) with pa- per-thin walls should raise strong suspicion for acute vascular compromise owing to thromboembolic disease.  
    • Mechanical obstruction of two points along a short segment of small bowel in a single location can lead to a twisted C- or U-shaped configuration, the typical appearance seen in closed-loop small-bowel obstruction at CT.  
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • • Vasculitis should be considered under certain circumstances, namely in young patients, when the affected segments of small bowel are atypical in distribution (eg, in the duodenum or a patchy distribution across multiple vascular territories) and when there is associated systemic involvement by a similar process.  
    • CT findings of ACE inhibitor–induced angioedema include circumferential wall thickening (most commonly involving the jejunum), mural stratification, straightening of bowel loops, interloop or mesenteric edema, and ascites.  
    CT Findings of Acute Small-Bowel Entities  
    Sugi MD et al.
    RadioGraphics 2018; 38:1352–1369 
  • “Celiac disease is chronic intolerance of gluten that induces intestinal mucosal lesions in genetically predisposed patients. Although in most cases the symptoms and histologic abnormalities completely resolve with use of a strict gluten-free diet, com plications occur in some patients. The complications include small-bowel intussusception, ulcerative jejunoileitis, lymphoma, adenocarcinoma, hyposplenism, cavitating lymphadenopathy syndrome, and pneumatosis intestinalis.”
    Celiac Disease in Adults: Evaluation with MDCT Enteroclysis
    Philippe Soyer et al.
    AJR 2008 191:5, 1483-1492
  • “Celiac disease is now recognized as a common disease, occurring in about 1 in every 200 Americans. However, less than 10% of cases are currently diagnosed, with a diagnostic delay of more than 10 years from onset of symptoms. Celiac disease is a chronic autoimmune disorder induced in genetically susceptible individuals after ingestion of gluten proteins, which are found in wheat, rye, barley, and certain other grains. The small bowel mucosa is primarily affected, resulting in progressive degrees of villus inflammation and destruction with resulting induction of crypt hyperplasia. The destruction begins in the duodenum and over time progresses distally to the ileum. Loss of villi, which absorb fluid, and hypertrophy of crypts, which produce fluid, result in chronic fluid excess in the small bowel lumen.”
    CT Findings in Adult Celiac Disease
    Scholz FJ et al.
    RadioGraphics 2011; 31:977–992
  • “Chronic excess fluid and its effects on bowel wall structure and tone create the small bowel malabsorption pattern (MABP), which was described long ago in barium studies of patients with celiac disease. Features of the celiac disease MABP include duodenitis , dilution, dilatation, slow transit, flocculation , moulage, reversal of the jejunalileal fold pattern, and transient small bowel intussusception.”
    CT Findings in Adult Celiac Disease
    Scholz FJ et al.
    RadioGraphics 2011; 31:977–992

  • CT Findings in Adult Celiac Disease
    Scholz FJ et al.
    RadioGraphics 2011; 31:977–992
  • “Small bowel loops are often dilated and fluidfilled as a result of the chronic inflammatory process. This leads to progressive dilution of enteric contrast material. Small hyperattenuating flecks of barium may be seen precipitating in the dilated small bowel loops, a phenomenon termed flocculation. The small bowel lumen contains both intrinsic physiologic fluid and administered enteric contrast material. Peristaltic waves sweeping periodically through the bowel result in variable laminar flow of these different fluid components within the flaccid bowel lumen in a recognizable pattern.”
    CT Findings in Adult Celiac Disease
    Scholz FJ et al.
    RadioGraphics 2011; 31:977–992
  • “Prominence of upper mesenteric lymph nodes is a feature of celiac disease. Autoimmune stimulation in celiac disease provokes regional lymphocytic proliferation. The duodenum and proximal jejunum are the initial organs targeted for autoimmune destruction, and nodal prominence is most marked in the upper small bowel mesentery. Mesenteric lymph node enlargement, low-attenuation lymph nodes, and cavitating lymph nodes are well-described features of celiac disease. However, cavitating or low-attenuation lymph nodes are infrequent and are found in patients with advanced symptomatic disease.”
    CT Findings in Adult Celiac Disease
    Scholz FJ et al.
    RadioGraphics 2011; 31:977–992
Stomach

  • “Gastritis can be secondary to many etiologies including infection, systemic illness such as trauma or burns, and autoimmune disease. Peptic ulcer disease is most commonly caused by Helicobacter Pylori infection and chronic NSAID use . The most common sites for ulcer formation are the gastric antrum/pylorus and proximal duodenum. The resultant edema and fibrosis around the ulcer site can cause narrowing and eventual obstruction of the gastric outlet [9]. Prior to the widespread use of H2 blockers and proton pump inhibitors, peptic ulcer disease was the most common cause of gastric outlet obstruction, however in the era of H2 blockers, outlet obstruction now predicts malignancy. While endoscopy is the modality of choice for diagnosing gastritis, CT is often performed first particularly in the setting of acute abdominal pain.”
    Imaging of acute gastric emergencies: a case-based review  
    Jetty S et al.
    Clinical Imaging 72 (2021) 97–113
  • “On imaging, it can be difficult to distinguish benign peptic ulcer disease from malignant causes of gastric outlet obstruction and biopsy is required for confirmation. Peptic ulcers can perforate and should be recognized on imaging.”
    Imaging of acute gastric emergencies: a case-based review  
    Jetty S et al.
    Clinical Imaging 72 (2021) 97–113
  • “On CT, gastritis will appear as wall thickening with alternating hyper- and hypoattenuation representing mucosal enhancement and submucosal edema. The presence of mucosal enhancement (hyperemia) on CT suggests gastritis as the cause of gastric wall thickening. An uncommon form of gastritis is emphysematous gastritis. It is usually caused by gas-forming Escherichia coli. Initially obtained AXR may show mottled gas outlining the gastric wall. CT can confirm the diagnosis. Mottled gas can also be a sign of gastric pneumatosis from ischemia.”
    Imaging of acute gastric emergencies: a case-based review  
    Jetty S et al.
    Clinical Imaging 72 (2021) 97–113
  • "Primary gastric cancer (GC) is a common cause of cancer related death worldwide and can initially present as a gastric ulcer. The characteristic CT finding in GC is disruption of the multilayered pattern of the gastric wall enhancement with thickening, variable enhancement and ulceration. Malignancy is the most common cause of gastric outlet obstruction. Malignant obstruction is an advanced disease presentation that occurs in up to 20% of patients with primary pancreatic, gastric, or duodenal carcinomas. It can be intrinsic or extrinsic. Extrinsic obstruction is almost always due to compression of the gastric outlet from tumor growth in surrounding organs. It is most commonly seen with primary tumors of the pancreas and duodenum.”
    Imaging of acute gastric emergencies: a case-based review  
    Jetty S et al.
    Clinical Imaging 72 (2021) 97–113
  • "Fistulae can form between the stomach and adjacent viscera. In patients with chronic cholecystitis or long-standing cholelithiasis gradual erosion can develop between the inflamed gallbladder wall and stomach or first part of duodenum. The Gallstone can extend into the bowel and cause gallstone ileus, a relatively rare cause of a mechanical small bowel obstruction. CT with contrast is the imaging modality of choice. The gallstone becomes impacted in the ileocolic valve and results in pneumobillia, ectopic gallstone and proximal small bowel dilatation. A rarer form of gallstone ileus can occur where the stone is impacted in the pylorus or the duodenum and is called Bouveret syndrome. Morbidity is high and has been reported as high as 33%.”  
    Imaging of acute gastric emergencies: a case-based review  
    Jetty S et al.
    Clinical Imaging 72 (2021) 97–113
  • Cronkhite-Canada Syndrome
    - Cronkhite-Canada syndrome is characterized by numerous hamartomatous polyps in the digestive tract, with predominant involvement of the stomach, large intestine and, to a lesser extent, small bowel. The exact etiology is unknown and there is no recognized familial occurrence. Unlike other polyposis syndromes, it is not associated with malignancy.
    - Polyps are similar to those of juvenile polyposis syndrome except that the mucosa among Cronkhite-Canada syndrome polyps is edematous and inflammation of the lamina propria is usually present; by contrast, histologically the mucosa between juvenile polyposis syndrome polyps is normal 
  • Factoid
    - Desmoids in patients with FAP have a predilection for surgical sites and mostly develop after prophylactic colectomy. The small bowel mesentery and musculoaponeurotic structures of the abdominal wall near prior surgical sites are the two most common locations for desmoids in FAP. 
  • “FAP is the most common GI polyposis syndrome, characterized by the presence of more than 100 synchronous colorectal adenomas and a 100% lifetime risk of colorectal cancer. FAP is an autosomal dominant condition caused by germline mutations in the adenomatous polyposis coli (APC) gene on chromosome 5q21, although one-third of new cases are due to de novo mutations. APC is a tumor suppressor gene that functions in the Wnt pathway, and its loss leads to accumulation of b-catenin oncoprotein, with subsequent uncontrolled cellular proliferation.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • "Gastric fundic gland hamartomatous and hyperplastic polyps and duodenal adenomas are the most common extra- colonic GI findings in FAP; duodenal/periampul- lary cancer (4%–10%) is the most common cause of death in patients with FAP who have undergone prophylactic colectomy. Gastric carcinoma and small bowel polyps are not common in patients with FAP.”  
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301
  • “Desmoids in patients with FAP have a predilection for surgical sites and mostly develop after prophylactic colectomy .The small bowel mesentery and musculoaponeurotic structures of the abdominal wall near prior surgical sites are the two most common locations for desmoids in FAP. Desmoids are locally aggressive and can lead to long-term and at times devastating complications, including bowel obstruction, mesenteric ischemia, ureteric obstruction, fistula, and abscess formation . Desmoids are the cause of death in up to 10% of patients with FAP.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • “JPS is an autosomal dominant condition characterized by the presence of multiple juvenile polyps in the colon and rectum (98%), the stomach (14%), and less commonly the duodenum, jejunum, and ileum. Up to 70% of colonic polyps develop in the proximal colon.The term juvenile refers to the histologic type of the polyps, not the age of clinical diagnosis or the age of onset of polyps.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • "Large polyps are seen as masslike lesions at CT and can prolapse and cause obstruction.The antropyloric region is the most common site for gastric polyps; rarely, diffuse gastric polyposis can be seen in the absence of colonic polyps and can be identified at upper GI contrast material study. Smaller gastric polyps can be seen as multiple small nodular masses carpeting the stomach or diffuse wall thickening at CT or MRI and can mimic Ménétrier disease or diffuse linitis plastica of diffuse gastric cancer.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
  • “PJS is characterized by histologically distinc- tive hamartomatous polyps of the GI tract, most frequently in the small bowel (96%), colorectum (25%–50%), and stomach (25%), along with characteristic mucocutaneous pigmentation in the perioral area (55). PJS is an autosomal domi- nant condition due to a mutation in the STK11 tumor suppressor gene (previously called LKB1), located on chromosome 19p13, which encodes a serine-threonine kinase involved in cell cycle activities, mTOR (mammalian target of rapamy- cin) regulation, chromatin remodeling, and Wnt pathway signaling (23,55). Ninety-four percent of affected PJS families demonstrate mutations of STK11; 25% of newly diagnosed PJS cases are sporadic with de novo mutations.”
    Hereditary Gastrointestinal Cancer Syndromes: Role of Imaging in Screening, Diagnosis, and Management  
    Katabathina VS et al.
    RadioGraphics 2019; 39:1280–1301 
Trauma

  • “CTA is a frequently used first-line imaging study for the assessment of peripheral vascular trauma. CTA is usually readily available in emergency settings where trauma protocol CTs of the chest and abdomen are performed and is often faster and prone to less iatrogenic complications than conventional an- giography. Multiple specific manifestations of vascular trauma are readily demonstrated on CTA, which guide the next steps in patient management. Identification of these imaging signs is important to prevent devastating complications of vascular injury.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "CTA is now widely accepted as the first-line imaging investigation when an upper or lower extremity vascular injury is in question. Compared with conventional angiography, CTA has the advantages of being less invasive, more readily avail- able, and allowing for the evaluation of the adjacent soft tissues and bones. CTA avoids potential iatrogenic complica- tions associated with catheter angiography, such as pseudoaneurysm, hematoma, thrombosis of the access vessel, and peripheral embolization. CTA is also less expensive and can be obtained quickly, as opposed to the delay often required to assemble a specialized team to perform conventional angiography, a particular advantage of CTA when reducing ischemic time is known to be an important factor in limb salvage.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "Analyses of trauma patients who underwent upper or lower extremity CTA showed sensitivities in the range of 95–100%, specificities of 87–100%, a low nondiagnostic imaging rate, and good inter-observer agreement between radiologists indicating that CTA can replace conventional diagnostic angiography in the acute trauma setting. Several of these studies are limited by verification and follow-up bias, and although some injuries may have been missed by CTA, none of the missed injuries was likely to have been clinically significant”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "When unilateral upper extremity CTA is to be performed, an IV should be placed contralateral to the affected extremity to prevent dense venous contrast from obscuring the adjacent arteries. Optimal positioning is with the body supine with the arm over the head, palm facing upward with fingers extended. If more comfortable for the patient, prone body position- ing with the palm facing the table is also acceptable. Positioning the arm above the head helps to reduce noise; however, this may not be possible in the setting of an upper extremity injury. In such cases, the arms can be positioned at the patient’s side with images acquired in the same field-of- view as the chest, abdomen, and pelvis CT.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "Multiplanar reconstructions in the coronal and sagittal planes are performed at the scanner. Curved planar reconstructions (CPR) and maximum intensity projection (MIP) images can be constructed at the workstation. 3D renderings produced at the workstation or in a dedicated 3D lab are offered upon ordering provider request. Vascular structures are usually best viewed with window width setting around 600 and window level setting around 80.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • “A pseudoaneurysm is an injury to the artery contained by fibrous tissue or adventitia, which is in contrast to true aneurysms which contain all three layers of the vessel wall. On CTA, a pseudoaneurysm will appear as a focal contrast-filled outpouching .In contrast to active hemorrhage, pseudoaneurysms maintain their shape on delayed phase imaging, whereas contrast will increase and change shape in the setting of active hemorrhage. Occasionally, the outpouching will not entirely fill with contrast owing to the presence of thrombus. Sometimes pseudoaneurysm can have delayed presentation with atypical clinical symptoms such as compressive neuropathy or pulsatile soft tissue mass.”  
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "An  AVF occurs when traumatic injury results in a direct communication between an artery and an adjacent vein without an intervening capillary bed. The exact site of communication may not be visible; however, early filling of a vein adjacent to an artery in the region of traumatic injury (in the absence of venous filling in the more distal extremity) is indicative of an AVF.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • “Arterial vasospasm occurring in the setting of traumatic injury can be difficult to differentiate from dissection with a thrombosed false lumen. The etiology of vasospasm in the absence of visible endothelial injury is not entirely clear, but has been hypothesized to be related to mechanical stimulus from pressure waves transmitted from a high velocity pene- trating object and/or release of vasoconstrictive substances. Like other types of arterial injury, vasospasm is usually present adjacent to soft tissue injury or vessel segments along the path of the penetrating injury and appears as a narrowed segment of the artery. Management depends on the severity and length of the narrowed segment, but may include conventional angiography, MR angiography, or clinical monitoring with follow-up imaging to ensure resolution and differentiate from a true arterial injury.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "Variant vascular anatomy can be a potential source of false positives results. If an artery does not arise at its conventional location, it may be mistaken for an occlusion. In a study of conventional arteriograms of the upper extremity, variants were noted in 9% of individuals, the most common being a high origin of the radial artery from the brachial artery, with high origins of the radial and ulnar artery from the axillary artery occurring less frequently. In the lower extremity, approximately 9% of individuals have variant popliteal and tibial artery branching patterns, with high origins of the anterior tibial artery being most common. In addition, the tibial arteries may be congenitally absent or hypoplastic, and in these cases should not be confused with occlusion. Findings that suggest a congenitally absent or hypoplastic tibial artery include robust remaining tibial arteries supplying the extremity in the region of the absent artery, finding present on a prior imaging study, lack of abrupt vessel cutoff, and extended distance from region of trauma.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
Vascular

  • "Analyses of trauma patients who underwent upper or lower extremity CTA showed sensitivities in the range of 95–100%, specificities of 87–100%, a low nondiagnostic imaging rate, and good inter-observer agreement between radiologists indicating that CTA can replace conventional diagnostic angiography in the acute trauma setting. Several of these studies are limited by verification and follow-up bias, and although some injuries may have been missed by CTA, none of the missed injuries was likely to have been clinically significant”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "When unilateral upper extremity CTA is to be performed, an IV should be placed contralateral to the affected extremity to prevent dense venous contrast from obscuring the adjacent arteries. Optimal positioning is with the body supine with the arm over the head, palm facing upward with fingers extended. If more comfortable for the patient, prone body position- ing with the palm facing the table is also acceptable. Positioning the arm above the head helps to reduce noise; however, this may not be possible in the setting of an upper extremity injury. In such cases, the arms can be positioned at the patient’s side with images acquired in the same field-of- view as the chest, abdomen, and pelvis CT.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "Multiplanar reconstructions in the coronal and sagittal planes are performed at the scanner. Curved planar reconstructions (CPR) and maximum intensity projection (MIP) images can be constructed at the workstation. 3D renderings produced at the workstation or in a dedicated 3D lab are offered upon ordering provider request. Vascular structures are usually best viewed with window width setting around 600 and window level setting around 80.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • “A pseudoaneurysm is an injury to the artery contained by fibrous tissue or adventitia, which is in contrast to true aneurysms which contain all three layers of the vessel wall. On CTA, a pseudoaneurysm will appear as a focal contrast-filled outpouching .In contrast to active hemorrhage, pseudoaneurysms maintain their shape on delayed phase imaging, whereas contrast will increase and change shape in the setting of active hemorrhage. Occasionally, the outpouching will not entirely fill with contrast owing to the presence of thrombus. Sometimes pseudoaneurysm can have delayed presentation with atypical clinical symptoms such as compressive neuropathy or pulsatile soft tissue mass.”  
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "An  AVF occurs when traumatic injury results in a direct communication between an artery and an adjacent vein without an intervening capillary bed. The exact site of communication may not be visible; however, early filling of a vein adjacent to an artery in the region of traumatic injury (in the absence of venous filling in the more distal extremity) is indicative of an AVF.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • “Arterial vasospasm occurring in the setting of traumatic injury can be difficult to differentiate from dissection with a thrombosed false lumen. The etiology of vasospasm in the absence of visible endothelial injury is not entirely clear, but has been hypothesized to be related to mechanical stimulus from pressure waves transmitted from a high velocity pene- trating object and/or release of vasoconstrictive substances. Like other types of arterial injury, vasospasm is usually present adjacent to soft tissue injury or vessel segments along the path of the penetrating injury and appears as a narrowed segment of the artery. Management depends on the severity and length of the narrowed segment, but may include conventional angiography, MR angiography, or clinical monitoring with follow-up imaging to ensure resolution and differentiate from a true arterial injury.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "Variant vascular anatomy can be a potential source of false positives results. If an artery does not arise at its conventional location, it may be mistaken for an occlusion. In a study of conventional arteriograms of the upper extremity, variants were noted in 9% of individuals, the most common being a high origin of the radial artery from the brachial artery, with high origins of the radial and ulnar artery from the axillary artery occurring less frequently. In the lower extremity, approximately 9% of individuals have variant popliteal and tibial artery branching patterns, with high origins of the anterior tibial artery being most common. In addition, the tibial arteries may be congenitally absent or hypoplastic, and in these cases should not be confused with occlusion. Findings that suggest a congenitally absent or hypoplastic tibial artery include robust remaining tibial arteries supplying the extremity in the region of the absent artery, finding present on a prior imaging study, lack of abrupt vessel cutoff, and extended distance from region of trauma.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "Variant vascular anatomy can be a potential source of false positives results. If an artery does not arise at its conventional location, it may be mistaken for an occlusion. In a study of conventional arteriograms of the upper extremity, variants were noted in 9% of individuals, the most common being a high origin of the radial artery from the brachial artery, with high origins of the radial and ulnar artery from the axillary artery occurring less frequently. In the lower extremity, approximately 9% of individuals have variant popliteal and tibial artery branching patterns, with high origins of the anterior tibial artery being most common. In addition, the tibial arteries may be congenitally absent or hypoplastic, and in these cases should not be confused with occlusion..”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • “CTA is a frequently used first-line imaging study for the assessment of peripheral vascular trauma. CTA is usually readily available in emergency settings where trauma protocol CTs of the chest and abdomen are performed and is often faster and prone to less iatrogenic complications than conventional an- giography. Multiple specific manifestations of vascular trauma are readily demonstrated on CTA, which guide the next steps in patient management. Identification of these imaging signs is important to prevent devastating complications of vascular injury.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
  • "CTA is now widely accepted as the first-line imaging investigation when an upper or lower extremity vascular injury is in question. Compared with conventional angiography, CTA has the advantages of being less invasive, more readily avail- able, and allowing for the evaluation of the adjacent soft tissues and bones. CTA avoids potential iatrogenic complica- tions associated with catheter angiography, such as pseudoaneurysm, hematoma, thrombosis of the access vessel, and peripheral embolization. CTA is also less expensive and can be obtained quickly, as opposed to the delay often required to assemble a specialized team to perform conventional angiography, a particular advantage of CTA when reducing ischemic time is known to be an important factor in limb salvage.”
    Imaging primer for CT angiography in peripheral vascular trauma  
    Lara Walkoff et al.
    Emergency Radiology (2021) 28:143–152
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