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

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

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Cardiac

  • “The left ventricle pseudoaneurysm is an anomaly of the left ventricle and is severed and joined with a pocket look. There may be secondary to a myocardial infarction, trauma, or surgical procedure. Sometimes the cause is not found. Complications are heart failure, arrhythmias, vascular embolism, and sudden death. The treatment is surgical only.”
    Left ventricle pseudoaneurysm: contribution of multimodality imaging to the diagnosis.
    Bertrand Fikahem EM et al.  
    Case Rep Cardiol. 2014;2014:531929
  • “The diagnosis of LVPA is placed in the imaging. The deformation of the cardiac shadow is noted in standard radiography. However, the heart may have a normal appearance. Echocardiography leads to diagnosis, objectifying communication between the left ventricle and the pocket, as in the case we described. The delimitation of contours can be complicated by the configuration of the pocket. Indeed, ultrasound appeared limited in our case, because the pseudoaneurysm communicated with the left ventricle at the tip, and went back under the ribs forward. Transesophageal ultrasound would have a better analysis of the pseudoaneurysm. CT scan has proven to be an indispensable tool in our case, to define the limits of pseudoaneurysm.”
    Left ventricle pseudoaneurysm: contribution of multimodality imaging to the diagnosis.
    Bertrand Fikahem EM et al.  
    Case Rep Cardiol. 2014;2014:531929
  • “Clinical distinction between true and pseudoaneurysms remains a challenge, but it is important to guide proper management. LV aneurysm describes a saccular protrusion containing the full thickness of the thinned LV wall with scarred myocardium that balloons outward, and akinesia or dyskinesia. Transmural MI is the major underlying cause of LV aneurysm, and usually involves the apical, anterior, or anterolateral wall. Cardiac CT and MR imaging findings include a wide mouth, smooth transition from normal myocardium to thinned, scarred myocardium with delayed enhancement, and akinesia or dyskinesia during systole. Fatty replacement or calcification of the infarcted myocardial wall and thrombus formation may be present.”
    Left ventricle pseudoaneurysm: contribution of multimodality imaging to the diagnosis.
    Bertrand Fikahem EM et al.  
    Case Rep Cardiol. 2014;2014:531929
  • “LV pseudoaneurysm results from rupture of the LV free wall, contained by an overlying adherent pericardium or scar tissue. Pseudoaneurysm is more commonly seen in inferior and lateral wall segments attributed to MI following left circumflex coronary artery occlusion. Unlike the wide mouth of a true aneurysm, the mouth of a pseudoaneurysm is narrower than the diameter of the aneurysm. Other imaging findings include abrupt transition from normal myocardium to aneurysm, a distinct discontinuity of the ventricular wall, and dyskinesia during both systole and diastole. Pseudoaneurysms have poor prognoses because of the high risk of expansion and rupture, leading to cardiac tamponade, shock, and death. Therefore, they call for urgent surgical repair.”
    Left ventricle pseudoaneurysm: contribution of multimodality imaging to the diagnosis.
    Bertrand Fikahem EM et al.  
    Case Rep Cardiol. 2014;2014:531929
  • Cardiac Tumors: Factoids
    - Primary tumors are rare and metastases to the heart are more common (20-40x more common)
    - 75% of primary cardiac tumors are benign (most commonly myxoma)
    - 25% of primary cardiac tumors are malignant (most commonly sarcomas)

  • Cardiac Masses on Cardiac CT: A Review 
    David Kassop  et al.
    Curr Cardiovasc Imaging Rep (2014) 7:9281 
  • Cardiac CT: Key Findings
    - size, 
    - quantity, 
    - location (cardiac chamber, pericardial involvement, extracardiac structures),
    - morphology (attach-ment, margin appearance, infiltration), 
    - tissue characteristics (calcification, fat attenuation, vascularity)
    - clinical correlation (known malignancy or infection, presence of a catheter, associated syndromes) 
  • Cardiac Myxoma: Facts
    - Myxoma is the most common primary cardiac tumor, account- ing for 25-50 % of cases.
    - typically affects middle-aged adults, 30-60 years of age, with a higher prevalence in women.
    - majority (60-75 %) of cases are located in the left atrium attached to the fossa ovalis by a thin stalk, though less common locations include the right atrium (15-20 %), inferior vena cava, ventricles, and the valve leaflets
  • Myxoma is the most common primary cardiac tumor, accounting for 25-50 % of cases. It typically affects middle-aged adults, 30-60 years of age, with a higher prevalence in women. A majority (60-75 %) of cases are located in the left atrium attached to the fossa ovalis by a thin stalk, though less common locations include the right atrium (15-20 %), inferior vena cava, ventricles, and the valve leaflets.  
    Cardiac Masses on Cardiac CT: A Review  
    David Kassop  et al.
    Curr Cardiovasc Imaging Rep (2014) 7:9281
  • “On cardiac CT, approximately two-thirds of myxomas are ovoid with a smooth or lobular shape, with the remainder villous in appearance. When visualized on non-contrast CT, they typically appear hypodense, consistent with blood, and may demonstrate calcifications more often in the right atrial location. On contrast-enhanced cardiac CT, myxomas appear as intracavitary filling defects with heterogeneous con- trast enhancement, though the intensity may be variable de- pending on their chronicity and whether necrosis or hemorrhage is present.”
    Cardiac Masses on Cardiac CT: A Review  
    David Kassop  et al.
    Curr Cardiovasc Imaging Rep (2014) 7:9281
  • Cardiac Lipoma
    - Lipoma is the second most common primary benign tumor and accounts for approximately 10 % of primary cardiac tumors 
    - Lipomas commonly occur in middle-aged and older adults. 
    - Lipomas are encapsulated, well-circumscribed tumors consisting of mature adipocytes that can occur any- where in the heart. Approximately 50 % arise in the epicardial or mid-myocardial layers, while the other half are subendocardial, where they create filling defects with a homogenous appearance of fat attenuation (density < -50 Hounsfield units [HU]). 
  • Papillary Fibroelastoma 
    - Papillary fibroelastoma is the third most common primary benign cardiac tumor with an incidence of up to 0.33 % in autopsy series 
    - Papillary fibroelastomas account for ap- proximately 75 % of all cardiac valvular tumors and affect men and women equally with a mean age of 60 years 
    - They are characterized by a collection of avascular fronds of dense connective tissue lined by endothelium and may arise from any endocardial surface, though the majority are found on the aortic and mitral valves. Most papillary fibroelastomas are solitary and small with an average diameter of 10 mm. 

  • Cardiac Masses on Cardiac CT: A Review 
    David Kassop  et al.
    Curr Cardiovasc Imaging Rep (2014) 7:9281 
  • Metastatic Tumors to the Heart
    - Malignant cardiac tumors are most often a result of metastatic disease arising by direct extension of adjacent organs or spread via hematogenous, lymphatic, or intracavitary routes 
    - The most common malignancies metastatic to the heart originate from the lung (35-40 %), followed by breast (10 %) and hematologic (10-20 %) carcinomas. Melanoma has the greatest propensity to metastasize to the heart, but it is often found late in the disease process
  • Metastatic Tumors to the Heart
    - The most frequent location of metastasis is the pericardium (65-70 %), followed by epicardium (25-35 %) and myocardium (30 %). Endocardial or intracavitary involvement is rarely observed (3.5 % of cases) [18•]. 
  • Cardiac Angiosarcoma
    - Angiosarcoma is the most common primary cardiac malignant tumor and is comprised of cells that develop multiple, irregular vascular channels. The primary site of origin is the right atrial free wall in 80 % of cases and less commonly the right ventricle or pericardium The tumor morphology typically consists of a large, multilobar mass with a heterogeneous composition that spreads along the epicardial surface and replaces the right atrial wall 
    - These tumors may also be localized to the pericardium and often invade adjacent cardiac structures leading to cardiomegaly and recurrent pericardial effusions 
  • Rhabdomyosarcoma: facts
    - Rhabdomyosarcoma is the second most common primary malignant tumor. It accounts for 4-7 % of cardiac sarcomas and remains the most common pediatric cardiac malignancy. 
    - It is a malignant tumor of striated muscle that always involves the myocardium. In contrast to angiosarcomas, rhabdomyosarcomas may arise from any location with no predilection for a specific cavity as 60 % of cases involve multiple sites of origin. Additionally, the tumors may invade the pericardial space with a characteristic nodular appearance .
  • Intracardiac Thrombus: facts
    Thrombus accounts for the most commonly encountered intra- cardiac mass. It can occur in any of the cardiac chambers, though it most often involves the left-sided structures. Thrombus formation can be caused by hypercoagulable states, systolic dysfunction with wall motion abnormalities, atrial fibrillation, or artificial devices. It typically appears as a hypodense, low-attenuation filling defect in a contrast pool within a cardiac chamber and may be differentiated from primary and secondary tumors by knowledge of predisposing risk factors, attachment location, shape, and lack of mobility. 
  • Left Atrial Appendage Thrombi
    Cardiac CT has very high sensitivity for excluding thrombus of the left atrial appendage but findings of low attenuation in the left atrial appendage (LAA) are not specific to thrombus as this often represents circulatory stasis, an incomplete mixing of contrast material and blood. This “pseudo” filling defect may mimic thrombus, especially in low-flow states. However, delayed imaging of the LAA may significant- ly improve the specificity to distinguish thrombus from circulatory stasis.
  • Left Ventricle Thrombus: facts
    Left ventricular thrombi are often located in an area of myocardial hypokinesis, dyskinesia or aneurysm formation. They are frequently crescent-shaped filling defects with broad based attachments. However, a pedunculated appearance has been observed and can mimic myxom. Chronic thrombi may develop spotty calcifications, though this feature has not been shown to significantly differentiate thrombus from myxoma. Thrombus within the left ventricle may be distinguished from myocardi- um by lower attenuation characteristics with a threshold of 65 HU providing a sensitivity and specificity of 94 % and 97 %, respectively. 
  • Valvular Vegatations
    Cardiac CT has demonstrated to be highly accurate in identifying valvular vegetations, with a sensitivity of 97 % and specificity of 88 % as compared to transesophageal echocardiography. On cardiac CT, vegetations appear as low- attenuation masses usually involving the valve leaflet free edge. As a result, vegetations can lead to valvular destruction and/or dysfunction and cardiac CT is partic- ularly helpful in identifying perivalvular complications, such as perivalvular abscess formation, valve perforation, aortic pseudoaneurysms or extracardiac manifestations, such as sep- tic emboli to the lung parenchyma. 
  • Pericardial Cyst: Facts
    Pericardial cysts are benign, congenital lesions that ac- count for 7 % of all mediastinal tumors [35]. Over 75 % are located within the cardiophrenic spaces, the majority of which have a right-sided predominance. This anatomic location helps to distinguish pericardial cysts from other similar findings to include bronchogenic cysts, thymic cysts, and cardiac teratomas. Additionally, with pericardial cysts, there is no connection with the pericardial space, unlike that of pericardial diverticulae. On cardiac CT, pericardial cysts are thin-walled structures that are sharply demarcated, lack septae, and have a homogenous appearance. They are non-enhancing lesions with intravenous contrast administration and have attenuation similar to water (-10 to 20 HU). 
    Cardiac Masses on Cardiac CT: A Review 
    David Kassop  et al.
    Curr Cardiovasc Imaging Rep (2014) 7:9281 
  • Cardiac Tumor: Clinical Presentation
    1.Systemic: constitutional (fever, arthralgias, weight loss, fatigue) and paraneoplastic syndromes (PCTs).
    2.Cardiac: mass effect interfering with myocardial function or blood flow, resultant arrhythmias, interference with heart valves causing regurgitation, or pericardial effusion with or without tamponade. Typical symptoms include dyspnea, chest discomfort, pre-syncope, or syncope.
    3. Embolic: pulmonary and/or systemic thromboembolic phenomenon from the tumor.
    Cardiac Tumors: JACC CardioOncology State-of-the-Art Review.” 
    Tyebally, Sara et al. 
    JACC. CardioOncology vol. 2,2 293-311. 16 Jun. 2020, 
  • Cardiac Myxomas: Facts
    - Cardiac myxomas are the most common PCT and are believed to be derived from mesenchymal cell precursors. 
    - They form intracavitary masses, which are most commonly found in the left atrium attached by a stalk to the fossa ovalis, but may be seen in the right atrium in children. Other anatomical origins include the atrial free wall and mitral valve leaflets; however, these are less likely. 
    - Association with Carney complex (a multiple neoplasia and lentiginosis syndrome) is well established in 7% of patients found to have a cardiac myxoma on presentation.
    - Mean age at diagnosis is 50 years, and approximately 70% occur in women.
  • Cardiac myxomas: Facts
    - On cardiac CT, myxomas often manifest as a low-attenuation intracavitary mass with a smooth or slightly villous surface. 
    - Calcification is seen in approximately 14% of patients and is more commonly associated in right-sided lesions. 
    - Arterial-phase contrast enhancement is usually not present , but heterogeneous enhancement is recognized on studies performed with a longer time delay. 
  • Cardiac Lipoma
    - Lipoma is the second most common primary benign cardiac neoplasm (8% to 12%) and most commonly occurs in middle-aged and older adults. 
    - Approximately 50% of lipomas originate from the subendocardial layer, and the other half arise from the subepicardial or myocardial layers and grow into the pericardial sac. 
    - They are typically asymptomatic but may cause arrhythmias or valvular dysfunction . Subepicardial lipomas can compress the coronary arteries, which leads to ischemic chest pain.
  • Cardiac Angiosarcoma: Facts
    - highly aggressive tumors consisting of irregularly shaped vascular channels lined by anaplastic epithelial cells with sizeable areas of necrosis and hemorrhage.
    - They preferentially affect men and have a peak incidence in the fourth decade of life. 
    - They are of right atrial origin in approximately 75% of cases and typically fill this chamber and then infiltrate into the pericardium, tricuspid valve, right ventricle, and right coronary artery . 
    - Metastases develop in 47% to 89% of patients, most commonly to the lungs but also to the bone, colon, and brain. Patients typically present with symptoms of right heart failure, shortness of breath due to hemopericardium, and palpitations secondary to supraventricular arrhythmias.
  • Primary Cardiac Lymphoma: Facts
    - Primary cardiac lymphomas are mainly aggressive B-cell lymphomas seen more commonly in immunocompromised individuals. These tumors have a predilection for the right side of the heart and can present with nonspecific symptoms, including constitutional symptoms.
    - Nearly all primary cardiac lymphomas are aggressive B-cell lymphomas, with an increasing incidence secondary to lymphoproliferative disorders related to Epstein-Barr virus in patients with AIDS and in patients who have received transplants. The mean age at diagnosis is 63 years of age. 
    - They most commonly involve the right side of the heart, particularly the right atrium, but any chamber can be involved. There are frequently multiple lesions.
  • Cardiac Metastases
    Cardiac metastases are 20 to 40 times more common than PCTs. Up to 12% of oncology patients have metastases to the heart or pericardium at autopsy, although most remain clinically silent. Melanomas have the greatest propensity for cardiac involvement, whereas carcinomas of the thorax, including breast, lung, and esophageal, are the most common carcinomas that metastasize to the heart. Malignant tumors use 1 of 4 routes to reach the heart , including hematogeneous, lymphatic, transvenous spread, or direct invasion. In addition, the metastatic route significantly determines the target tissue. For instance, masses that spread through the lymphatics often seed the pericardium or epicardium.

  • Pathology, imaging, and treatment of cardiac tumours.
    Maleszewski, J., Anavekar, N., Moynihan, T. et al.  
    Nat Rev Cardiol 14, 536–549 (2017).

  • Pathology, imaging, and treatment of cardiac tumours.
    Maleszewski, J., Anavekar, N., Moynihan, T. et al.  
    Nat Rev Cardiol 14, 536–549 (2017).
  • “Primary cardiac tumours are very rare with a prevalence rate ranging from 0.001 to 0.03% in autopsy series. Most primary cardiac tumours are benign, such as myxoma, lipoma, papillary fibroelastoma and rhabdomyoma. Angiosarcomas and myxofibrosarcomas are the most common sarcomas of the heart. However, a primary cardiac chondroblastic osteosarcoma in the heart is a unique case, due to the fact that this type is considered to be a member of the extraskeletal osteosarcoma (ESOS) family.”
    Extraskeletal chondroblastic osteosarcoma in the left atrium  
    Özge Korkmaza et al.
    Interactive CardioVascular and Thoracic Surgery 19 (2014) 1077–1079
  • “ESOS is an uncommon malignant neoplasm, which can produce osteoid, bone or chondroid matrix, located in the soft tissue without connection to the skeleton. The most common location is the lower extremity, especially the thigh, followed by the upper extremity and the retroperitoneum.”
    Extraskeletal chondroblastic osteosarcoma in the left atrium  
    Özge Korkmaza et al.
    Interactive CardioVascular and Thoracic Surgery 19 (2014) 1077–1079
  • “The current study reported a primary cardiac chondroblastic osteosarcoma, which is a subtype of ESOS and in which the heart is an uncommon localization. Unfortunately, this tumour has aggressive behaviour and poor prognosis.”
    Extraskeletal chondroblastic osteosarcoma in the left atrium  
    Özge Korkmaza et al.
    Interactive CardioVascular and Thoracic Surgery 19 (2014) 1077–1079
  • “Extraskeletal osteosarcomas are rare malignancies that account for about 1% of all soft tissue sarcomas. Only a few large series of these tumours have been reported. These tumours are usually located in the lower and upper extremities, the thigh, or the buttocks (45–62%).4 Because of its rarity and the absence of a specific biomarker, extraskeletal osteosarcoma is easily mistaken for myositis ossificans or a benign tumour.The heart and pericardium are unusual sites for primary tumours, the prevalence rate in autopsy studies being only 0.001–0.3%; metastatic tumours are far more common.”
    Primary extraskeletal chondroblastic osteosarcoma of the pericardium: a case report and literature review,  
    Qianqian Wang et al.  
    European Heart Journal - Case Reports, Volume 4, Issue 4, August 2020, Pages 1–7
  • “Primary cardiac neoplasms occur at an incidence of 30 per 100,000 people per year. Approximately 80% of primary cardiac tumors are benign. The World Health Organization has classified neoplasms of the heart into either benign tumors and tumorlike lesions such as myxoma, malignant lesions such as angiosarcoma, and pericardial tumors such as solitary fibrous tumors. In patients older than 16 years, the most common primary cardiac neoplasms are myxomas, lipomatous tumors, and papillary fibroelastomas. In patients younger than 16 years, the most common tumors are rhabdomyomas, teratomas, fibromas, and myxomas.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "The most common presenting symptom of a cardiac tumor is dyspnea, but the manifestations of a neoplasm will depend on the location of the lesion and size. Even benign cardiac tumors may cause obstruction of blood flow, decreased cardiac output, arrhythmia, or heart failure, which can be fatal. In addition, systemic manifestations such as fatigue, anorexia, and fever may also be seen.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Cardiac myxoma is the most common benign primary cardiac neoplasm, accounting for up to 80% of all cases,5 but only represent 10% of benign primary cardiac tumors in children. Approximately 3% to 10% of cardiac myxomas are associated with Carney complex,6 an autosomal dominant disorder characterized by pigmented lesions of the skin and mucosae, cardiac myxomas, cutaneous tumors, and multiple other endocrine and nonendocrine neoplasms.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Although they can be located in any chamber, most myxomas are located within the left atrium and originate at the interatrial septum. These lesions may have an irregular border, a pedunculated morphology, and be mobile. The size of the tumor is related to the degree of mobility and the potential that the lesion can obstruct the atrio- ventricular valve.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Although computed tomography (CT) is not the preferred method to characterize the tumor, typical findings on a contrast-enhanced CT include a spherical or ovoid mass that is lower in attenuation than surrounding myocardium.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • “Rhabdomyoma is the most common primary cardiac tumor of infancy and childhood representing 60% of pediatric primary cardiac neoplasms.These lesions are most often diagnosed during the first year of life or prenatally. Cardiac rhabdomyomas are associated with tuberous sclerosis in 30% to 50% of cases but also occur sporadically and rarely in association with congenital heart disease. Tuberous sclerosis is char- acterized by cortical tubers and subependymal nodules within the brain, multiple retinal hamarto- mas, adenoma sebaceum of the skin, and periungual fibromas.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • “Rhabdomyomas are most commonly located within the ventricles attached to the myocardium but are less commonly located in the atrioventricular groove. They are multiple in 60% of cases, typically in the setting of tuberous sclerosis. On contrast-enhanced CT, they are most often hypodense masses with little contrast enhancement.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Cardiac angiosarcomas are the most common pri- mary cardiac malignancy in adults with specific differentiation, accounting for 40% of cardiac sar- comas. Patients are usually younger than 65 years, peaking in the fourth to fifth decade, with a slight male preponderance of 1.3:1.  Cardiac angiosarcomas occur almost exclusively in the right atrium near the atrioventricular sulcus (80%–90% of cases). Symptoms generally result from obstruction, tumor emboli, or local invasion into the myocardium and atrial free wall.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "These tumors are prone to local and distant metastases with the lung being the most common site. Additional areas reported include the liver, mediastinal lymph nodes, bone, adrenal glands, and spleen. Patients undergoing surgical resection interestingly demonstrate a propensity for brain metastases, thought to be due to intravascular dissemination at tumor resection and manipulation.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Cardiac angiosarcomas occur in the right atrium 80% to 90% of the time. At surgical resection, the mass typically projects into the cardiac chambers with permeative growth into the myocardium and local invasion of the pericardium, vena cava, tricuspid valve, and even the coronary arteries. Gross pathology reveals a large lobulated mass that is dark red and brown in color, reflecting its hemorrhagic and necrotic components. If pericardial invasion is present, a thickened rind of gray- black tissue is observed that is inseparable from the remainder of the tumor.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Most of the primary malignant cardiac tumors are sarcomas, accounting for greater than 90% of  cases. Undifferentiated high-grade pleomorphic sarcoma (UHGPS), rhabdomyosarcoma (RS), os- teosarcoma (OS), and leiomyosarcoma (LS) are discussed further. The most common of these tumors is UHGPS, previously known as malignant fibrous histiocytoma. UHGPS has a slight female predominance with a mean age of 47 years with a wide age range. RS, on the other hand, is the most common primary cardiac malignancy of childhood.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "Primary cardiac lymphoma (PCL) is a rare extranodal lymphoma accounting for 1% to 1.5% of all primary cardiac tumors, with the majority involving the right heart. PCLs are aggressive and are usually of the non-Hodgkin type. A typical patient is an immunocompetent male adult (2:1 male to fe- male ratio) in his 6th to 7th decade of life. The mean age is 60 years with a range of 12 to 86 years.44 Certain subtypes occur more commonly in the immunocompromised. Post- transplant lymphoproliferative disorder, a B-cell proliferation related to Epstein-Barr virus infection, may develop mostly in lung and cardiac transplant recipients. Primary effusion lymphoma (PEL) uniquely affects patients with human immunodeficiency virus, which is associated with human herpesvirus-8 (HHV-8)/Kaposi sarcoma– associated herpesvirus.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • “PCL commonly presents as a homogenously low- attenuating, hypoenhancing mass on contrast- enhanced CT, involving the right atrium or right ventricle in 92% of cases. Necrosis and involvement of the cardiac valves are atypical and, if pre- sent, should invoke an alternative diagnosis such as angiosarcoma. Extension along the epicardial surface with encasement of the coronary arteries, aortic root, and great vessels is classic. There is often pericardial thickening and massive pericardial effusion, which can occasionally be the only imaging manifestation, particularly in the PEL subtype.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
  • "When confronted with a cardiac mass, the most important imaging considerations are the location of the tumor, the possibility of metastatic disease, and the clinical presentation. When considering the differential diagnosis for primary malignant cardiac masses, location is usually the most helpful feature. Myxomas tend to be left sided, and their overall frequency skews left-sided heart masses as more frequently benign. Cardiac lymphoma and angiosarcoma, the most common primary cardiac malignancies are predominantly right sided. Necrosis, surface enhancement (“sun-ray” appearance), and valvular involvement favor angiosarcoma, whereas homogeneity and vascular encasement favor lymphoma. Other cardiac sarcomas tend to be left sided, specifically arising from the posterior wall of the left atrium.”
    Cardiac Neoplasms Radiologic-Pathologic Correlation  
    John P. Lichtenberger III et al.
    Radiol Clin N Am 59 (2021) 231–242 
Chest

  • Lemierre syndrome is a rare and potentially life-threatening complication of bacterial infections that usually affects previously-healthy adolescents and young adults. It most commonly develops in association with a bacterial throat infection, but it may develop in association with an infection involving the ears, salivary glands (parotitis), sinuses, or teeth; or in association with an Epstein-Barr infection.[1] The bacteria typically responsible for infection in Lemierre syndrome is Fusobacterium necrophorum, although a variety of bacteria can be responsible. In people with Lemierre syndrome, the initial infection spreads into tissues and deep spaces within the neck, leading to the formation of an infected blot clot (septic thrombophlebitis), sometimes made up of pus, in the internal jugular vein (the blood vessel that carries blood away from the brain, face, and neck).
    https://rarediseases.info.nih.gov/diseases/6882/lemierre-syndrome
  • “Advanced Lemierre syndrome is a life-threatening condition.The current mortality (death due to the syndrome) is estimated to be between 5% and 18%, depending on the source of the data. However, as the mortality in the pre-antibiotic era reportedly was 90%, the outlook for people with Lemierre syndrome has improved significantly due to advances in antibiotic therapy and high-level intensive care.Receiving the diagnosis as quickly as possible and starting appropriate treatment increases the chance of survival. Severe complications of Lemierre syndrome may include osteomyelitis (bone infection), meningitis, acute respiratory distress syndrome, and septic shock.”
    https://rarediseases.info.nih.gov/diseases/6882/lemierre-syndrome
  • “The identification of thrombophlebitis of the IJ vein is the first hard evidence to suggest Lemierre’s syndrome in many patients. It is likely true that, as with our patient, these imaging studies are ordered in the majority of patients to assess for deep space infections of the neck and not IJ vein thrombophlebitis. Duplex ultrasonography, CT and magnetic resonance imaging have all been used for IJ vein imaging, with CT being most commonly requested in patients with Lemierre’s syndrome. Many authors consider contrast-enhanced CT as the preferred study in this setting as it allows for visualization of surrounding structures and is the most readily available.”
    Lemierre's syndrome.  
    Eilbert W, Singla N.  
    Int J Emerg Med. 2013;6(1):40. 
  • “Lemierre’s syndrome occurs primarily in young, otherwise healthy individuals and is characterized by a history of recent oropharyngeal infection, clinical or radiological evidence of IJ venous thrombosis and anaerobic bacteremia caused primarily by F. necrophorum. This is a rare illness in the modern era of antibiotic therapy, though it has been reported with increasing frequency in the twenty-first century. Lemierre’s syndrome should be suspected in young, healthy patients with prolonged symptoms of pharyngitis followed by symptoms of septicemia or pneumonia, or an atypical lateral neck pain. Diagnosis is often confirmed by the identification of IJ vein thrombophlebitis by an imaging study and growth of anaerobic bacteria on blood culture. Prolonged antibiotic therapy is the cornerstone of treatment, occasionally combined with anticoagulation.”
    Lemierre's syndrome.  
    Eilbert W, Singla N.  
    Int J Emerg Med. 2013;6(1):40. 
Deep Learning

  • “InterpretML is an open-source Python package which exposes machine learning interpretability algorithms to practitioners and researchers. InterpretML exposes two types of interpretability – glassbox, which are machine learning models designed for interpretability (ex: linear models, rule lists, generalized additive models), and blackbox explainability techniques for explaining existing systems (ex: Partial Dependence, LIME). The package enables practitioners to easily compare interpretability algorithms by exposing multiple methods under a unified API, and by having a built-in, extensible visualization platform. InterpretML also includes the first implementation of the Explainable Boosting Machine, a powerful, interpretable, glassbox model that can be as accurate as many blackbox models.”
    InterpretML: A Unified Framework for Machine Learning Interpretability  
    Harsha Nori et al.
    arXiv Sept 2019
  • Explainable Boosting Machine (EBM) 
    EBMs are highly intelligible, because the contribution of each feature to a final prediction can be visualized and understood by plotting fj. Because EBM is an additive model, each feature contributes to predictions in a modular way that makes it easy to reason about the contribution of each feature to the prediction. 
  • In terms of predictive power, EBM often performs surprisingly well, and is comparable with state of the art methods like Random Forest and XGBoost.1 To keep the individual terms additive, EBM pays an additional training cost, making it somewhat slower than sim- ilar methods. However, because making predictions involves simple additions and lookups inside of the feature functions fj, EBMs are one of the fastest models to execute at prediction time. EBM’s light memory usage and fast predict times makes it particularly attractive for model deployment in production. 
  • “In this paper, we consider a partially supervised setting, where cheap image-level annotations are provided for all the train- ing data, and the costly per-voxel annotations are only available for a subset of them. We propose an Inductive Attention Guidance Network (IAG-Net) to jointly learn a global image-level classifier for normal/PDAC classification and a local voxel-level classifier for semi-supervised PDAC segmentation. We instantiate both the global and the local classifiers by multiple instance learning (MIL), where the attention guidance, indicating roughly where the PDAC regions are, is the key to bridging them: For global MIL based normal/PDAC classification, attention serves as a weight for each instance (voxel) during MIL pooling, which eliminates the distraction from the background; For local MIL based semi-supervised PDAC segmentation, the attention guidance is inductive, which not only provides bag-level pseudo-labels to training data without per-voxel annotations for MIL training, but also acts as a proxy of an instance-level classifier.”
    Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 

  • Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 

  • Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 
  • “This paper addresses the problem of PDAC prediction i.e., normal/PDAC classification and PDAC segmentation under the partially supervised setting. We present an Inductive Attention Guidance (IAG) strategy for learning a global image-level clas- sifier for normal/PDAC segmentation and a local instance-level classifier for semi-supervised PDAC segmentation, which enjoys the advantages of bridging the MIL-based global and local classifiers. We showed empirically on the JHMI dataset the superiority of the proposed IAG-Net for PDAC predic- tion, which is helpful to computer-assisted clinical diagnoses. Additionally, we verified the generality of IAG-Net on the pancreas tumor segmentation dataset in MSD challenge.”  
    Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021
  • “This study aimed to investigate the diagnostic ability of carcinoembryonic antigen (CEA), cytology, and artificial intelligence (AI) by deep learning using cyst fluid in differentiating malignant from benign cystic lesions. We retrospectively reviewed 85 patients who underwent pancreatic cyst fluid analysis of surgical specimens or endoscopic ultrasound-guided fine-needle aspiration specimens. AI using deep learning was used to construct a diagnostic algorithm. CEA, carbohydrate antigen 19-9, carbohydrate antigen 125, amylase in the cyst fluid, sex, cyst location, connection of the pancreatic duct and cyst, type of cyst, and cytology were keyed into the AI algorithm, and the malignant predictive value of the output was calculated. Area under receiver-operating characteristics curves for the diagnostic ability of malignant cystic lesions were 0.719 (CEA), 0.739 (cytology), and 0.966 (AI). In the diagnostic ability of malignant cystic lesions, sensitivity, specificity, and accuracy of AI were 95.7%, 91.9%, and 92.9%, respectively. AI sensitivity was higher than that of CEA (60.9%, p = 0.021) and cytology (47.8%, p = 0.001). AI accuracy was also higher than CEA (71.8%, p < 0.001) and cytology (85.9%, p = 0.210). AI may improve the diagnostic ability in differentiating malignant from benign pancreatic cystic lesions.”
    Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions  
    Yusuke Kurita et al.
    Scientific Reports | (2019) 9:6893 
  • "Although cytology had excellent specificity, it has a limited role because of its lack of sensitivity in previous studies30–32. In the present study, the sensitivity of cytology in differentiating malignant from benign cystic lesions was 47.8%. Thus, we constructed AI using deep learning algorithm for differentiating malignant from benign pancreatic cystic lesions based on the analysis of pancreatic cyst fluid and clinical data.”  
    Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions  
    Yusuke Kurita et al.
    Scientific Reports | (2019) 9:6893 
  • "In this study, AI using deep learning analyzed pancreatic cyst fluid and clinical data. By using this deep learning method, AI learns the characteristics of malignant cystic lesions by combining cyst fluid analysis and clinical data, and AI can possibly exclude the bias generated by human judgment. Although it is difficult for clinicians to diagnose malignant pancreatic cystic lesions by cyst fluid analysis and clinical data, AI using deep learning achieved adequate diagnostic ability in differentiating malignant from benign cystic lesions compared to cyst fluid analysis such as CEA and cytology. AI and CEA were also significant factor in the multivariate analysis of malignant cystic lesion. Specifically, although it is generally a problem that cytology diagnosis has low sensitivity, AI using deep learning achieved high sensitivity (95.7%).”
    Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions  
    Yusuke Kurita et al.
    Scientific Reports | (2019) 9:6893 
  • “Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • “We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • “Two dilemmas make pancreatic cyst clinical management challenging. First, it is difficult to differentiate IPMNs and MCNs, collectively termed “mucin-producing cysts,” from cysts that have no malignant potential and do not require any follow-up. Second, it can be difficult to differentiate patients with mucin-producing cysts that harbor early invasive cancer or high-grade dysplasia from patients with less advanced mucin-producing cysts. Surgery is recommended for patients with advanced cysts, whereas intermittent surveillance with imaging, rather than surgery, is considered appropriate for patients with less advanced cysts. Currently available clinical tools, however, are imperfect at assigning the most appropriate management strategies for patients with cysts. This is highlighted by the fact that 25% of cyst patients who undergo surgical resection have a pancreatic cyst with no malignant potential, and up to 78% of mucin-producing cysts referred for surgical resection are ultimately found not to be advanced, that is, they do not harbor high-grade dysplasia or cancer.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772

  • A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772

  • A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772

  • A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  •  “In conclusion, the use of a comprehensive test that evaluates clinical, imaging, and molecular features is imperfect but appears to offer substantial improvements over standard-of-care management of patients with pancreatic cysts. CompCyst does not replace conventional clinical tools. Instead, it contributes additional information, allowing clinicians to make more informed decisions. How and when tests like CompCyst can be implemented in routine clinical settings remains to be determined, but our results represent the next stage of research required for such implementation. An important next test of the markers presented here could be their validation in a follow-up, prospective study.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • OBJECTIVE. Pancreatic ductal adenocarcinoma (PDAC) is often a lethal malignancy with limited preoperative predictors of long-term survival. The purpose of this study was to evaluate the prognostic utility of preoperative CT radiomics features in predict- ing postoperative survival of patients with PDAC.  
    RESULTS. The mean age of patients with PDAC was 67 ± 11 (SD) years. The mean tumor size was 3.31 ± 2.55 cm. The 10 most relevant radiomics features showed 82.2% ac- curacy in the classification of high-risk versus low-risk groups. The C-index of survival prediction with clinical parameters alone was 0.6785. The addition of CT radiomics features improved the C-index to 0.7414.  
    CONCLUSION. Addition of CT radiomics features to standard clinical factors improves survival prediction in patients with PDAC.  
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “Tumors are spatially heterogeneous structures that can be characterized at a macro scale, and normal parenchyma can also be affected by the growth of the tumor. Texture analysis using medical images, especially radiomics approaches, is an established technique that describes spatial variations in pixel intensities in images for quantitative assess- ment. Whereas radiologists may qualitatively describe PDAC enhancement patterns as, for example, homogeneously isoattenuating or heterogeneously hypoattenuating, tex- ture analysis can capture more subtle underlying differences that may reflect important pathologic differences and thereby help predict patient survival.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “A total 489 radiomics features from the whole seg- mented 3D tumor and from the remaining pancreatic parenchyma were extracted to express pancreas and tumor phenotypes of patients with PDAC. Radiomics features used in this study included 478 features from the whole 3D tumor and 11 features from the pancreatic parenchyma not involved by the tumor. The tumor features include 14 first-order statistics of the volumet- ric CT intensities, eight shape features of the target structure, 33 texture features from a gray-level co-occurrence matrix (GLCM) and a gray-level run-length matrix, and 368 texture features from the eight volumes filtered by wavelets.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “Based on the selected radiomics features, a random survival forest was applied for survival prediction in a multivariate dataset with missing variables. Each decision node was divided until three unique deaths (d = 3) remained in the leaf node. Ten thousand trees were built by the training set using the AUC for the split of internal nodes. Each end node stored the survival sta- tus (dead or alive), survival time, and a Cox proportional hazard function of the assigned cases. The survival time and survival status predictions in the validation cohort were determined by majority voting based on the trained trees.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • "The accuracy of survival prediction using only preoperative clinical variables was 0.6785 in terms of the C-index. This value improved to 0.7321 when the 10 selected image features from the tumor phenotype were added and further improved to 0.7414 with additional pancreatic image features. Figure 6 shows the Kaplan-Meier curves for the overall survival prediction of the validation cohort and for the ground-truth prediction.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • "Preoperative CT scans show the global status of pancreatic parenchyma and tumor texture. The overall survival of patients who underwent surgical resection was explored in this study using preoperative CT radiomics features. However, information on different types of therapies (e.g., adjuvant chemotherapy) that each patient received can be combined to analyze the response of each therapy. Even though we found no clear evidence of differences in adjuvant therapy between high-risk and low-risk groups in our dataset, the correlation with detailed types of adjuvant therapy could be further studied with a proper study design. In addition, postoperative clinical parameters can be also considered for better prediction of overall survival.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • "We found that radiomics features extracted from tumors and from the nonneoplastic pancreas can be used to improve survival prediction models of patients who underwent surgery for PDAC. This algorithm could be combined with other pathologic and genetic biomarkers.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “Radiomics is the high throughput extraction of large sets of quantitative data from imaging studies that can be used to characterize healthy and pathological tissues to inform diagnosis and prognosis. Texture analysis, a subtype of radiomics, quantifies gray-level pixels and voxels in a frequency histogram and their spatial relationships to describe lesion heterogeneity within a 2-dimensional region of interest (ROI) or 3-dimensional volume of interest (VOI). Computed tomography (CT) texture analysis has dem- onstrated promise in diagnosing and risk-stratifying patients with PCs. Predictive ability of radiomics models can be enhanced by integrating clinical features in pancreas and non-pancreas tissues.”
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0 
  • "This retrospective analysis demonstrated that machine learn- ing principles applied to radiomics, clinical parameters, and surgical pathology can be used to create a mucinous classifier of PCs. The machine learning mucinous classifiers out- performed the baseline mucinous classifiers on G-mean and AUC scoring metrics, which we believe are the metrics best suited to assess the model quality and potential for useful predictions. Performance was comparable between XGBoost texture feature only and combined models. Shapely additive explanation analysis demonstrated that trends in important model-building variables can be identified. However, overall this remains a challenging task with only moderate performance of the best model.”
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0 
  • “In conclusion, our study demonstrates that machine learning principles can be applied to radiomics data of PCs to help detect mucinous phenotypes. While this information does not obviate the need for other diagnostic testing, it may help risk stratify patients with PCs. We also demonstrate that integration of radiologic and clinical fea- tures with texture feature radiomics data does not improve performance of our mucinous classifier. However, unique radiomic, radiologic, and clinical features were important in building our machine learning mucinous classifiers. These results highlight the potential of machine learning algorithms applied to high-throughput PC radiomics features in helping to detect mucinous cyst phenotype in patients and deserves further study to improve and validate such models.”
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0  
Neuroradiology

  • Lemierre syndrome is a rare and potentially life-threatening complication of bacterial infections that usually affects previously-healthy adolescents and young adults. It most commonly develops in association with a bacterial throat infection, but it may develop in association with an infection involving the ears, salivary glands (parotitis), sinuses, or teeth; or in association with an Epstein-Barr infection.[1] The bacteria typically responsible for infection in Lemierre syndrome is Fusobacterium necrophorum, although a variety of bacteria can be responsible. In people with Lemierre syndrome, the initial infection spreads into tissues and deep spaces within the neck, leading to the formation of an infected blot clot (septic thrombophlebitis), sometimes made up of pus, in the internal jugular vein (the blood vessel that carries blood away from the brain, face, and neck).
    https://rarediseases.info.nih.gov/diseases/6882/lemierre-syndrome
  • “Advanced Lemierre syndrome is a life-threatening condition.The current mortality (death due to the syndrome) is estimated to be between 5% and 18%, depending on the source of the data. However, as the mortality in the pre-antibiotic era reportedly was 90%, the outlook for people with Lemierre syndrome has improved significantly due to advances in antibiotic therapy and high-level intensive care.Receiving the diagnosis as quickly as possible and starting appropriate treatment increases the chance of survival. Severe complications of Lemierre syndrome may include osteomyelitis (bone infection), meningitis, acute respiratory distress syndrome, and septic shock.”
    https://rarediseases.info.nih.gov/diseases/6882/lemierre-syndrome
  • “The identification of thrombophlebitis of the IJ vein is the first hard evidence to suggest Lemierre’s syndrome in many patients. It is likely true that, as with our patient, these imaging studies are ordered in the majority of patients to assess for deep space infections of the neck and not IJ vein thrombophlebitis. Duplex ultrasonography, CT and magnetic resonance imaging have all been used for IJ vein imaging, with CT being most commonly requested in patients with Lemierre’s syndrome. Many authors consider contrast-enhanced CT as the preferred study in this setting as it allows for visualization of surrounding structures and is the most readily available.”
    Lemierre's syndrome.  
    Eilbert W, Singla N.  
    Int J Emerg Med. 2013;6(1):40. 
  • “Lemierre’s syndrome occurs primarily in young, otherwise healthy individuals and is characterized by a history of recent oropharyngeal infection, clinical or radiological evidence of IJ venous thrombosis and anaerobic bacteremia caused primarily by F. necrophorum. This is a rare illness in the modern era of antibiotic therapy, though it has been reported with increasing frequency in the twenty-first century. Lemierre’s syndrome should be suspected in young, healthy patients with prolonged symptoms of pharyngitis followed by symptoms of septicemia or pneumonia, or an atypical lateral neck pain. Diagnosis is often confirmed by the identification of IJ vein thrombophlebitis by an imaging study and growth of anaerobic bacteria on blood culture. Prolonged antibiotic therapy is the cornerstone of treatment, occasionally combined with anticoagulation.”
    Lemierre's syndrome.  
    Eilbert W, Singla N.  
    Int J Emerg Med. 2013;6(1):40. 
Pancreas

  • OBJECTIVE. Pancreatic ductal adenocarcinoma (PDAC) is often a lethal malignancy with limited preoperative predictors of long-term survival. The purpose of this study was to evaluate the prognostic utility of preoperative CT radiomics features in predict- ing postoperative survival of patients with PDAC.  
    RESULTS. The mean age of patients with PDAC was 67 ± 11 (SD) years. The mean tumor size was 3.31 ± 2.55 cm. The 10 most relevant radiomics features showed 82.2% ac- curacy in the classification of high-risk versus low-risk groups. The C-index of survival prediction with clinical parameters alone was 0.6785. The addition of CT radiomics features improved the C-index to 0.7414.  
    CONCLUSION. Addition of CT radiomics features to standard clinical factors improves survival prediction in patients with PDAC.  
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “Tumors are spatially heterogeneous structures that can be characterized at a macro scale, and normal parenchyma can also be affected by the growth of the tumor. Texture analysis using medical images, especially radiomics approaches, is an established technique that describes spatial variations in pixel intensities in images for quantitative assess- ment. Whereas radiologists may qualitatively describe PDAC enhancement patterns as, for example, homogeneously isoattenuating or heterogeneously hypoattenuating, tex- ture analysis can capture more subtle underlying differences that may reflect important pathologic differences and thereby help predict patient survival.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “A total 489 radiomics features from the whole seg- mented 3D tumor and from the remaining pancreatic parenchyma were extracted to express pancreas and tumor phenotypes of patients with PDAC. Radiomics features used in this study included 478 features from the whole 3D tumor and 11 features from the pancreatic parenchyma not involved by the tumor. The tumor features include 14 first-order statistics of the volumet- ric CT intensities, eight shape features of the target structure, 33 texture features from a gray-level co-occurrence matrix (GLCM) and a gray-level run-length matrix, and 368 texture features from the eight volumes filtered by wavelets.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “Based on the selected radiomics features, a random survival forest was applied for survival prediction in a multivariate dataset with missing variables. Each decision node was divided until three unique deaths (d = 3) remained in the leaf node. Ten thousand trees were built by the training set using the AUC for the split of internal nodes. Each end node stored the survival sta- tus (dead or alive), survival time, and a Cox proportional hazard function of the assigned cases. The survival time and survival status predictions in the validation cohort were determined by majority voting based on the trained trees.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • "The accuracy of survival prediction using only preoperative clinical variables was 0.6785 in terms of the C-index. This value improved to 0.7321 when the 10 selected image features from the tumor phenotype were added and further improved to 0.7414 with additional pancreatic image features. Figure 6 shows the Kaplan-Meier curves for the overall survival prediction of the validation cohort and for the ground-truth prediction.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • "Preoperative CT scans show the global status of pancreatic parenchyma and tumor texture. The overall survival of patients who underwent surgical resection was explored in this study using preoperative CT radiomics features. However, information on different types of therapies (e.g., adjuvant chemotherapy) that each patient received can be combined to analyze the response of each therapy. Even though we found no clear evidence of differences in adjuvant therapy between high-risk and low-risk groups in our dataset, the correlation with detailed types of adjuvant therapy could be further studied with a proper study design. In addition, postoperative clinical parameters can be also considered for better prediction of overall survival.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • "We found that radiomics features extracted from tumors and from the nonneoplastic pancreas can be used to improve survival prediction models of patients who underwent surgery for PDAC. This algorithm could be combined with other pathologic and genetic biomarkers.”
    CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112

  • CT Radiomics–Based Preoperative Survival Prediction in Patients With Pancreatic Ductal Adenocarcinoma  
    Seyoun Park et al.
    AJR 2021; 217:1104–1112
  • “Radiomics is the high throughput extraction of large sets of quantitative data from imaging studies that can be used to characterize healthy and pathological tissues to inform diagnosis and prognosis. Texture analysis, a subtype of radiomics, quantifies gray-level pixels and voxels in a frequency histogram and their spatial relationships to describe lesion heterogeneity within a 2-dimensional region of interest (ROI) or 3-dimensional volume of interest (VOI). Computed tomography (CT) texture analysis has dem- onstrated promise in diagnosing and risk-stratifying patients with PCs. Predictive ability of radiomics models can be enhanced by integrating clinical features in pancreas and non-pancreas tissues.”
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0 
  • "This retrospective analysis demonstrated that machine learn- ing principles applied to radiomics, clinical parameters, and surgical pathology can be used to create a mucinous classifier of PCs. The machine learning mucinous classifiers out- performed the baseline mucinous classifiers on G-mean and AUC scoring metrics, which we believe are the metrics best suited to assess the model quality and potential for useful predictions. Performance was comparable between XGBoost texture feature only and combined models. Shapely additive explanation analysis demonstrated that trends in important model-building variables can be identified. However, overall this remains a challenging task with only moderate performance of the best model.”
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0 
  • “In conclusion, our study demonstrates that machine learning principles can be applied to radiomics data of PCs to help detect mucinous phenotypes. While this information does not obviate the need for other diagnostic testing, it may help risk stratify patients with PCs. We also demonstrate that integration of radiologic and clinical fea- tures with texture feature radiomics data does not improve performance of our mucinous classifier. However, unique radiomic, radiologic, and clinical features were important in building our machine learning mucinous classifiers. These results highlight the potential of machine learning algorithms applied to high-throughput PC radiomics features in helping to detect mucinous cyst phenotype in patients and deserves further study to improve and validate such models.”
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0  
  • “In this paper, we consider a partially supervised setting, where cheap image-level annotations are provided for all the train- ing data, and the costly per-voxel annotations are only available for a subset of them. We propose an Inductive Attention Guidance Network (IAG-Net) to jointly learn a global image-level classifier for normal/PDAC classification and a local voxel-level classifier for semi-supervised PDAC segmentation. We instantiate both the global and the local classifiers by multiple instance learning (MIL), where the attention guidance, indicating roughly where the PDAC regions are, is the key to bridging them: For global MIL based normal/PDAC classification, attention serves as a weight for each instance (voxel) during MIL pooling, which eliminates the distraction from the background; For local MIL based semi-supervised PDAC segmentation, the attention guidance is inductive, which not only provides bag-level pseudo-labels to training data without per-voxel annotations for MIL training, but also acts as a proxy of an instance-level classifier.”
    Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 


  • Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 

  • Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 
  • “This paper addresses the problem of PDAC prediction i.e., normal/PDAC classification and PDAC segmentation under the partially supervised setting. We present an Inductive Attention Guidance (IAG) strategy for learning a global image-level clas- sifier for normal/PDAC segmentation and a local instance-level classifier for semi-supervised PDAC segmentation, which enjoys the advantages of bridging the MIL-based global and local classifiers. We showed empirically on the JHMI dataset the superiority of the proposed IAG-Net for PDAC predic- tion, which is helpful to computer-assisted clinical diagnoses. Additionally, we verified the generality of IAG-Net on the pancreas tumor segmentation dataset in MSD challenge.”  
    Learning Inductive Attention Guidance for Partially Supervised Pancreatic Ductal Adenocarcinoma Prediction  
    Yan Wang , Peng Tang, Yuyin Zhou , Wei Shen, Elliot K. Fishman , Alan L. Yuille,  
    IEEE TRANSACTIONS ON MEDICAL IMAGING, VOL. 40, NO. 10, OCTOBER 2021 
  • "This has led to an increased interest in radiomics, a high-throughput extraction of comprehensible data from standard of care images. Radiomics can be used as a diagnostic and prognostic tool in personalized medicine. It utilizes quantitative image analysis to extract features in conjunction with machine learning and artificial intelligence (AI) methods like support vector machines, random forest, and convolutional neural network for feature se- lection and classification. Selected features can then serve as imaging biomarkers to predict high-risk PCLs. Radiomics studies conducted heretofore on PCLs have shown promising results.”
    Radiomics in stratification of pancreatic cystic lesions: Machine learning in action  
    Vipin Dalala et al.
    Cancer Letters,Volume 469,2020,Pages 228-237
  • "IPMNs and MCNs are the only radiographically identifiable precursors of pancreatic cancer. Consequently, accurate assessment of the malignant potential of these cystic lesions may allow early detection of resectable PCLs prior to oncogenesis. The latest guidelines propose a practical approach for their management and surveillance, yet the clinical management of these mucinous cystic lesions remains challenging. The variable risk of malignant transformation combined with elevated risks associated with pancreatic surgery have led to conflicting recommendations for the management of mucinous cystic lesions.”
    Radiomics in stratification of pancreatic cystic lesions: Machine learning in action  
    Vipin Dalala et al.
    Cancer Letters,Volume 469,2020,Pages 228-237
  • "Although only a few studies describing the use of radiomics in risk stratification of PCLs have been published, these studies have demonstrated that radiomics can be utilized to non-invasively discriminate between low-risk and high-risk PCLs before resection. This cost-effective approach would enable us to accurately recommend lifesaving surgery for individuals with malignant cysts and spare those with benign lesions the morbidity, mortality and high costs associated with pancreatic surgeries. Consequently, more studies are warranted to develop these imaging biomarkers which can be used to differentiate between benign and malignant PCLs.”
    Radiomics in stratification of pancreatic cystic lesions: Machine learning in action  
    Vipin Dalala et al.
    Cancer Letters,Volume 469,2020,Pages 228-237
  • “Pancreatic cysts are common and often pose a management dilemma, because some cysts are precancerous, whereas others have little risk of developing into invasive cancers. We used supervised machine learning techniques to develop a comprehensive test, CompCyst, to guide the management of patients with pancreatic cysts. The test is based on selected clinical features, imaging characteristics, and cyst fluid genetic and biochemical markers. Using data from 436 patients with pancreatic cysts, we trained CompCyst to classify patients as those who required surgery, those who should be routinely monitored, and those who did not require further surveillance. We then tested CompCyst in an independent cohort of 426 patients, with histopathology used as the gold standard. We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • “We found that clinical management informed by the CompCyst test was more accurate than the management dictated by conventional clinical and imaging criteria alone. Application of the CompCyst test would have spared surgery in more than half of the patients who underwent unnecessary resection of their cysts. CompCyst therefore has the potential to reduce the patient morbidity and economic costs associated with current standard-of-care pancreatic cyst management practices.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • “Two dilemmas make pancreatic cyst clinical management challenging. First, it is difficult to differentiate IPMNs and MCNs, collectively termed “mucin-producing cysts,” from cysts that have no malignant potential and do not require any follow-up. Second, it can be difficult to differentiate patients with mucin-producing cysts that harbor early invasive cancer or high-grade dysplasia from patients with less advanced mucin-producing cysts. Surgery is recommended for patients with advanced cysts, whereas intermittent surveillance with imaging, rather than surgery, is considered appropriate for patients with less advanced cysts. Currently available clinical tools, however, are imperfect at assigning the most appropriate management strategies for patients with cysts. This is highlighted by the fact that 25% of cyst patients who undergo surgical resection have a pancreatic cyst with no malignant potential, and up to 78% of mucin-producing cysts referred for surgical resection are ultimately found not to be advanced, that is, they do not harbor high-grade dysplasia or cancer.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772

  • A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772

  • A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772

  • A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • “In conclusion, the use of a comprehensive test that evaluates clinical, imaging, and molecular features is imperfect but appears to offer substantial improvements over standard-of-care management of patients with pancreatic cysts. CompCyst does not replace conventional clinical tools. Instead, it contributes additional information, allowing clinicians to make more informed decisions. How and when tests like CompCyst can be implemented in routine clinical settings remains to be determined, but our results represent the next stage of research required for such implementation. An important next test of the markers presented here could be their validation in a follow-up, prospective study.”
    A multimodality test to guide the management of patients with a pancreatic cyst.  
    Springer S, Masica DL, Dal Molin M, et al.  
    Sci Transl Med. 2019;11(501):eaav4772. doi:10.1126/scitranslmed.aav4772
  • “Results: Twenty-five (78%) patients presented with symptoms and 8 (25%) patients had abnormal serum biochemical values. Mean MCN maximum dimensions were 48 9 45 9 45 mm with a mean volume of 169 mL. MCN were located in the tail (n = 18), body (n = 10), neck (n = 2), and (head = 2); 30 (93.5%) MCN were encapsulated, 3 (9%) had calcifications, 4 (12%) showed enhancing nodules, 9 (28%) had enhancing septations, and 5 (15%) had main pancreatic duct dilation. Associated chronic pancreatitis was observed in 4 (12%) patients. The only predictors for high-grade dysplasia/carcinoma were MCN size and volume. Using a cut-off size greater than 8.5 cm, the specificity and sensitivity for high-grade dysplasia/carcinoma were 97 and 60%, respectively (p = 0.003; OR 81, 95% CI 3.9–1655.8). Mean MCN growth rate was estimated at 4.2 mm/year with a doubling time of 8.23 years.”
    Mucinous cystic neoplasms of the pancreas: high-resolution cross-sectional imaging features with clinico-pathologic correlation  
    Alejandro Garces-Descovich et al.
    Abdom Radiol (2018) 43:1413–1422
  • "MCN size (> 8.5 cm) and volume are the only features on MDCT/MR imaging that correlate with high-grade dysplasia/carcinoma. The average growth rate for MCNs is slow at approximately 4 mm per year.”  
    Mucinous cystic neoplasms of the pancreas: high-resolution cross-sectional imaging features with clinico-pathologic correlation  
    Alejandro Garces-Descovich et al.
    Abdom Radiol (2018) 43:1413–1422
  • "Mucinous cystic neoplasms (MCN) of the pancreas are uncommon tumors that are nearly exclusively seen in middle-aged females. Although the vast majority of MCN are benign at time of diagnosis, they are considered pre-malignant lesions that may become dysplastic and malignant over time. To the best of our knowledge, the exact timeline for this progression is unknown. Needless to say, the ability to predict non-invasively the pathological subtype of MCN can have important advantages and implications. Firstly, biopsy of MCN is prone to sample bias as the epithelial lining of the cyst may be normal in one location but dysplastic or frankly malignant in others. Secondly, MCN with low-grade dysplasia may be treated conservatively with observation rather than surgery, especially in elderly patients with co- morbidities. Lastly, indications for high-grade dysplasia or carcinoma may trigger immediate surgical resection.”
    Mucinous cystic neoplasms of the pancreas: high-resolution cross-sectional imaging features with clinico-pathologic correlation  
    Alejandro Garces-Descovich et al.
    Abdom Radiol (2018) 43:1413–1422
  • “In our series, all patients were women with a mean age of 45 years. Indeed, MCN is referred to as the ‘mother cyst’ and the previously reported distribution of MCN by gender is 89–99.7% female with a reported mean age at time of diagnosis of 48 years (range, 17–78 years). Presenting clinical signs and symptoms along with serologic biochemical values were also evaluated and correlated with pathology. Although in our cohort 75% of patients presented with at least one symptom, we did not identify any correlation between clinical symptoma- tology with the presence of high-grade dysplasia/carci- noma.”
    Mucinous cystic neoplasms of the pancreas: high-resolution cross-sectional imaging features with clinico-pathologic correlation  
    Alejandro Garces-Descovich et al.
    Abdom Radiol (2018) 43:1413–1422
  • "In conclusion, MCN size (> 8.5 cm) and volume are the only features on MDCT/MR imaging that correlates with high-grade dysplasia/carcinoma. Moreover, no clinical symptoms, biochemical abnormalities, or pre-operative cyst features previously described as potential predictors high-grade dysplasia/carcinoma could be reproduced. The average growth rate for MCNs is slow at approximately 4 mm per year.”
    Mucinous cystic neoplasms of the pancreas: high-resolution cross-sectional imaging features with clinico-pathologic correlation  
    Alejandro Garces-Descovich et al.
    Abdom Radiol (2018) 43:1413–1422
  • “Mucinous cystic neoplasms (MCN) of the pancreas are rare, low-grade tumors that occur predominantly in middle-aged women . They are reported to be maligant in about 6–27% of cases. Their most characteristic histopathological finding is the combination of mucin-producing epithelium supported by characteristic ovarian-like stroma that is not found in other pancreatic neoplasms. Furthermore, they usually are com- posed of large (> 2 cm) unilocular or multilocular macrocysts devoid of communication between the cyst and the pancreatic ductal system, and the presence of a fibrous capsule. All MCNs have the potential to transform into an invasive carcinoma, hence the necessity to resect them in their totality.”  
    Mucinous cystic neoplasms of the pancreas: high-resolution cross-sectional imaging features with clinico-pathologic correlation  
    Alejandro Garces-Descovich et al.
    Abdom Radiol (2018) 43:1413–1422
  • Cystic Pancreas Lesions: Mimics
    - Solid and Pseudopapillary Epithelial Neoplasms 
    - Cystic Features of Pancreatic Ductal Adenocarcinoma 
    - Cystic Neuroendocrine Tumor 
  • "SCNs typically are described as having a honey- comb or multilocular appearance with or without a central scar. However, there can be variations in the morphologic appearance with polycystic, oligocystic, and solid patterns described. Microcystic morphology is more common in SCNs. The classic imaging features are a lobulated external contour and central scar with stellate calcification. SCNs rarely demonstrate peripheral enhancing capsule or mural nodules.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “Lymphoepithelial cysts are rare cysts lined with squamous epithelium and surrounded by lymphoid tissue. They typically affect men who are middle-aged or older and are exophytic with a higher CT attenuation compared with SCNs and MCNs. The reference standard for diagnosis is excision.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “IPMNs are cystic neoplasms with variable degree of malignant potential. They may evolve into dysplasia or invasive carcinoma and are associated with a higher risk for the development of PDAC in the gland separate from the IPMN sites. The rate of progression increases with time. Low-risk IPMNs have an approximately 8% chance of progression, whereas higher risk IPMNs have an approximately 25% chance of progression to PDAC in 10 years. Even presumed low- risk BD-IPMNs may demonstrate growth after 5 years.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • "MCN occur almost exclusively in women and more commonly are found in the pancreatic tail. MCNs are oval or round and can show septations, cyst wall calcifications, enhancing capsules, and occasionally mural nodules. MCNs typically do not cause dilatation of the biliary or pancreatic ductal system but can be associated with distal pancreatic atrophy. They may be associated with lymphadenopathy but generally are not associated with peripancreatic fat infiltration or vascular involvement.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • "Cysts with at least 2 high-risk features (size >3 cm, dilated MPD or solid component) should have EUS-FNA. After reassuring EUS- FNA, MR imaging surveillance is recommended after 1 year and then every 2 years; substantial changes in the cyst by imaging should result in repeat EUS-FNA. Cysts with solid components and a dilated MPD or concerning EUS-FNA should be offered surgery. After excision of cancer or a cystic/mucin-producing neoplasm with dysplasia, the residual pancreas should be examined using MR imaging surveillance every 2 years.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “A  of carcinoembryonic antigen (CEA) level greater than or equal to 192 ng/mL and molecular analysis, including DNA concentration, K-RAS mutations, and allelic imbalances, improves sensitivity in diagnosing mucinous from nonmucinous neoplasms, although CEA cutoff levels may be specific to the individual laboratory. CA 19-9 analysis of cyst aspirate is not useful. Large amounts of PC fluid DNA, high-  amplitude mutations, and specific mutation acqui- sition sequences are predictors of malignancy.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • "Genes associated with IPMNs include KRAS, GNAS, RNF43, TP53, PIK3CA, PTEN, CDKN2A, and SMAD4.46 MCNs are associated with genetic alterations in KRAS, RNF43, TP53, PIK3CA, PTEN, CDKN2A, and SMAD4. SCNs have a typical CEA fluid analysis of less than 5 ng/mL and low viscosity and are associated with mutations in the VHL gene. Fluid viscosity can be used to differentiate between mucinous and nonmucinous cysts.The string sign is measured by the maximal length of mucus string between the thumb and index finger of the examiner; a positive string sign is if the mucus measures at least 3 mm.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “Incidental PCs commonly are encountered in a radiology practice. Some cystic masses of the pancreas, in particular pseudocysts, usually can be characterized accurately and adequately by a combination of imaging, history, and follow-up. Other PCs require further evaluation with EUS with FNA. Because some have malignant potential, many PCs require clinical and imaging follow-up. There are several available societal guidelines to help plan patient follow-up, with recent updates. The care of patients with PCs ideally is a multidisciplinary effort among radiologists, pathologists, surgeons, and gastroenterologists for optimal patient management.”  
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “Although typically solid and hyperenhancing, pancreatic neuroendocrine tumors can be mixed cystic and solid and, rarely, almost entirely cystic with a thick hyperenhancing rim or mural nodularity. These tumors can be multifocal, and, although they usually are sporadic, they can be associated with neurofibromatosis 1, multiple endocrine neoplasia type 1, or VHL disease. There is a relatively high degree of metastatic disease, either to lymph nodes or liver.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “Although the classic appearance of PDAC is a solid, infiltrating mass, it may develop cystic features , including large duct cysts, neoplastic mucinous cysts, colloid carcinomas, and degenerative cystic change. An obstructing mass can cause retention cysts or pseudocysts from pancreatitis There rarely can be a combination of these processes with the same patient, that is, areas of cystic degeneration/necrosis, as well as cystic changes related to secondary pancreatitis. Clear ductal obstruction should raise concern for PDAC.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • “SPENs are relatively rare low-grade malignant tumors that typically affect young women. These tumors can be solid, cystic, or mixed and frequently develop internal hemorrhage. A well- defined thick enhancing capsule is typical. These usually are large (average 9 cm) and more often in the tail.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • - Imaging alone cannot always differentiate benign pancreatic cysts from pancreatic cysts with malignant potential. 
    - Small indeterminate pancreatic cysts need to be followed-up, since invasive testing and re- sections are typically reserved for larger or growing cysts or definitively malignant cysts. 
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629
  • “MCNs occur almost exclusively in women and more commonly are found in the pancreatic tail. MCNs are oval or round and can show septations, cyst wall calcifications, enhancing capsules, and occasionally mural nodules. MCNs typically do not cause dilatation of the biliary or pancreatic ductal system but can be associated with distal pancreatic atrophy. They may be associated with lymphadenopathy but generally are not associated with peripancreatic fat infiltration or vascular involvement.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.  
    Radiol Clin N Am 59 (2021) 617–629 
  • Cystic Pancreatic Lesions
    - Pancreatic Pseudocyst
    - Serous cystadenoma
    - Lymphoepithelial Cyst 
    - IPMN
    - MCN (Mucinous Cystic Neoplasm)
    - Solid and Pseudopapillary Epithelial Neoplasms (SPEN)
    - Cystic Features of Pancreatic Ductal Adenocarcinoma 
    - Cystic Neuroendocrine Tumor 
  • “Predictors of high-grade dysplasia (MCN) include size greater 8.5 cm.”  
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.  
    Radiol Clin N Am 59 (2021) 617–629 
  • Summary of guidelines for follow-up of incidental pancreatic cysts 
  • MCN vs SCN using EUS
  • “Mucinous cystic neoplasms (MCN) and serous cystic neoplasms (SCN) account for a large portion of solitary pancreatic cystic neoplasms (PCN). In this study we implemented a convolutional neural network (CNN) model using ResNet50 to differentiate between MCN and SCN. The training data were collected retrospectively from 59 MCN and 49 SCN patients from two different hospitals. Data augmentation was used to enhance the size and quality of training datasets. Fine-tuning training approaches were utilized by adopting the pre-trained model from transfer learning while training selected layers. Testing of the network was conducted by varying the endoscopic ultrasonography (EUS) image sizes and positions to evaluate the network performance for differentiation. The proposed network model achieved up to 82.75% accuracy and a 0.88 (95% CI: 0.817–0.930) area under curve (AUC) score.”
    Deep Learning-Based Differentiation between Mucinous Cystic Neoplasm and Serous Cystic Neoplasm in the Pancreas Using Endoscopic Ultrasonography  
    Leang Sim Nguon et al.
    Diagnostics 2021, 11, 1052. https://doi.org/10.3390/diagnostics11061052 
  • “This study aimed to investigate the diagnostic ability of carcinoembryonic antigen (CEA), cytology, and artificial intelligence (AI) by deep learning using cyst fluid in differentiating malignant from benign cystic lesions. We retrospectively reviewed 85 patients who underwent pancreatic cyst fluid analysis of surgical specimens or endoscopic ultrasound-guided fine-needle aspiration specimens. AI using deep learning was used to construct a diagnostic algorithm. CEA, carbohydrate antigen 19-9, carbohydrate antigen 125, amylase in the cyst fluid, sex, cyst location, connection of the pancreatic duct and cyst, type of cyst, and cytology were keyed into the AI algorithm, and the malignant predictive value of the output was calculated. Area under receiver-operating characteristics curves for the diagnostic ability of malignant cystic lesions were 0.719 (CEA), 0.739 (cytology), and 0.966 (AI). In the diagnostic ability of malignant cystic lesions, sensitivity, specificity, and accuracy of AI were 95.7%, 91.9%, and 92.9%, respectively. AI sensitivity was higher than that of CEA (60.9%, p = 0.021) and cytology (47.8%, p = 0.001). AI accuracy was also higher than CEA (71.8%, p < 0.001) and cytology (85.9%, p = 0.210). AI may improve the diagnostic ability in differentiating malignant from benign pancreatic cystic lesions.”
    Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions  
    Yusuke Kurita et al.
    Scientific Reports | (2019) 9:6893 
  • "Although cytology had excellent specificity, it has a limited role because of its lack of sensitivity in previous studies30–32. In the present study, the sensitivity of cytology in differentiating malignant from benign cystic lesions was 47.8%. Thus, we constructed AI using deep learning algorithm for differentiating malignant from benign pancreatic cystic lesions based on the analysis of pancreatic cyst fluid and clinical data.”  
    Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions  
    Yusuke Kurita et al.
    Scientific Reports | (2019) 9:6893 
  • "In this study, AI using deep learning analyzed pancreatic cyst fluid and clinical data. By using this deep learning method, AI learns the characteristics of malignant cystic lesions by combining cyst fluid analysis and clinical data, and AI can possibly exclude the bias generated by human judgment. Although it is difficult for clinicians to diagnose malignant pancreatic cystic lesions by cyst fluid analysis and clinical data, AI using deep learning achieved adequate diagnostic ability in differentiating malignant from benign cystic lesions compared to cyst fluid analysis such as CEA and cytology. AI and CEA were also significant factor in the multivariate analysis of malignant cystic lesion. Specifically, although it is generally a problem that cytology diagnosis has low sensitivity, AI using deep learning achieved high sensitivity (95.7%).”
    Diagnostic ability of artificial intelligence using deep learning analysis of cyst fluid in differentiating malignant from benign pancreatic cystic lesions  
    Yusuke Kurita et al.
    Scientific Reports | (2019) 9:6893 
  • "Chakraborty et al. utilized radiomics features extracted from pre- surgical CT images, as markers for assessment of malignancy risk of BD- IPMNs. Similar to the previous studies, they categorized their cohort of 103 patients into low-risk and high-risk IPMNs based on final pathological findings after cyst resection. They extracted four new radio- graphically inspired features (enhanced boundary fraction, enhanced inside fraction, filled largest connected component fraction and average weighted eccentricity), along with intensity and orientation-based texture features from the CT images.”
    Radiomics in stratification of pancreatic cystic lesions: Machine learning in action  
    Vipin Dalala et al.
    Cancer Letters,Volume 469,2020,Pages 228-237
  • Background and aims: To successfully implement imaging-based pancreatic cancer (PC) surveillance, it is key to understand the timeline and morphological features of neoplastic progression. We aimed to investigate the progression to neoplasia from serial prediagnostic pancreatic imaging tests in high-risk individuals, and identify factors associated with successful early detection. Methods We retrospectively examined the development of pancreatic abnormalities in high-risk individuals who were diagnosed with PC and/or underwent pancreatic surgery in 16 international surveillance programs.
    Conclusion: Nearly half of high-risk individuals developing high-grade dysplasia or PC have no prior lesions detected by imaging, yet present at an advanced stage. Progression can occur before the next scheduled annual examination. More sensitive diagnostic tools or a different management strategy for rapidly-growing cysts are needed.
  • Conclusion: Nearly half of high-risk individuals developing high-grade dysplasia or PC have no prior lesions detected by imaging, yet present at an advanced stage. Progression can occur before the next scheduled annual examination. More sensitive diagnostic tools or a different management strategy for rapidly-growing cysts are needed.
    Timeline of development of pancreatic cancer and implications for successful early detection in high-risk individual
    Overbeek KA et al
    On behalf of the International Cancer of the Pancreas Screening Consortium  Gastroenterology (2021), doi: https://doi.org/10.1053/j.gastro.2021.10.014.
  • Results: Of 2552 high-risk individuals under surveillance, 28 (1%) developed neoplastic progression to PC or high-grade dysplasia during follow-up (median 29 months after baseline, IQR 40). 46% (13/28) presented with a new lesion (median size 15 mm, range 7-57), a median of 11 months (IQR 8, range 3-17) after a prior examination, by which time 77% (10/13) had progressed beyond the pancreas. The other 54% (15/28) had neoplastic progression in a previously detected lesion (12 originally cystic, 2 indeterminate, 1 solid); 11 (73%) had PC progressed beyond the pancreas. The 12 patients with cysts had been followed for 21 months (IQR 15) and had a median growth of 5 mm/year (IQR 8). Successful early detection (as high-grade dysplasia or PC confined to the pancreas) was associated with resection of cystic lesions (versus solid or indeterminate lesions, OR 5.388, 95%CI 1.525-19.029) and small lesions (OR 0.890/mm, 95%CI 0.812-0.976).  
    Timeline of development of pancreatic cancer and implications for successful early detection in high-risk individual
    Overbeek KA et al
    On behalf of the International Cancer of the Pancreas Screening Consortium  Gastroenterology (2021), doi: https://doi.org/10.1053/j.gastro.2021.10.014.
  • “In conclusion, in the framework of an imaging-based PC surveillance research program in high-risk individuals, almost half of the cases developed a neoplastic lesion without prior signs on imaging, and by the time of detection and/or surgical treatment, the majority had already progressed beyond an early stage (T1N0M0). Progression to advanced PC therefore can occur before the next annual surveillance examination, posing the question if in certain (selected) high-risk individuals, shorter surveillance intervals are required. The other half developed from a preceding lesion that was most often cystic, but also in this group timely identification of malignant transformation was challenging. Importantly, although progressing neoplastic cysts displayed fast growth, the presence of worrisome features could not reliably differentiate cysts with neoplastic progression from those without. The implementation of novel tools, such as improved imaging techniques and the artificial analysis of images and, most likely more promising, new and accurate biomarkers, are urgently needed to improve the outcome of PC surveillance research programs in high-risk individuals and to detect high-grade dysplasia and early cancer.”
    Timeline of development of pancreatic cancer and implications for successful early detection in high-risk individual
    Overbeek KA et al
    Gastroenterology (2021), doi: https://doi.org/10.1053/j.gastro.2021.10.014.
  • Purpose: Current diagnostic and treatment modalities for pancreatic cysts (PCs) are invasive and are associated with patient morbidity. The purpose of this study is to develop and evaluate machine learning algorithms to delineate mucinous from non-mucinous PCs using non-invasive CT-based radiomics.
    Conclusion: Machine learning principles can be applied to PC texture features to create a mucinous phenotype classifier. Model performance did not improve with the combined model. However, specific radiomic, radiologic, and clinical features most predictive in our models can be identified using SHAP analysis.  
    Machine learning principles applied to CT radiomics to predict mucinous pancreatic cysts  
    Adam M. Awe et al.
    Abdominal Radiology https://doi.org/10.1007/s00261-021-03289-0  
Small Bowel

  • Gangliocytic paraganglioma (GP) is an extremely rare benign tumor that commonly arises from the second part of the duodenum. Since GP exhibit neither prominent mitotic activity nor Ki-67 immunoreactivity, this tumor is often misdiagnosed as neuroendocrine tumor (NET) G1 (carcinoid tumor).  
    Gangliocytic paraganglioma: a multi-institutional retrospective study in Japan.
    Okubo, Y et al.  
    BMC Cancer 15, 269 (2015). https://doi.org/10.1186/s12885-015-1308-8 
  • “Gangliocytic paraganglioma is a rare neoplasm that usually occurs in the second portion of the duodenum. It is currently classified as a benign neoplasm, but there are several reports of lymph node and distant metastasis, and there is no validated predictive factor for metastasis. Furthermore, diagnosis with biopsy specimens is sometimes difficult. Careful and complete evaluation with multidepartmental cooperation should be undertaken to accurately diagnose the neoplasm. It is important to remember the possibility of lymph node and distant metastasis.”
    Duodenal Gangliocytic Paraganglioma With Lymph Node Metastasis  
    Hyung Kyu Park, MD; Hye Seung Han, MD, PhD
    Arch Pathol Lab Med (2016) 140 (1): 94–98. 
  • Merkel cell carcinoma (MCC) is a rare but highly aggressive skin cancer with neuroendocrine features. MCC pathogenesis is associated with either the presence of Merkel cell polyomavirus or chronic exposure to ultraviolet light (UV), which can cause a characteristic pattern of multiple DNA mutations. Notably, in the Northern hemisphere, the majority of MCC cases are of viral aetiology; by contrast, in areas with high UV exposure, UV-mediated carcinogenesis is predominant. The two aetiologies share similar clinical, histopathological and prognostic characteristics. MCC presents with a solitary cutaneous or subcutaneous nodule, most frequently in sun-exposed areas. In fact, UV exposure is probably involved in both viral-mediated and non-viral-mediated carcinogenesis, by contributing to immunosuppression or DNA damage, respectively.
    Merkel cell carcinoma.  
    Becker, J., Stang, A., DeCaprio, J. et al.  
    Nat Rev Dis Primers 3, 17077 (2017). https://doi.org/10.1038/nrdp.2017.77
Vascular

  • Vasculitis is a systemic disease characterized by non-infectious inflammation of the blood vessels. The cause can be primary (idiopathic) or secondary to an underlying disease. The precise pathophysiology of idiopathic vasculitides is unknown. Therefore, classification is based on vessel size—large, medium, small, and variable. Large vessel vasculitis (LVV) predominantly involves the large vessels (aorta and its main branches) but can also affect medium- or small-sized vessels. In variable-vessel vasculitis (VVV), any vessel can be affected, and no type of vessel predominates.  
    Multimodality Imaging of Large Vessel Vasculitis
    Ayaz Aghayev
    https://doi.org/10.2214/AJR.21.26150
  • Primary Vasculitides: Categories
    - large vessel vasculitis (LVV): affecting predominantly large blood vessels (aorta and its major branches)
    --- Takayasu arteritis (TA)
    --- giant cell arteritis (GCA)
    - medium vessel vasculitis (MVV): affecting predominantly medium blood vessels (main visceral arteries and their branches) 
    --- polyarteritis nodosa (PAN)
    --- Kawasaki disease (KD)
    - small vessel vasculitis (SVV): affecting predominantly small blood vessels (intraparenchymal arteries, arterioles, capillaries, and venules)
    --- antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)
    ----- microscopic polyangiitis (MPA)
    ----- eosinophilic granulomatosis with polyangiitis (EGPA) (formerly known as Churg-Strauss syndrome)
    ----- granulomatosis with polyangiitis (GPA) (formerly known as Wegener granulomatosis)
    --- immune complex SVV
    ----- anti-glomerular basement membrane (anti-GBM) disease (Goodpasture syndrome)
    ----- cryoglobulinaemic vasculitis (CV)
    ----- IgA vasculitis (IgAV) (Henoch-Schönlein purpura)
    ----- hypocomplementaemic urticarial vasculitis (HUV) (anti-C1q vasculitis)
  • Primary Vasculitides: Categories
    - variable vessel vasculitis (VVV): affecting no predominant type of vessel and can affect vessels of any size and type
    --- Cogan syndrome (CS)
    --- Behçet syndrome (BS)
    - single-organ vasculitis (SOV): affecting vessels of any size in only a single organ
    --- cutaneous leukocytoclastic angiitis
    --- cutaneous arteritis
    --- primary central nervous system vasculitis (see central nervous system vasculitides)
    --- isolated aortitis (see aortitis)
    --- others (e.g. idiopathic, pauci-immune pulmonary capillaritis)
  • Secondary vasculitides: facts
    - vasculitis associated with systemic disease
    --- lupus vasculitis
    --- rheumatoid vasculitis (see rheumatoid pulmonary vasculitis)
    --- sarcoid vasculitis
    --- others (eg. Sneddon syndrome)
    - vasculitis associated with probable etiology
    --- hepatitis C virus-associated cryoglobulinaemic vasculitis
    --- hepatitis B virus-associated vasculitis
    --- syphilis-associated aortitis
    --- drug-associated immune complex vasculitis
    --- drug-associated ANCA-associated vasculitis (e.g. propylthiouracil 2) 
    --- cancer-associated vasculitis
    --- others (e.g. varicella zoster virus-associated vasculitis)
  • Giant Cell Arteritis: Facts
    Giant cell arteritis, the most common form of vasculitis in the elderly, is characterized by granulomatous inflammation of arteries, which can lead to serious, life-threatening condi- tions including aortic aneurysms, ruptures, and dissections as well as blindness. Since GCA can be treated by immunosuppressant therapy, such as corticosteroids, early diagnosis and treatment may reduce the risk of serious disability and morbidity. While temporal artery biopsy is considered the gold standard to diagnosis giant cell arteritis, it is intrusive with inherent risks as well as unreliable due to tissue sampling. Imaging studies, such as computerized tomography, are nonintrusive and have been shown to identify vasculitis including giant cell arteritis.
    Giant cell arteritis: A case report and review of literature 
    Matthew A. Crain et al.
    Radiology Case Reports 16 (2021) 3734–3738 
  • “The diagnostic criteria per American College of Rheumatology (ACR) requires at least 3 of the following: age >50 years, new onset localized headache, temporal artery tenderness or reduced pulsation, elevated erythrocyte sedimentation rate ≥50 mm/hour, and abnormal arterial biopsy (demonstrating vasculitis with predominantly mononuclear cell infiltration, granulomatous inflammation or evidence of giant cells).”
    Thoracic imaging finding of rheumatic diseases.  
    Gul M et al.  
    J Thorac Dis. 2020;12(9):5110-5118. 
  • "Thoracic complications include arm claudication or subclavian steal syndrome if the subclavian artery is affected. Involvement of the thoracic or abdominal aorta can also cause aortic valve regurgitation, aortic aneurysm and aortic dissection. In addition, Giant cell arteritis is associated with increased risk of myocardial infarction, stroke, and peripheral vascular disease.”
    Thoracic imaging finding of rheumatic diseases.  
    Gul M et al.  
    J Thorac Dis. 2020;12(9):5110-5118. 
  • "TA is a chronic, large vessel granulomatous disease that predominantly affects the aorta and its branches, leading to luminal stenosis and aneurysms in these vessels. It can also affect the coronary and pulmonary arteries. This disease is more common in women, particularly in Asian women, and often presents in patients under the age of 40. Also known as the “pulseless disease”, clinical findings in TA may include weak or absent peripheral pulses, arterial bruits, carotidynia, angina, claudication and >10 mmHg discrepancy in blood pressure between upper limbs.”
    Thoracic imaging finding of rheumatic diseases.  
    Gul M et al.  
    J Thorac Dis. 2020;12(9):5110-5118. 
  • "The classic manifestation of TA on CT angiography is concentric mural thickening, that is several millimetres wide, of the involved arteries. Other imaging options include Positron emission tomography (PET), which in combination with CT (PET-CT) or MR (PET-MR), can be used to evaluate for possible large-vessel vasculitis. The “hot” segments of the artery (i.e., those with increased standardized uptake values) can help diagnose large vessel vasculitis.”
    Thoracic imaging finding of rheumatic diseases.  
    Gul M et al.  
    J Thorac Dis. 2020;12(9):5110-5118. 
  • “CTA can evaluate mural thickening, stenosis, and aneurysm of the aorta and branch vessels. In one study, CTA was shown to have a sensitivity of 73% and specificity of 78% to diagnose GCA. CTA has also been used in the diagnosis of TAK with high accuracy. Advantages of CT include its non-invasiveness in comparison to conventional catheter-based angiography and the ability to detect structural lesions with a higher resolution and shorter scanning time than MRA, allowing for more arterial regions to be evaluated in one session. Additionally, CTA is a preferred non-invasive imaging modality to monitor changes in aortic aneurysm morphology over time.”
    “The Role of Vascular Imaging to Advance Clinical Care and Research in Large-Vessel Vasculitis.”  
    Quinn, Kaitlin A, and Peter C Grayson.  
    Current treatment options in rheumatology vol. 5,1 (2019): 20-35
  • “Large vessel vasculitis (LVV) is the most common form of primary vasculitis comprising of giant cell arteritis (GCA), Takayasu’s arteritis (TAK) and idiopathic aortitis. Early diagnosis and treatment of LVV are paramount to reduce the risk of ischemic complications such as visual loss and strokes, vascular stenosis and occlusion, and aortic aneurysm formation. Use of imaging modalities [ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT) and [18F]-fuorodeoxyglucose positron emission tomography (PET)] has steadily increased to enable assessment of cranial and extracranial arteries, as well as the aorta. These imaging modalities are less invasive, more sensitive and readily available compared to temporal artery biopsy (TAB).”
    EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice summary.  
    Bardi M, Diamantopoulos AP.  
    Radiol Med. 2019 Oct;124(10):965-972. 
  • “Microaneurysms involving medium-sized or small arteries that are often found together with stenotic/occlusive lesions are the hallmark of PAN. Microaneurysms are most frequently identified at renal and splanchnic artery branches (particularly hepatic artery and mesenteric artery). Nonetheless, they are commonly present also in skeletal muscle arteries. Typically, they are saccular or fusiform, and 1–5 mm in diameter.”
    Clinical Approach to Diagnosis and Therapy of Polyarteritis Nodosa.  
    Hočevar A et al.
    Curr Rheumatol Rep. 2021 Feb 10;23(3):14.
  • “PAN is a systemic necrotizing vasculitis that typically affects medium-sized muscular arteries. The diagnosis of this rare disease is primarily based on clinical findings, imaging, and histopathological findings. Different PAN variants have been recognized, and they differ in their etiology as well as in the level of severity and prognosis. Cutaneous PAN usually has a favorable prognosis and requires a less aggressive therapeutic approach, based on nonsteroidal anti-inflammatory drugs to glucocorticoids; the focus of HBV-associated PAN is to control of the viral infection and remove immune complexes. TNF alpha inhibitors are the drugs of choice for PAN associated with ADA2 deficiency. Treatment of idiopathic generalized PAN is guided by disease severity and is in severe cases based on the combination of glucocorticoids and cyclophosphamide. Anti-TNF agents, tocilizumab, or rituximab may be a treatment option in refractory PAN.”
    Clinical Approach to Diagnosis and Therapy of Polyarteritis Nodosa.  
    Hočevar A et al.
    Curr Rheumatol Rep. 2021 Feb 10;23(3):14.
  • "The stenosis/occlusion and the rupture of inflamed visceral arteries, with subsequent tissue/organ ischemia, damage, dysfunction, and/or bleeding, are the causes of the most profound PAN manifestations. Almost any organ/organ system can be affected by PAN, though pulmonary involvement is uncommon. The most frequently involved organs are the peripheral nervous system and the skin. Cutaneous features include livedo reticularis, subcutaneous nodules, skin infarcts and ulcers, as well as purpura. Mononeuritis multiplex is the most common neurologic manifestation, followed by symmetric polyneuropathy. The involvement of the central nervous system is rare in idiopathic systemic PAN. Gastrointestinal tract inflammation and ischemia often presenting as acute surgical abdomen is one of the most serious PAN manifestations, occurring in up to one-third of cases.”
    Clinical Approach to Diagnosis and Therapy of Polyarteritis Nodosa.  
    Hočevar A et al.
    Curr Rheumatol Rep. 2021 Feb 10;23(3):14.
  • “Kidneys are commonly affected, with vasculitis of the renal and interlobar arteries, less frequently of the smaller arcuate and interlobular arteries leading to tissue infarctions and microaneurysm rupture. Patients develop micro- or macro-hematuria, and often mild to moderate proteinuria. New onset hypertension is secondary to intrarenal artery involvement and occurs in up to 35% of PAN patients. Renal infarctions or uncontrolled hypertension may lead to chronic renal failure.”
    Clinical Approach to Diagnosis and Therapy of Polyarteritis Nodosa.  
    Hočevar A et al.
    Curr Rheumatol Rep. 2021 Feb 10;23(3):14.
  • Large Vessel Vasculitis: Takayasu Arteritis
    Takayasu arteritis, which is also known as “aortic arch syndrome” and “pulseless disease”, is an idiopathic inflammatory disease that primarily affects large vessels such as the aorta, major branches of the aorta, and coronary and pulmonary arteries. Pathologically, TA is characterized by panarteritis affecting all three arterial layers, and subsequent scarring of media leading to luminal occlusion
  • Large Vessel Vasculitis: Takayasu Arteritis
    Takayasu arteritis occurs worldwide, but is much more common in Asia. Women are predominantly affected compared to men, with a 7:1 ratio . The American College of Rheumatology states that TA can be suspected when patients have at least three of the following criteria; age < 40 years at disease onset, claudication of the extremities, decreased brachial artery pressure, blood pressure difference of more than 10 mm Hg in between the arms, bruit over the subclavian arteries or aorta, and abnormal arteriographic results.
  • Takayasu Arteritis: Facts
    - Aortic involvement is common in TA; thoracic aorta and its branches are commonly affected, with a 65% prevalence 
    - Pulmonary arteries and coronary arteries could also be affected, with prevalences of 63.3 and 44.4%, respectively
    - In the late phase (occlusive stage), arterial stenosis, occlusion, or aneurysmal dilatation may occur, associated with the mural thickening
  • Large Vessel Vasculitis:  Giant Cell Arteritis
    - Giant cell arteritis (GCA) is another form of large vessel vasculitis affecting the aorta and its large arterial branches. Characteristically, it commonly affects the branches of carotid arteries, vertebral arteries, and temporal arteries, leading to characteristic temporal headaches
    - GCA predominantly affects female patients who are older than 50 years old, and is prevalent in the western countries, in contrast to TA.
  • Medium Vessel Vasculitis: Polyarteritis Nodosa
    - Polyarteritis nodosa (PAN) is a necrotizing vasculitis of medium and small arteries without glomerulonephritis, and is unassociated with the anti-neutrophil cytoplasmic antibody (ANCA) 
    - Polyarteritis nodosa affects men twice as often as women in the 5–7th decades. Etiology is unclear, but the hepatitis B virus may play an important role in the development of the disease. Renal involvement is common with an incidence of 70–80%, resulting in proteinuria, hematuria, and hypertension, but not glomerulonephritis.
  • Medium Vessel Disease: Kawasaki Disease
    - Kawasaki disease is a medium vessel vasculitis associated with mucocutaneous lymph node syndrome, and it frequently occurs in infants and children younger than 5 years. Although exact pathogenesis is unknown, it seems likely that infection or autoimmunity play a critical role.
    - Coronary artery involvement is common in patients with KD, therefore myocardial ischemia or infarction frequently occur. CT findings include coronary artery aneurysm, ectasia, premature atherosclerosis and stenosis. A typical braid-like appearance of coronary arteries is one of the characteristics of KD 
  • Small Vessel Vasculitis
    Small vessel vasculitides mainly affect small intraparenchymal arteries, arterioles, capillaries, and venules. They are divided into two categories; ANCA-associated small vessel vasculitis and immune complex-associated small vessel vasculitis.
  • Mimickers of Vasculitis
    - Fibromuscular dysplasia (FMD)
    - Segmental arterial mediolysis
    - Neurofibromatosis type 1
  • Coronary Artery Aneurysms: Causes
    - Atherosclerotic disease
    - Vasculitis (Kawasaki Disease, Takayasu Disease, PAN)
    - Connective Tissue Disease (Marfans, Ehlers-Danlos disease)
    - Infection (Bacterial, mycobacterial, fungal, Lyme disease)
    - IVDA (cocaine, amphetamines)
    - Congenital (FMD)
  • Kawasaki Disease: Facts
    - Occurs in children younger than 5 yrs with peak under age 2 yrs
    - Male > female by 1.5x
    - More common in Asians especially Japanese
    - Acute febrile systemic illness in children
    - AKA mucocutaneous lymph node syndrome
  • Kawasaki Disease: Facts
    - Fever for 5 days or more without a cause and four of the following
    --- Bilateral conjunctival injection
    --- Mucous membrane changes (strawberry tongue)
    --- Extremity abnormalities including erythema of palms or soles, edema of hands or feet
    --- Rash
    --- Cervical lymphadenopathy
  • Kawasaki Disease: Facts
    - Cardiac abnormalities
    --- Pericardial effusion (30%)
    --- Myocarditis
    --- Mitral regurgitation (30%)
    --- Aortitis and aortic regurgitation
    --- Congestive heart failure
    --- Coronary artery aneurysms
  • Kawasaki Disease: Facts
    - Coronary artery aneurysms occur in up to 25% of patients treated with aspirin alone or no treatment
    - Aneurysms develop within 2 weeks (1-4 weeks) with a 2% mortality rate
    - Aneurysms are more common in the proximal than distal coronary artery
    - Aneurysms may thrombosis which results in sudden death
    - Vascular complication rate decreased with proper therapy (aspirin and intravenous immune globulin) to around 5% for aneurysms
© 1999-2021 Elliot K. Fishman, MD, FACR. All rights reserved.