Heterotopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separate from the main gland. The most common locations of this displacement include the upper gastrointestinal ...tract-specifically, the stomach, duodenum, and proximal jejunum. Less common sites are the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Uncomplicated heterotopic pancreas is typically asymptomatic, with the lesion being discovered incidentally during an unrelated surgery, during an imaging examination, or at autopsy. The most common computed tomographic appearance of heterotopic pancreas is that of a small oval intramural mass with microlobulated margins and an endoluminal growth pattern. The attenuation and enhancement characteristics of these lesions parallel their histologic composition. Acinus-dominant lesions demonstrate avid homogeneous enhancement after intravenous contrast material administration, whereas duct-dominant lesions are hypovascular and heterogeneous. At magnetic resonance imaging, the heterotopic pancreas is isointense to the orthotopic pancreas, with characteristic T1 hyperintensity and early avid enhancement after intravenous gadolinium-based contrast material administration. Heterotopic pancreatic tissue has a rudimentary ductal system in which an orifice is sometimes visible at imaging as a central umbilication of the lesion. Complications of heterotopic pancreas include pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception. Certain complications may be erroneously diagnosed as malignancy. Paraduodenal pancreatitis is thought to be due to cystic degeneration of heterotopic pancreatic tissue in the medial wall of the duodenum. Recognizing the characteristic imaging features of heterotopic pancreas aids in differentiating it from cancer and thus in avoiding unnecessary surgery.
RSNA, 2017.
The Liver Imaging Reporting and Data System (LI-RADS) is a reporting system created for the standardized interpretation of liver imaging findings in patients who are at risk for hepatocellular ...carcinoma (HCC). This system was developed with the cooperative and ongoing efforts of an American College of Radiology-supported committee of diagnostic radiologists with expertise in liver imaging and valuable input from hepatobiliary surgeons, hepatologists, hepatopathologists, and interventional radiologists. In this article, the 2017 version of LI-RADS for computed tomography and magnetic resonance imaging is reviewed. Specific topics include the appropriate population for application of LI-RADS; technical recommendations for image optimization, including definitions of dynamic enhancement phases; diagnostic and treatment response categories; definitions of major and ancillary imaging features; criteria for distinguishing definite HCC from a malignancy that might be non-HCC; management options following LI-RADS categorization; and reporting.
RSNA, 2017.
The Liver Imaging Reporting and Data System (LI-RADS) is composed of four individual algorithms intended to standardize the lexicon, as well as reporting and care, in patients with or at risk for ...hepatocellular carcinoma in the context of surveillance with US; diagnosis with CT, MRI, or contrast material-enhanced US; and assessment of treatment response with CT or MRI. This report provides a broad overview of LI-RADS, including its historic development, relationship to other imaging guidelines, composition, aims, and future directions. In addition, readers will understand the motivation for and key components of the 2018 update.
Angiosarcoma is a rare, aggressive subtype of soft-tissue sarcoma with a propensity for local recurrence and metastasis associated with a generally poor prognosis, unless diagnosed early. Given the ...vascular endothelial cell origin of angiosarcoma, tumours may develop in essentially any organ; however, there is a predilection for the skin where half of all tumours arise, increasing in prevalence with age. The most common risk factors are chronic lymphoedema and history of radiation. We review the most important radiological findings along the spectrum of angiosarcoma from head to toe throughout the body, including uncommon and rare locations. Key imaging features of angiosarcoma across multiple organ systems will be described, as well as the impact on management and prognosis.
Fibrolamellar hepatocellular carcinoma (HCC) is a rare primary liver tumor, which significantly differs from conventional HCC. This article reviews the molecular cytogenetics, pathology, imaging ...features, and management of this relatively rare tumor.
Fibrolamellar HCC predominantly occurs in young patients without underlying hepatitis or cirrhosis. Serum α-fetoproteins are not elevated in most cases, and hence imaging plays an important role in diagnosis, staging, and surveillance.
Inflammatory pseudotumor: the great mimicker Patnana, Madhavi; Sevrukov, Alexander B; Elsayes, Khaled M ...
American journal of roentgenology (1976)
198, Številka:
3
Journal Article
Recenzirano
The purpose of this review is to describe the pathophysiologic findings, differential diagnosis, imaging features, and management of inflammatory pseudotumor in various locations throughout the body.
...Inflammatory pseudotumor is a rare benign process mimicking malignant processes and has been found in almost every organ system. Radiologists should be familiar with this entity as a diagnostic consideration to avoid unnecessary surgery.
The incidence of hematologic malignancies and their extranodal manifestations is continuously increasing. Previously unsuspected hepatic involvement in hematologic malignancies such as Hodgkin ...disease and non-Hodgkin lymphoma, posttransplant lymphoproliferative disorder, myeloid sarcoma (chloroma), multiple myeloma, Castleman disease, and lymphohistiocytosis may be seen by radiologists. Although the imaging features of more common hepatic diseases such as hepatocellular carcinoma, metastases, and infection may overlap with those of hepatic hematologic malignancies, combining the imaging features with clinical manifestations and laboratory findings can facilitate correct diagnosis. Clinical features that suggest a hematologic neoplasm as the cause of liver lesions include a young patient (<40 years of age), no known history of cancer, abnormal bone marrow biopsy results, fever of unknown origin, and night sweats. Imaging features that suggest hematologic malignancy include hepatosplenomegaly or splenic lesions, vascular encasement by a tumor without occlusion or thrombosis, an infiltrating mass at the hepatic hilum with no biliary obstruction, and widespread adenopathy above and below the diaphragm. Familiarity with the imaging features of hepatic hematologic malignancies permits correct provisional diagnosis and may influence therapeutic management. For example, when biopsy is performed, core biopsy may be needed in addition to fine-needle aspiration so that the tissue architecture of the neoplasm can be discerned. The predominant treatment of hematologic malignancies is chemotherapy or radiation therapy rather than surgery. Online supplemental material is available for this article.
Objective
To evaluate the imaging features of hepatic epithelioid hemangioendothelioma (HEH) on multiphasic CT, MR, and FDG-PET-CT.
Methods
Bi-institutional review identified 67 adults (mean age, ...47 years; 23 M/44 F) with pathologically proven HEH and pretreatment multiphasic CT (
n
= 67) and/or MR (
n
= 30) and/or FDG-PET-CT (
n
= 13).
Results
HEHs were multifocal in 88% (59/67). Mean size of the dominant mass was 4.1 cm (range, 1.4–19 cm). The tumors were located in the peripheral, subcapsular regions of the liver in 96% (64/67). Capsular retraction was present in 81% (54/67 cases) and tumors were coalescent in 61% (41/67). HEH demonstrated peripheral ring enhancement on arterial phase imaging in 33% (21/64) and target appearance on the portal venous phase in 69% (46/67). Persistent peripheral enhancement on the delayed phase was seen in 49% (31/63). On MR, multilayered target appearance was seen on the T2-weighted sequences in 67% (20/30) and on the diffusion-weighted sequences in 61% (11/18). Target appearance on hepatobiliary phase of MRI was seen in 57% (4/7). On pre-therapy FDG-PET-CT, increased FDG uptake above the background liver parenchyma was seen in 62% (8/13).
Conclusion
HEHs typically manifest as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction. Peripheral arterial ring enhancement and target appearance on portal venous phase are commonly seen on CT. Similarly, multilayered target appearance correlating with its histopathological composition is typically seen on multiple sequences of MR including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced multiphasic MR.
Key Points
• Hepatic epithelioid hemangioendotheliomas manifest on CT and MR as multifocal, coalescent hepatic nodules in peripheral subcapsular location, with associated capsular retraction.
• Enhancement pattern on contrast-enhanced CT and MR can vary but peripheral ring enhancement on arterial phase and target appearance on portal venous phase are commonly seen.
• Retrospective two-center study showed that cross-sectional imaging may help in the diagnosis.
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