Neurosarcoidosis: radiologic features in five patients.

This paper describes the radiological features in five biopsy-confirmed cases of neurosarcoidosis. The imaging appearance of neurosarcoidosis is highly variable, making the diagnosis difficult on the basis of intracranial images alone. However, if there is evidence of spread along the pia mater, and meningeal mass formation with a lower intensity in the central area and higher intensity in the peripheral area on T2-weighted and FLAIR images, neurosarcoidosis can be considered.

Lymphoepithelial cyst of the pancreas: case report with special reference to imaging--pathologic correlation.

We report a case of resected lymphoepithelial cyst of the pancreas with special reference to the imaging-pathologic correlation. Visualization of a multilocular cystic nature with internal heterogeneous hyperechogenicity on ultrasound, hyperdensity on precontrast computed tomography, and granular hypointensity on T2-weighted image due to abundant internal keratin substances were considered to be keys to the differential diagnosis from other cystic lesions of the pancreas.

Intraluminal duodenal diverticulum: MR findings.

We report a case of intraluminal duodenal diverticulum with special reference to its magnetic resonance imaging findings. An intraluminal duodenal fluid collection surrounded by a hypointense rim on T2-weighted or magnetic resonance cholangiopancreatographic images, the shape of which is changed by peristalsis, is considered to be almost diagnostic for intraluminal duodenal diverticulum.

Solid serous cystadenoma of the pancreas: MR imaging with pathologic correlation.

We report a case of solid type serous cystadenoma of the pancreas. Computed tomographic and magnetic resonance (MR) images showed a hypervascular solid tumor that was difficult to differentiate from endocrine tumor of the pancreas. However, the tumor showed marked hyperintensity similar to that of hepatic cyst on MR cholangiopancreatography, indicating not a solid but rather a cystic nature. MR cholangiopancreatography (heavily T2-weighted image) is quite useful for clearly differentiating solid from cystic tumors.

MRI findings of primary biliary cirrhosis: correlation with Scheuer histologic staging.

Magnetic resonance imaging (MRI) findings of primary biliary cirrhosis (PBC; currently regarded as a vanishing bile duct syndrome) are not established. In this report, we describe our preliminary analysis of the relation between MRI findings and histopathologic staging of PBC and review clinical, morphologic, and MRI findings of PBC especially focusing on the staging of PBC.

Focal sparing of fatty liver in segment II associated with aberrant left gastric vein.

We present a patient with aberrant left gastric vein (LGV) that directly enters the posterior edge of segment II in the liver. The corresponding area was focally spared of fatty liver. We consider that this aberrant LGV contributed to the cause of focal sparing. This is the first report of the use of helical CT and Doppler ultrasound to depict the aberrant LGV that directly enters the liver.

Tumor-associated focal chronic pancreatitis from invasion of the pancreatic duct by common bile duct carcinoma: radiologic-pathologic correlation.

We report a case of tumor-associated focal chronic pancreatitis of the uncinate process of the pancreas. The chronic pancreatitis was secondary to stenosis of the main pancreatic duct from invasion by a common bile duct carcinoma. A feature distinguishing the chronic pancreatitis from pancreatic carcinoma was the localized dilatation of pancreatic duct branches evident in the focal lesion of the uncinate process.

Cystic duct remnant carcinoma with widespread invasion along the extrahepatic bile duct wall: dynamic CT findings.

We report a case of remnant cystic duct carcinoma with widespread invasion along the common bile duct wall. Thin-slice dynamic computed tomography showed circumferential wall thickening of the extrahepatic bile duct (from the common hepatic duct to the intrapancreatic common bile duct) and the remnant cystic duct. Pathologically, the extrahepatic bile duct wall was thickened due to submucosal tumor infiltration by cystic duct papillary adenocarcinoma.

Peritumoral spared area in fatty liver: correlation between opposed-phase gradient-echo MR imaging and CT arteriography.

BACKGROUND: The purpose of the present study was to evaluate the magnetic resonance findings of a spared area of fatty liver caused by hepatic tumors and clarify the etiology of this phenomenon by computed tomographic (CT) arteriography. METHODS: Six patients with hepatic tumors (metastases from colon cancer, n = 3; breast cancer, n = 2; hepatocellular carcinoma, n = 1) were examined. In-phase (IP) and opposed-phase (OP) T1-weighted spoiled gradient-echo images were obtained. CT during arterial portography (CTAP) and CT during hepatic arteriography (CTHA) were also performed. Pathologic confirmation was obtained in three patients with metastases from colon cancer. RESULTS: In all six patients, peritumoral ringlike or wedge-shaped hyperintense areas in relation to the tumor and the surrounding steatotic liver parenchyma were clearly visualized on OP images alone. This area appeared as a perfusion defect on CTAP and ringlike or wedge-shaped enhancement on CTHA. Pathologically, the peritumoral hyperintense areas on OP images were compatible with the spared area of fatty liver. CONCLUSION: A peritumoral spared area can be demonstrated with OP images. The etiology of the phenomenon is correlated with decreased portal flow and increased arterial flow in the peritumoral hepatic parenchyma.

Pseudolesion in segment IV of the liver adjacent to the falciform ligament caused by drainage of the paraumbilical vein: demonstration by power Doppler ultrasound.

A case of a pseudolesion in segment IV of the liver, adjacent to the falciform ligament, was observed on conventional CT and CT during arterial portography. The pseudolesion was caused by drainage of the paraumbilical vein. Power Doppler ultrasound was helpful in recognizing this pseudolesion by depicting that the paraumbilical vein was connected to vessels in this area. Although the direction of flow could not be determined, power Doppler ultrasound is a useful method for confirming non-invasively the aetiology of pseudolesions in this area.

CT arteriographic confirmation of focal hepatic fatty infiltration adjacent to the falciform ligament associated with drainage of inferior vein of Sappey: a case report.

We experienced a case of focal fatty infiltration in the anteromedial edge of the medial segment of the liver adjacent to the falciform ligament associated with advanced esophageal cancer. By using CT during selective right internal thoracic arteriography, we confirmed that the inferior vein of Sappey drained into the area of focal fatty infiltration. This is the first case to directly establish the relationship between drainage of the inferior vein of Sappey and occurrence of focal fatty infiltration of the liver.

Dynamic CT of hepatic abscesses: significance of transient segmental enhancement.

OBJECTIVE: The purpose of this study was to evaluate dynamic CT findings of hepatic abscesses, especially segmental hepatic enhancement, and to clarify the cause. MATERIALS AND METHODS: Twenty-four abscesses in eight patients were examined by early (30 sec) and late phase (90 sec) dynamic CT. Patients underwent abscess drainage (n = 1), hepatic resection (n = 2), or antibiotic therapy (n = 5). CT during arterial portography and CT during hepatic arteriography were performed in one patient. We retrospectively observed the frequency and changes of segmental hepatic enhancement on dynamic CT and determined its cause using radiologic and pathologic correlation. RESULTS: Sixteen abscesses (67%) showed transient segmental hepatic enhancement and three abscesses showed only segmental hepatic enhancement in the early phase. Four abscesses in one patient who underwent CT during arterial portography and CT during hepatic arteriography showed a segmental perfusion defect on CT during arterial portography and segmental enhancement on CT during hepatic arteriography. On follow-up dynamic CT performed 10-17 days after the initial CT, segmental hepatic enhancement surrounding hepatic abscesses decreased or disappeared in all abscesses. Pathologic examination of two patients showed marked inflammatory cell infiltration with stenosis of portal venules within the portal tracts surrounding hepatic abscesses without definite inflammation in the liver parenchyma. CONCLUSION: Segmental hepatic enhancement on dynamic CT is frequently associated with hepatic abscesses and may be caused by decreased portal flow resulting from inflammation of the portal tracts.

Accumulation of iodized oil within the nonneoplastic liver adjacent to hepatocellular carcinoma via the drainage routes of the tumor after transcatheter arterial embolization.

PURPOSE: After transcatheter arterial embolization (TAE) with iodized oil (Lipiodol), a relatively dense accumulation of Lipiodol is often seen in the nontumorous liver adjacent to a hypervascular hepatocellular carcinoma (HCC) nodule. We compared this phenomenon with the findings obtained with single-level dynamic CT during hepatic arteriography (SLDCTHA) and presumed its possible mechanism. METHODS: Fifty-six patients with HCC underwent hepatic angiography including SLDCTHA followed by segmental or subsegmental TAE with a mixture of an anticancer drug and Lipiodol. We compared the drainage area of the HCC depicted on SLDCTHA with the Lipiodol accumulation in the nontumorous liver adjacent to the HCC on CT after TAE (LpCT). RESULTS: In 26 of the 56 patients, a definite corona enhancement around the HCC, suggesting the drainage of blood from the tumor into the surrounding liver parenchyma, was seen on the late phase of SLDCTHA. In 17 of these 26 patients (65.4%), LpCT showed a more intense accumulation of Lipiodol in the nontumorous liver adjacent to the HCC that corresponded to the drainage area revealed on SLDCTHA. CONCLUSION: The drainage of blood from the HCC was considered to be a possible mechanism of the accumulation of Lipiodol in the nontumorous liver adjacent to the HCC.

MR imaging of focal splenic extramedullary hematopoiesis in polycythemia vera: case report.

We report a case with focal mass-like lesion of the spleen in polycythemia vera. Magnetic resonance imaging of the lesion showed homogeneous hyperintensity on T2-weighted images, with progressive enhancement on dynamic magnetic resonance images after bolus injection of gadolinium. The magnetic resonance features of focal splenic extramedullary hematopoiesis have not been previously reported.

Intrahepatic biliary calculi: correlation of unusual MR findings with pathologic findings.

We report a case of intrahepatic biliary calculi. A localized dilated intrahepatic duct of the left lateral segment of the liver was filled with material that showed marked hyperintensity on T1- and T2-weighted magnetic resonance (MR) images. These MR findings are unusual for intrahepatic stones. Pathologically, the stones were muddy bilirubin calculi, the chemical and physical characteristics of which are surmised to have been the cause of the unusual MR findings.

Enlargement of hilar periportal space: a sign of early cirrhosis at MR imaging.

The purpose of this study was to determine whether the finding of an enlarged hilar periportal space is a sign for early cirrhosis at magnetic resonance (MR) imaging. Forty-one pathologically proved cirrhotic patients in the early stage of disease who did not show conventional imaging findings of cirrhosis (early cirrhosis group) and 47 patients without history of chronic liver diseases (control group) were included in this study. MR images were qualitatively and quantitatively evaluated for the presence of enlargement of the periportal space. Enlargement of the periportal space was seen in 98% of patients in the early cirrhosis group, while this finding was seen in 11% of patients in the control group (P < 0.0001). The mean value of the hilar periportal fat thickness was significantly greater (P < 0.0001) in the early cirrhosis group (15.5 +/- 6.2 mm) than in the control group (5.3 +/- 3.1 mm). The sensitivity, specificity, accuracy, and positive predictive value of this finding for the MR diagnosis of cirrhosis with a cutoff value of 10 mm were 93%, 92%, 92%, and 91%, respectively. Enlargement of the hilar periportal space is a helpful sign at MR imaging in the discrimination between normal and early cirrhotic livers.

Free MRA of the abdomen: postprocessing dynamic gadolinium-enhanced 3D axial MR images.

Dynamic contrast-enhanced whole-abdomen axial images were obtained by using a fat-suppressed, three-dimensional, breath-hold enhanced fast spoiled gradient-echo technique, configured for optimal evaluation for detection and characterization of liver lesions. We then evaluated the feasibility of using these images to reconstruct "free" abdominal magnetic resonance angiography, without additional cost or acquisition time, in 32 randomly chosen patients. The aorta, celiac trunk, superior mesenteric, hepatic, splenic, and renal arteries were clearly depicted.

Correlation between the blood supply and grade of malignancy of hepatocellular nodules associated with liver cirrhosis: evaluation by CT during intraarterial injection of contrast medium.

OBJECTIVE: The purpose of this study is to evaluate the correlation between the intranodular blood supply revealed by CT during intraarterial injection of contrast medium, mainly using helical CT, and the grade of malignancy of hepatocellular nodules associated with liver cirrhosis as classified by the International Working Party of the World Congress of Gastroenterology. SUBJECTS AND METHODS: We studied 201 histologically proven nodules (101 resected and 100 biopsied nodules), including 47 low-grade dysplastic nodules (low-DNs), 56 high-grade dysplastic nodules (high-DNs), 24 well-differentiated hepatocellular carcinomas (wd-HCCs), and 74 moderately or poorly differentiated HCCs (mp-HCCs), in 139 cirrhotic patients. Findings on CT during arterial portography (n = 201) and CT during hepatic arteriography (n = 74) were reviewed and compared with the histologic diagnosis. RESULTS: CT findings were classified into four types relative to the surrounding liver: type A (isodense), type B (slightly hypodense), type C (partially hypodense), and type D (markedly hypodense) on CT during arterial portography and type I (isodense), type II (hypodense), type III (partially hyperdense), and type IV (hyperdense) on CT during hepatic arteriography. On CT during arterial portography, the distributions of each type were low-DN (n = 47 [A, n = 36; B, n = 8; C, n = 3]), high-DN (n = 56 [A, n = 18; B, n = 20; C, n = 10; D, n = 8]), wd-HCC (n = 24; [B, n = 4; C, n = 13; D, n = 7]), and mp-HCC (n = 74 [D, n = 74]). On CT during hepatic arteriography, the distributions were low-DN (n = 26 [I, n = 18; II, n = 7; III, n = 1]), high-DN (n = 19 [I, n = 6; II, n = 7; III, n = 4; IV, n = 2]), wd-HCC (n = 15 [I, n = 1; III, n = 8; IV, n = 6]), and mp-HCC (n = 14 [IV, n = 14]). We found a statistically significant correlation between the four types and the grade of malignancy of these nodules. CONCLUSION: Findings on CT during arterial portography and CT during hepatic arteriography correlated positively with histologic grading when overlap in appearance between dysplastic nodules and HCCs occurred. The concept revealed in this study can apply to diagnoses made on the basis of Doppler sonography, dynamic CT, and MR imaging.