Portal vein occlusion or stenosis in patients with hepatolithiasis: observation by multiphasic contrast-enhanced CT.

AIMS: To analyze the dynamic findings of multiphasic contrast-enhanced CT in hepatolithiasis and to elucidate occlusive changes in portal veins and other associated abnormalities. METHODS: This was a retrospective study of 25 selected patients with hepatolithiasis who underwent various imaging examinations, including multiphasic contrast-enhanced CT. The following CT findings were evaluated in each of 71 hepatic segments: visualization of a calculus; biliary dilation or focal hepatic atrophy of the affected segment; areas that were abnormally enhanced in the hepatic arterial phase; degrees (normal, stenosis, occlusion) of portal vein calibre; and linear delayed enhancement along the bile-duct walls, suggesting cholangitis. RESULTS: On CT, calculi were depicted as a hyperdense structures in 61 of 71 segments (86%). Focal hepatic atrophy, which frequently accompanied CT findings suggesting compensatory hypertrophy of other segments, was seen in 50 of 71 segments (70%). Areas that were abnormally enhanced were recognized in 36 of 71 segments (51%). Stenosis or occlusion of portal venous branches was observed in 59 of 71 segments (83%), including 13 segments with occlusion. Findings indicating cholangitis were noted in 50 of 71 segments (70%). The degrees of portal vein calibre were significantly correlated with the presence of hepatic atrophy or cholangitis. CONCLUSION: Hepatolithiasis is associated with significant rates of stenosis or occlusion of adjacent portal veins as well as hepatic parenchymal changes in the affected area. Chronic deterioration of portal flow may cause these morphological changes.

Bilateral ovarian leiomyomas: CT and MRI features.

We recently treated a 21-year-old woman with leiomyomas arising from the bilateral ovaries, a very rare condition. On magnetic resonance imaging, more than half of the left adnexal mass showed low signal intensity on T2-weighted images and good enhancement by gadolinium-DTPA, and the remaining part showed high signal intensity on T2-weighted images, so the lesions initially were diagnosed as ovarian fibromas or as thecomas with a certain degree of degeneration. Pathologic examination of the excised tumors proved that they were bilateral ovarian leiomyomas; in addition, the tumor from the left side showed hemorrhagic and myxoid changes with torsion of 180 degrees.

Liver lesions of visceral larva migrans due to Ascaris suum infection: CT findings.

The purpose of this study was to analyze computed tomographic (CT) findings of hepatic lesions due to Ascaris suum infection. CT of the liver in three patients, all of whom had immunoserologically confirmed A. suum infection, were retrospectively reviewed. Twenty-five lesions were identified in total. Two radiologists analyzed CT findings in a consensus fashion, with particular interest in the margin, shape, and location of the lesions. Hepatic lesions were ill-defined (22 of 25), small (3-35 mm; average, 11 mm), and nodular (18 of 25) or wedge (three of 25) in shape. Most were located in periportal (16 of 25) or subcapsular (six of 25) regions. Hepatic nodules due to visceral larva migrans of A. suum were located mainly in periportal or subcapsular regions, which may represent periportal eosinophilic granuloma, its pathologic feature. The results were considered to represent the pathophysiology of this entity.

Fat in liver metastasis from renal cell carcinoma detected by chemical shift MR imaging.

A case with liver metastasis from papillary renal cell carcinoma (RCC) is presented, in which intratumoral fat was detected on dual-echo chemical shift magnetic resonance imaging (MRI). The preoperative chemical shift MR image of the primary RCC also suggested the presence of intratumoral fat. Liver metastasis from fat-containing RCC should be included in the differential diagnosis of fat-containing liver masses as observed on chemical shift MRI.

Fat detection in gallbladder carcinoma with extensive xanthogranulomatous change demonstrated by chemical shift MR imaging.

We present a case of gallbladder carcinoma, in which fat was detected on dual-echo chemical shift magnetic resonance imaging (MRI). Histologic analysis showed poorly differentiated adenocarcinoma associated with massive xanthogranulomatous change. Sudan IV staining successfully confirmed the presence of fat within the interstitial histiocytes. Although rare, gallbladder carcinoma with xanthogranulomatous change should be included in the differential diagnosis of fatty tumor involving the region of the liver as observed on chemical shift MRI.

Gallbladder torsion: case report.

Torsion of the gallbladder (GB) is a rare, acute abdominal condition. The treatment of choice is cholecystectomy. Even with recent advances in radiologic imaging modalities, it is difficult to make a correct preoperative diagnosis of GB torsion. We report a case of GB torsion with a retrospective review of the radiologic findings of magnetic resonance imaging, computed tomography, and ultrasonography. Those findings were compared with the histopathologic findings of the surgical specimen. The radiologic findings in our case were useful for making a preoperative diagnosis of GB torsion. We postulate the characteristic magnetic resonance findings and discuss discrepancies in the evaluations of the GB wall.

Measurement of the apparent diffusion coefficient in intraductal mucin-producing tumor of the pancreas by diffusion-weighted echo-planar MR imaging.

BACKGROUND: We investigated whether diffusion-weighted echo-planar magnetic resonance (MR) imaging can help differentiate intraductal mucin-producing tumors of the pancreas from other cystic lesions. METHODS: Diffusion-weighted echo-planar MR imaging was performed in patients with mucin-producing tumors (n = 19), pseudocysts (n = 9), chronic pancreatitis with diffuse main pancreatic dilatation (n = 5), and serous cystadenomas (n = 2). Images were obtained with diffusion sensitizing gradients of 30, 300, and 900 s/mm2. The apparent diffusion coefficient (ADC) was calculated. RESULTS: The mean (+/- standard deviation) ADCs of mucin-producing tumors (2.8 x 10(-3) mm2/s +/- 1.0 x 10(-3)), pseudocysts (2.9 x 10(-3) mm2/s +/- 1.2 x 10(-3)), dilated main pancreatic duct in chronic pancreatitis (3.3 x 10(-3) mm2/s +/- 1.2 x 10(-3)), serous cystadenomas (2.9 x 10(-3) and 2.6 x 10(-3) mm2/s), and cerebrospinal fluid (3.5 x 10A(-3) mm2/s +/- 1.1 x 10(-3)) were not statistically different. CONCLUSION: It is difficult to differentiate between mucin-producing tumors and other cystic lesions by ADC measurements when using diffusion-weighted echo-planar MR imaging.

[A safe and simple method of percutaneous transfemoral implantation of a port-catheter access system for hepatic artery chemotherapy infusion].

The purpose of this study was to perform a simple percutaneous transfemoral implantation of a portcatheter access system using a new catheter coating for hepatic artery chemotherapy infusion, and to evaluate the complications of transfemoral infusion port implantation. The methods of treatment for complications were also studied. The port-catheter system was percutaneously implanted via femoral artery access in 180 patients with malignant liver tumors. Blood flow redistribution was performed using embolization coils. An unfixed 5 Fr catheter was placed in a hepatic artery, and connected to a port implanted subcutaneously below the level of the inguinal ligament. The success rate of implantation was 99%. Complications after placement were observed as follows: port system obstruction (9.6%); dislocation of the catheter tip (8.4%); drug toxicity (4.5%); and infection (3.4%). Notable is the avoidance of cerebral infarcts. In 3 of 17 patients with port obstruction, recanalization of the port was achieved. In 11 of 15 patients with catheter dislocation, replacement of the catheter-port system was successful. In 5 patients with hepatic artery occlusion, the replacement of a microcatheter-port access system was achieved, and hepatic artery chemotherapy infusion was resumed. This percutaneous transfemoral implantation of a catheter-port access system would seem to be a very simple and useful method for many clinical doctors, and it may improve the quality of life in patients with an unresectable malignant liver tumor.

Radiologic diagnosis of adenomyomatosis of the gallbladder: comparative study among MRI, helical CT, and transabdominal US.

PURPOSE: The goal of this work was to evaluate the diagnostic accuracy of transabdominal ultrasound (US), helical CT, and MRI in the diagnosis of adenomyomatosis (ADM) of the gallbladder. METHOD: Twenty patients with surgically proven ADM were included, all of whom underwent preoperative US, helical CT with 3 mm collimation, and MRI with half-Fourier rapid acquisition with relaxation enhancement (RARE). All images were retrospectively reviewed by two radiologists, and the presence of ADM was assessed at three compartments (neck, body, and fundus) of the organ. Receiver operating characteristic analysis was performed, and sensitivity, specificity, and accuracy were calculated for each modality. RESULTS: The A z values (area under the curve) for MRI, helical CT, and US were 0.98, 0.85, and 0.72 for the Reader 1, respectively, showing no statistically significant interobserver difference in any of the three modalities. MRI showed a significantly higher A z value than helical CT or US (p < 0.1). The accuracies of MRI, helical CT, and US were 93, 75, and 66%, respectively. CONCLUSION: Among the three modalities tested, MRI with half-Fourier RARE sequence was the most accurate for diagnosing ADM.

Unusual hemodynamics and pseudolesions of the noncirrhotic liver at CT.

Recognition of pseudolesions of the liver at computed tomography (CT) is important because of their close resemblance to primary liver cancers or metastases. Two types of pseudolesion in the noncirrhotic liver include that due to transient extrinsic compression, typically caused by ribs or the diaphragm, and that due to a "third inflow" of blood from other than the usual hepatic arterial and portal venous sources: the cholecystic, parabiliary, or epigastric-paraumbilical venous system. Although the location of both types of pseudolesion are characteristic, their appearances at CT during arterial portography and CT during selective angiography vary from nonenhanced low-attenuation areas to well-enhanced high-attenuation areas, depending on the amount and timing of the inflow and presence or absence of focal metabolic alteration of the hepatocytes. Radiologists need to understand the underlying mechanism of these pseudolesions to better recognize the wide range of their appearances at CT.

Sclerosed hemangioma of the liver.

We report the radiologic findings of sclerosed hemangioma (SH), a rare variant of hepatic hemangioma. Dynamic contrast-enhanced computed tomography showed a hypodense mass in the liver with delayed enhancement. T2-weighted magnetic resonance imaging showed the mass as hypointense in relation to cerebrospinal fluid. The final diagnosis of SH was made pathologically. Although SH is rare, understanding its radiologic appearance is important to avoid unnecessary surgery and should be included in the differential diagnoses of hepatic lesion with delayed enhancement.

Liver metastasis from gallbladder carcinoma: anatomic correlation with cholecystic venous drainage demonstrated by helical computed tomography during injection of contrast medium in the cholecystic artery.

BACKGROUND: The current study evaluated whether the sites of liver metastasis from gallbladder carcinoma are correlated with areas of cholecystic venous drainage (CVD) utilizing helical computed tomography (CT) during the injection of contrast medium into the cholecystic artery (cholecystic artery CT). METHODS: Cholecystic artery CT scans were performed in 26 patients with gallbladder carcinoma. Liver metastases were examined retrospectively in these patients on CT, and the sites of liver metastasis and CVD were compared closely. The patients were divided into concurrent (those who had metastasis at the time of cholecystic artery CT), early postoperative metastasis (those who developed metastasis within 6 months after surgery), and late postoperative metastasis (those who developed metastasis more than 6 months after surgery) groups. The frequency of metastasis related to CVD was compared between the three groups. RESULTS: A total of 32 metastases were identified in 11 patients, 21 of which were related to CVD. Six patients were included in the concurrent metastasis group; 18 of 20 tumors were found to be related closely to CVD. There were two patients in the early postoperative metastasis group; all three of the tumors detected were found to be closely related to CVD. Three patients were subclassified as being in the late postoperative metastasis group; none of the nine tumors detected appeared to be in areas associated with CVD. CONCLUSIONS: The sites of liver metastases were found to be well correlated with the areas with CVD, particularly in the concurrent and early postoperative metastasis groups. CVD may be a useful marker of potential areas of liver metastasis from gallbladder carcinoma, particularly in patients with early stage metastasis.

Complications encountered with a transfemorally placed port-catheter system for hepatic artery chemotherapy infusion.

A port-catheter system was implanted via femoral artery access for hepatic artery chemotherapy infusion. Implantation was attempted in 90 patients and was successful in 88. Blood flow redistribution was performed using embolization coils. In the first ten patients a soft heparin-coated infusion catheter was used. For the following 78 patients we used a stiffer catheter coated with fluorine-acryl-styrene-urethane-silicone (FASUS) copolymer. The catheter was connected to a port implanted subcutaneously below the level of the inguinal ligament. Complications during the procedure and after placement were observed in 7 of 90 patients and 24 of 88 patients, respectively. These included catheter obstruction (11%), dislocation of the catheter tip (10%), drug toxicity (5.7%), and catheter infection (3.4%). In 6 of 10 patients with catheter obstruction, recanalization of the port system was achieved. In 7 of 9 patients with dislocation of the indwelling catheter tip, replacement of the port system was successful. Our complications appear to be comparable with those encountered with the subclavian/brachial approach when the new catheter coating is used. Notable is the avoidance of cerebral infarcts.

Metastatic adrenal tumor from clear-cell renal cell carcinoma: a pitfall of chemical shift MR imaging.

We present a case of adrenal metastasis from clear-cell renal cell carcinoma in which presence of a small amount of fat was shown on chemical shift gradient-echo magnetic resonance imaging. Radiologists should be aware that signal loss of the adrenal tumor on out-of-phase gradient-echo images does not always suggest the diagnosis of benign adenoma, particularly in patients with a history of renal cell carcinoma.

Efficacy of three-dimensional fast imaging with steady precession dynamic MR imaging in evaluating pancreatic ductal adenocarcinoma.

To compare the diagnostic efficacy of three-dimensional fast imaging with steady precession (3D-FISP) dynamic MR imaging in assessing pancreatic ductal adenocarcinoma with conventional MR imaging and helical CT, 15 patients with surgically proven pancreatic ductal adenocarcinoma were studied. Contrast-to-noise ratio (CNR) of the tumor, tumor detectability, local tumor extension, and vascular involvement were evaluated for all techniques. The results indicate that 3D-FISP dynamic MR imaging may improve the imaging assessment of pancreatic ductal adenocarcinoma.

Spiral-shaped iatrogenic arterial dissection during superior mesenteric arteriography: a latent risk of diagnostic angiography using the power injector.

We report a rare case of iatrogenic arterial dissection of the superior mesenteric artery (SMA) during diagnostic angiography. A conventional superior mesenteric arteriogram obtained using an automated power injector revealed an arterial dissection 2s after the initiation of contrast-medium injection. This case indicates that although careful catheter manipulations during angiography are essential, certain unavoidable complications may occur.

Abdominal cystic tumors containing small amount of fat in the septa: report of two cases.

We present two cases of abdominal cystic tumors containing small amounts of fat in their septa. Although the final pathologic diagnoses of these tumors were cystic lymphangioma and angiomatosis, the computed tomographic and magnetic resonance imaging features were almost identical and indistinguishable; a purely cystic mass around the region of the pancreas head associated with little mass effect on the surrounding organs and septa containing a radiologically evident fatty component. Radiologists should be aware of these two entities as differential diagnoses of abdominal cystic masses containing small amounts of septal fat.

Pitfalls in MR cholangiopancreatographic interpretation.

Magnetic resonance (MR) cholangiopancreatography (MRCP) is widely used in the evaluation of pancreatobiliary disorders. However, numerous related pitfalls may simulate or mask pancreatobiliary disease. Maximum-intensity-projection (MIP) reconstructed images completely obscure small filling defects and may demonstrate respiratory motion artifacts. T2 weighting may vary with different MR imaging sequences and influence MRCP findings. Incomplete imaging may create confusion regarding ductal anatomy or disease. Furthermore, MRCP yields only static images and thus may fail to depict various anomalies. Limited spatial resolution makes differentiation between benign and malignant strictures with MRCP alone extremely difficult. Susceptibility artifacts may be caused by metallic foreign bodies or gastric-duodenal gas. Fluid accumulation may produce a pseudolesion or pseudostricture, although changing the imaging angle or section thickness may be helpful. Pneumobilia may be misinterpreted as bile duct stones, and true stones may be overlooked. Pulsatile vascular compression can cause pseudo-obstruction of the bile duct. Use of both source and MIP reconstructed images obtained from different angles can help avoid cystic duct-related pitfalls. Repeat MRCP or conventional MR imaging can help avoid pitfalls related to the periampullary region. Segmental collapse of the normal main pancreatic duct may be misinterpreted as stenosis, but administration of secretin is helpful. An awareness of these pitfalls and possible solutions is crucial for avoiding misinterpretation of MRCP images.

Correlation of three-dimensional gradient echo dynamic MR imaging with CT during hepatic arteriography in patients with hypervascular hepatocellular carcinomas: preliminary clinical experience.

The purpose of this study is to elucidate the usefulness of dynamic MR study of the whole liver using 3DFISP with double dose gadolinium (Gd) enhancement in detecting enhancing lesions in 20 patients. Twenty patients with hepatocellular carcinoma (HCC) underwent 3DFISP dynamic study with double dose Gd. The demonstration of enhancing hypervascular lesions regardless of etiology was evaluated on a segment-by-segment basis with receiver operating characteristic (ROC) analysis, using findings on CT during hepatic arteriography as a gold standard. Diagnostic accuracy of 3DFISP in the detection of HCC was also evaluated. As to the demonstration of enhancing lesions, the Az value of the ROC curve was 88%. The detection rate of HCC with 3DFISP was 98%. 57% of enhancing pseudolesions were not detected on 3DFISP. We concluded that Dynamic MR study of the whole liver using 3DFISP with double dose Gd enhancement is a useful method to demonstrate hypervascular HCC.