An unusual renal vascular anomaly: common origin of arteries to the lower poles demonstrated by a computed tomography angiography using 16-slice multidetector computed tomography.

Arterial connection between the left and right kidneys is extremely rare. Only eight cases of such anomalous conditions have been reported in the world literature and all were confirmed by invasive angiography or dissection. We report a patient with this vascular anomaly clearly demonstrated by 16-slice multidetector computed tomography.

A rare case of paraovarian cancer coexisting with cancer of the fallopian tube: magnetic resonance appearance.

Primary paraovarian cancer is a rare tumor occurring in the female pelvis. Magnetic resonance imaging features of paraovarian cancer have not been previously reported. In the present report, we describe a case of paraovarian cancer coexisting with cancer of the fallopian tube and the magnetic resonance features.

Anisotropic diffusion in kidney: apparent diffusion coefficient measurements for clinical use.

The purpose of this study was to evaluate anisotropy of the kidney by measurements of the apparent diffusion coefficient (ADC) using commercially available magnetic resonance (MR) imaging. Fifty-one consecutive patients underwent diffusion-weighted echoplanar MR imaging of the upper abdomen with five different strengths of motion probing gradients (b = 1.51, 55.3, 36.6, 317, and 932 sec/mm2) applied along the z-axis. Four ADC values for the upper pole and central portion of the kidney were calculated from four different b-value ranges and compared. The ADCs for the kidney calculated in the lower b-value ranges were significantly higher than those in the higher ranges. The ADCs for the upper pole portion were significantly higher than those for the central portion except for one in the highest b-value range. Diffusion in the kidney is anisotropic, probably due to the kidney's radially oriented structures such as renal vessels and tubules.

Aberrant left gastric vein demonstrated by helical CT.

PURPOSE: Our goal was to describe the CT findings of aberrant left gastric vein (ALGV) and to evaluate the clinical significance of this vein. METHOD: Four patients in whom ALGVs were demonstrated by helical CT were examined. Each patient had either intrahepatic cholangiocarcinoma, cirrhosis with gastric varices, chronic hepatitis, or nonspecific abdominal pain. All patients underwent two phase helical CT, and the patient with cholangiocarcinoma underwent CT during arterial portography, and 3D images of the abdominal veins were obtained. RESULTS: In all patients, the ALGVs ran along the hepatogastric ligament and were directly connected with the left portal branch. In the patient with cholangiocarcinoma, the portal vein had severe stenosis by tumor invasion, and both the ALGV and the aberrant right gastric vein functioned as a collateral pathway of the portal flow into the liver. In the patient with cirrhosis, dilated ALGV with hepatofugal flow caused gastric varices. CONCLUSION: The ALGV is directly connected with the left portal branch and may play an important role in the collateral pathway of the portal system.

Differential diagnosis of early homogeneously enhancing hepatocellular carcinoma and hemangioma by two-phase CT.

PURPOSE: Our goal was to differentiate between early homogeneously enhancing hepatocellular carcinoma (HCC) and hemangioma by two-phase CT. METHOD: Two phase images of 51 HCCs and 28 hemangiomas showing homogeneous high attenuation in the first series (arterial dominant phase) were reviewed. Enhancement patterns of the lesions in the second series (parenchymal phase) were classified as homogeneous high, peripheral high, iso-, and low attenuation. The attenuation values of all and the enhancement values of some (21 HCCs and 18 hemangiomas) in the first series were calculated. RESULTS: Although low and peripheral high attenuation patterns were seen during the second series only in HCCs (n = 35), which could be used to correctly diagnose HCC, other nonspecific patterns were demonstrated in both HCCs (n = 16) and hemangiomas (n = 28). The attenuation values of 49 of the 51 HCCs and 5 of the 28 hemangiomas were below 130 HU on the first series. The enhancement values of all 21 HCCs and 3 of 18 hemangiomas were below 70 HU. Combining the enhancement patterns with a borderline attenuation value of 130 HU or borderline enhancement value of 70 HU yielded overall accuracies of 94 and 92%, respectively. CONCLUSION: The combined criteria (enhancement pattern plus attenuation or enhancement value) were useful for differentiating between early homogeneously enhancing HCCs and hemangiomas.

Segmental anatomy of the liver under the right diaphragmatic dome: evaluation with axial CT.

PURPOSE: To evaluate the segmental anatomy of the liver under the right side of the diaphragm with axial computed tomography (CT). MATERIALS AND METHODS: Forty-six patients underwent CT arteriography with selective catheterization of the right hepatic artery in 25 cases, the left hepatic artery in 12, the anterior branch of the right hepatic artery in six, the posterior branch of the right hepatic artery in five, the superior anterior branch of the right hepatic artery in 10, and the superior posterior branch of the right hepatic artery in eight. RESULTS: The boundary between the right and left lobes shifted by 16.2 degrees +/- 16.8 anteriorly, and the boundary between the anterior and posterior segments shifted by 43.9 degrees +/- 14.0 posteriorly to the line through the middle or right hepatic vein from the inferior vena cava. The top of the liver consisted of both lobes in 22 patients, only the right lobe in 17, and only the left lobe in two. Participation of segment 7 in the top was not demonstrated. CONCLUSION: The line that extends beyond the middle or right hepatic vein from the inferior vena cava does not coincide with the main or right longitudinal scissura on axial images of the upper portion of the liver.

Hepatic hemangioma: findings with two-phase CT.

PURPOSE: To characterize the appearance of hemagiomas at two-phase dynamic incremental computed tomography (CT) and to determine the cause of contrast material enhancement of adjacent parenchyma in the first series. MATERIALS AND METHODS: Contrast-enhanced CT images of 51 hemangiomas in 20 patients were reviewed. Enhancement patterns of hemangiomas in the first series were classified as homogeneous high, peripheral high, and low attenuation; in the second series, as homogeneous high, peripheral high, iso-, and low attenuation. Correlations between arterioportal shunts and early parenchymal enhancement were evaluated in 45 hemangiomas in the 17 patients who underwent angiography. RESULTS: Thirty-two hemangiomas progressively became enhanced. Four had low and eight had homogeneous high attenuation in both series. Seven changed from homogeneous high to isoattenuation. Early parenchymal enhancement was well correlated with presence of arterioportal shunt. CONCLUSION: Low-attenuation hemangiomas and those that changed from homogeneous high to isoattenuation are atypical and difficult to differentiate from other neoplasms. Most early parenchymal enhancement is caused by associated arterioportal shunts.

Hepatic pseudolesion in the left lobe around the falciform ligament at helical CT.

PURPOSE: To determine the prevalence and possible cause of pseudolesions in the left hepatic lobe around the falciform ligament at hepatic helical computed tomography (CT). MATERIALS AND METHODS: Portal venous-dominant CT scans of 472 consecutive patients were reviewed. CT of the left hepatic lobe was performed after injection of contrast material into the portal vein in 73 patients, the hepatic artery in 32, and the internal thoracic artery in four. The scans were compared with those obtained at helical CT, and the findings were analyzed. RESULTS: Pseudolesions were seen on 64 (14%) of 472 helical CT scans and correlated well (accuracy, 96%) with portal perfusion defects. They were not more enhanced than the surrounding liver parenchyma at CT arteriography with hepatic artery injection but were enhanced in two patients at CT arteriography with internal thoracic artery injection. CONCLUSION: Pseudolesions are caused by portal perfusion defects and may receive an aberrant blood supply.

The use of CT and scintigraphy in diagnosing a cystic ameloblastoma of the jaw.

The results of CT and bone scintigraphy of eight patients with a histologically proven cystic ameloblastoma of the jaw are reviewed. CT imaging revealed unilocular and multilocular cystic lesions with well-defined thin cystic borders in all patients. CT also detected increased density in the bone marrow adjacent to the cystic radiolucent lesion, suggesting that the ameloblastoma had spread into the cancellous bone. Further, nuclear bone scans showed a doughnut-shaped pattern in all cases and radioactivity beyond the cystic wall, indicating intramedullary extension of the ameloblastoma. The use of these two modalities was found to be complementary in delineating the full nature and extent of the pathologic lesion.

Small hepatocellular carcinomas: two-phase dynamic incremental CT in detection and evaluation.

PURPOSE: To compare dynamic incremental computed tomography (CT) with other techniques in detecting and evaluating small hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Two-phase (early vascular and parenchymal) dynamic incremental CT of the entire liver and ultrasonography (US) were performed in 184 patients with chronic liver disease. Thirty patients had 36 small HCCs (less than 30 mm in diameter); 27 of these 30 patients also underwent CT after intraarterial injection of iodized oil, and the results were compared. RESULTS: The HCC detection rate was 92% with dynamic incremental CT, 69% with US, and 81% with iodized oil-enhanced CT. Of six well-differentiated HCCs, two were detected with the first dynamic incremental CT series and two with iodized oil-enhanced CT, whereas all were detected with the second dynamic incremental CT series and five with US. CONCLUSION: Two-phase dynamic incremental CT was superior to the other techniques and is a useful and easy procedure for routine follow-up of patients with chronic liver disease.