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Biomedical subjects

O Matsui

Publications and source records attributed to O Matsui.

At least 199 records · Page 11Linked to original sources
PubMedDate not supplied

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.

Aged↗
PubMedDate not supplied

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.

Cholangiocarcinoma↗
PubMedDate not supplied

Intrapancreatic accessory spleen: evaluation by CT arteriography.

BACKGROUND: Intrapancreatic accessory spleens are frequently confused with primary pancreatic tumors, and differentiation from neoplastic lesions is important to avoid an unnecessary laparotomy. We present three cases of intrapancreatic accessory spleen evaluated by computed tomographic arteriography (CTA) and discuss the characteristic findings. METHODS: CTA was performed, followed by digital subtraction angiography, with an injection of contrast material through a 4-F catheter placed in the celiac artery. Single-level dynamic CTA was also performed in two patients with a 30-s continuous scan in one breath-hold. RESULTS: CTA clearly demonstrated early inhomogeneous enhancement of the lesion, similar to the splenic parenchyma. On single-level dynamic CTA, inhomogeneous enhancement of the lesion in the early phase was diminished in the late phase. Multiplanar reformatted images obtained in two cases showed the deep cleft between the lesion and the pancreas, which suggested that the lesion was originally extrapancreatic. CONCLUSIONS: These two findings on CTA, inhomogeneous enhancement of the lesion and the deep cleft between the lesion and the pancreas, may help to confirm the diagnosis of an intrapancreatic accessory spleen.

Adult↗
PubMedDate not supplied

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.

Diagnosis, Differential↗
PubMedDate not supplied

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.

Bile Ducts, Intrahepatic↗
PubMedDate not supplied

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.

Aged↗
PubMedDate not supplied

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.

Adult↗
PubMedDate not supplied

Peribiliary cysts in cirrhotic liver: observation on computed tomography.

BACKGROUND: To analyze the frequency and number of suspected peribiliary cysts in cirrhotic liver on computed tomography (CT). METHODS: Three hundred forty-six cases with clinically diagnosed liver cirrhosis (LC) and 307 cases with clinically diagnosed non-LC were subjected to the study. The frequency and number of suspected peribiliary cysts on CT were compared between the two groups. The existence of peribiliary cysts was suggested when a cyst was observed around the second- to fourth-order branches of the intrahepatic portal vein. RESULTS: Peribiliary cysts were suggested on CT in 31 of 346 cirrhotic livers (9.0%) and 10 of 307 noncirrhotic livers (3.3%). This difference in the frequency of peribiliary cysts was statistically significant (chi2, p < 0.01). Multiple peribiliary cysts were seen in 71% of cirrhotic patients with peribiliary cyst. The size of peribiliary cysts was smaller than 1.5 cm in diameter. CONCLUSION: Peribiliary cyst is radiologically observed more frequently in cirrhotic liver than in noncirrhotic liver and is occasionally multiple.

Adult↗
PubMedDate not supplied

Gallbladder varices: demonstration of direct communication to intrahepatic portal veins by color doppler sonography and CT during arterial portography.

Gallbladder varices were correctly diagnosed by color Doppler sonography and computed tomography during arterial portography (CTAP) in two patients with portal vein thrombosis. One patient with multiple hepatocellular carcinomas showed extrahepatic and intrahepatic portal vein occlusion by a tumor thrombus. The other patient, with liver cirrhosis, had a portal vein thrombosis. Color Doppler sonography clearly showed the portal vein occlusion, cavernous transformation of collateral veins, and gallbladder varices that drained into the intrahepatic portal venous branches. The intrahepatic portal venous branch, connecting to the gallbladder varices, exhibited reverse flow from the periphery to the hilum of the liver. CTAP also demonstrated gallbladder varices communicating directly with the intrahepatic portal vein branches in both patients. Gallbladder varices developed as a venous collateral because of extrahepatic portal vein occlusion. Color Doppler sonography and CTAP are useful for detecting these varices and planning biliary surgery in patients with portal vein thrombosis.

Aged↗
PubMedDate not supplied

Fatty infiltration of the liver distal to a metastatic liver tumor.

We report a case of focal fatty infiltration of the liver parenchyma adjacent to a metastatic liver tumor from an islet cell tumor. The decreased portal flow by the tumor and insulin produced by the tumor cells might be causes of focal fatty infiltration.

Adenoma, Islet Cell↗
PubMedDate not supplied

Aberrant gastric venous drainage into the medial segment: demonstration by color Doppler sonography.

BACKGROUND: Aberrant gastric venous drainage (AGVD) into the posterior edge of the medial segment of the liver (segment IV) is the main cause of pseudolesion on computed tomography (CT) during arterial portography. We estimated the prevalence of AGVD into the medial segment of the liver with color and power Doppler ultrasound (US). METHODS: Screening gray-scale and color Doppler and power Doppler US were performed in 100 consecutive patients. AGVD was defined as a venous structure that ascended parallel to the main portal vein and drained independently into segment IV. RESULTS: AGVDs were observed in eight of 100 patients (8%) with color and power Doppler US. Power Doppler US depicted these veins more clearly than did color Doppler US. Gray-scale US did not show any AGVDs. Two of eight patients with AGVDs detected by color Doppler US underwent celiac arteriography and CT during arterial portography (CTAP). In these two patients, celiac arteriography directly demonstrated AGVDs draining into segment IV, which revealed nontumorous perfusion defects (pseudolesions) on CTAP. CONCLUSION: Color and power Doppler US are useful imaging methods for demonstrating AGVDs.

Congenital Abnormalities↗
PubMedDate not supplied

Obstructive jaundice caused by lymphangitis carcinomatosa of bile duct wall from gastric carcinoma.

We report a case of advanced gastric carcinoma presenting with obstructive jaundice. Computed tomography showed marked lymphadenopathy in the hepatoduodenal ligament and concentric bile duct wall thickening. Histologically, extrahepatic bile duct wall was thickened due to submucosal lymphangitic spread of gastric carcinoma (lymphangitis carcinomatosa). Lymphangitis carcinomatosa may be considered when extrahepatic bile duct wall thickening is seen in patients with obstructive jaundice.

Adenocarcinoma↗
PubMedDate not supplied

CTAP in budd-chiari syndrome: evaluation of intrahepatic portal flow.

BACKGROUND: To assess the intrahepatic portal flow in patients with Budd-Chiari syndrome (BCS) by computed tomography (CT) during arterial portography (CTAP). METHODS: Five patients with BCS [with (n = 3) and without (n = 2) inferior vena cava (IVC) obstruction] underwent both CTAP and postcontrast CT following CTAP. CTAP and postcontrast CT after angioplasty were also performed in one patient. Findings on CTAP and postcontrast CT were analyzed retrospectively. RESULTS: Patients with IVC obstruction and a patent large hepatic vein showed homogeneous hepatic enhancement on CTAP. Patients without IVC obstruction and with no patent large hepatic veins showed heterogeneous hepatic enhancement, which consisted of patchy enhancement and more definite enhancement in the central part of the liver. On postcontrast CT, the patchy enhancement was enlarged compared with that on CTAP in these patients. The heterogeneous hepatic enhancement became homogeneous in the patient who underwent angioplasty. CONCLUSION: We suggest that the more marked the blood congestion, the more heterogeneous the hepatic enhancement becomes on CTAP. Heterogeneous hepatic enhancement on CTAP is seen in such cases without any patent hepatic veins.

Adult↗
PubMedDate not supplied

Delayed MR imaging of the liver: correlation of delayed enhancement of hepatic tumors and pathologic appearance.

BACKGROUND: The value of delayed magnetic resonance (MR) imaging (6 min) and ultradelayed MR imaging (1-4 h) for differentiating of hepatic tumors was studied. METHODS: Postcontrast delayed and ultradelayed MR images were obtained after administration of 0.1 mmol/kg of Gd-DTPA in 30 patients with various malignant hepatic tumors. RESULTS: Delayed enhancement in the center of the tumors was seen in 13 patients on the delayed MR images and in 22 patients on the ultradelayed MR images. On the ultradelayed images, peripheral hypointense rim was seen in 12 patients and central focal hypointense area was seen in eight patients. Pathologically, the portion showing delayed enhancement corresponded to abundant fibrous stroma, the hypointense rim to rich proliferation of tumor cells, and the central hypointense areas to coagulative necrosis. CONCLUSION: Ultradelayed MR imaging can characterize different tissue components within various hepatic tumors.

Aged↗
PubMedDate not supplied

Giant hyperplasia of the caudate lobe of the cirrhotic liver: correlation with an anomaly of the caudate portal branch.

Different imaging appearances of giant hyperplastic change of the caudate lobe of the liver are presented in a patient with liver cirrhosis. The mass like caudate lobe was isoechoic on ultrasound, hypodense on postcontrast computed tomography (CT), hyperintense on T1-weighted magnetic resonance, images and isointense on T2-weighted images. These imaging findings are similar to those of dysplastic nodule in cirrhotic liver. The caudate lobe received normal portal flow on CT during arterial portography, but superior mesenteric arteriography showed precocious or early division of the caudate portal branch. We suspect that caudate hyperplastic change may be correlated to anomalous caudate portal vein branch.

Humans↗
PubMedDate not supplied

Right hepatic arterial supply to the posterior aspect of segment IV of the liver: analysis by CT during hepatic arteriography.

OBJECTIVE: To examine the frequency of the right hepatic arterial supply to the posterior aspect of segment IV (PASIV) of the liver shown on computed tomography (CT) during hepatic arteriography (CTHA). MATERIALS AND METHODS: Seventy-four patients who underwent CTHA from the right and/or left hepatic artery were studied. The right arterial supply to the PASIV was determined when the PASIV was stained on CT during right hepatic arteriography without any opacified arteries originating from the right hepatic artery and distributing to segment IV through the left hepatic hilum or when no staining was seen in the PASIV on CT during left hepatic arteriography. The frequency of the right hepatic arterial supply to the PASIV demonstrated on CTHA was analyzed. RESULTS: In six of 74 patients (8%), the PASIV was supplied from the right hepatic artery. CONCLUSION: This PASIV was supplied by the right hepatic artery in a significant proportion of cases.

Adult↗