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Biomedical subjects

M Kadoya

Publications and source records attributed to M Kadoya.

At least 145 records · Page 8Linked to original sources
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↗
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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↗
PubMedDate not supplied

Transjugular intrahepatic portosystemic shunt: histologic and immunohistochemical study of autopsy cases.

PURPOSE: To assess the histologic findings associated with stenosed and occluded transjugular intrahepatic portosystemic shunt (TIPS) tracts. METHODS: Four TIPS tracts within three autopsy livers were histologically studied for vascular components by routine staining and immunohistochemical staining. TIPS had been performed for bleeding from esophageal varices in patients with cirrhosis of the liver. RESULTS: Two TIPS, examined on days 4 and 53, showed occlusion by fibrin thrombus. In the former, no endothelial cells were detected, but coagulative necrosis of hepatocytes was found in the surrounding liver. In the latter, bile pigments were seen on the luminal surface. In the two other TIPS without tract occlusion, examined on days 49 and 293, a layer of endothelial cells, proliferation of smooth muscle cells, and deposition of an extracellular matrix such as collagen were confirmed. In the tract examined on day 293, there was protrusion of hepatocytes into the lumen through the stent wires. CONCLUSION: Short- and midterm TIPS occlusions were caused by thrombus forming after necrosis of hepatocytes and bile leakage, respectively. Long-term TIPS stenosis was associated with a combination of pseudointimal hyperplasia and ingrowth of hepatocytes.

Cell Division↗
PubMedDate not supplied

Malignant esophageal stricture and fistula: palliative treatment with polyurethane-covered Gianturco stent.

PURPOSE: To evaluate the effectiveness of a polyurethane-covered Gianturco stent in the palliative treatment of malignant esophageal stricture and fistula. PATIENTS AND METHODS: Twenty-seven patients with recurrent stricture (n = 24), fistula formation (n = 8), or both (n = 5) underwent palliative treatment for aphagia (n = 15) or dysphagia (n = 12). Eight patients had fistulas to the respiratory tract or mediastinum. A 15-F delivery sheath system was passed through the stricture; the inner dilator was removed, and the stent was compressed into the sheath and advanced with a pusher catheter. Follow-up included chest radiography for 3 days and monthly esophagography or endoscopy. RESULTS: Covered stents occluded fistulas and opened strictures in 100% of patients. Food intake was upgraded to liquids in 7% of patients, to soft foods in 37% and to regular foods in 56%. New stricture or fistula occurred in 4% and 7% of patients, respectively. Stent migration occurred in 15% of patients. Twenty-one patients died after stent placement, and average life expectancy was 11 weeks. CONCLUSION: A polyurethane-covered Gianturco stent is effective in the palliation of advanced malignant esophageal strictures and fistulas.

Aged↗
PubMedDate not supplied

Dynamic computed tomography during arterial portography: the most sensitive examination for small hepatocellular carcinomas.

The efficacy of dynamic sequential CT with table incrementation during arterial portography (DSCTI-AP) in the detection of small hepatocellular carcinomas (HCC) (less than 3 cm in diameter and less than three in number) was analyzed in comparison with other imaging methods including radionuclide (RN) liver scans, ultrasound (US), CT, selective celiac angiography (SCA), and infusion hepatic angiography (IHA). The sensitivity of each study in detecting 19 cases of small HCC was as follows: RN, 16%; US, 63%; CT, 58%; SCA, 58%; IHA, 83%; and DSCTI-AP, 95%. Three of 19 cases were diagnosed only by DSCTI-AP and one case that could not be visualized by DSCTI-AP was opacified by IHA. Dynamic sequential CT with table incrementation during arterial portography was superior to IHA in visualizing small HCCs.

Adult↗
PubMedDate not supplied

Height of normal pituitary gland on MR imaging: age and sex differentiation.

Measurement of the pituitary height was performed on magnetic resonance (MR) images of 213 subjects with no known or suspected pituitary and/or hypothalamic disorders. Midsagittal, T1-weighted images were used for measurements and mean heights in each age and sex group were obtained. In the 10 to 69 year range, the pituitary heights were greater in females than in males. The groups of 0-9 years of both genders showed the minimum mean pituitary height. The maximum of the mean height was observed in the 10 to 19 year age groups of both genders. The height gradually decreased with increasing age after age 20 years. There were no subjects with a height of greater than or equal to 9.0 mm in females or greater than or equal to 8.0 mm in males. There was a marked discrepancy between MR and autopsy findings in the older subjects, probably related to the upward concavity that is often encountered in the aged gland. Because of this concavity, the midsagittal MR measurement will induce underestimation of the whole gland.

Age Factors↗
PubMedDate not supplied

Transient subpleural curvilinear shadow caused by pulmonary congestion.

We present two cases of transient subpleural curvilinear shadows (SCSs) on CT caused by pulmonary congestion. Subpleural curvilinear shadows, which are usually visible in the middle or lower dorsal lung field on CT, have been reported as the initial finding of pulmonary fibrosis. But SCS is not a specific finding since pulmonary congestion may be one cause of it.

Aged↗
PubMedDate not supplied

MR imaging of spinal neurinomas with pathological correlation.

Eight patients with nine spinal neurinomas were examined with magnetic resonance (MR) imaging. We attempted to correlate MR images with the gross and microscopic characteristics of the tumors. On T1-weighted images (T1WIs) all tumors were iso- to slightly hyperintense to CSF, although two comprised hyperintense areas. On the T2-weighted pulse images (T2WIs), available for seven tumors, two tumors were markedly and two relatively hyperintense to CSF. Three tumors exhibited mixed signal intensity. On macroscopic examination, the markedly hyperintense areas on T2WIs corresponded to the cystic portions and relatively hyperintense areas to the solid portions. Areas that were hypointense on T2WIs and isointense or markedly hyperintense on T1WIs corresponded to hemorrhage. On microscopic examination it was impossible to establish a correlation between Antoni A and Antoni B tissue types and features recognized on T1WIs and T2WIs. Gadolinium-diethylenetriamine pentaacetic acid enhanced T1WIs were performed in four patients with five tumors. All tumors enhanced, demonstrating the tumor contours and the cystic degeneration within.

Adult↗
PubMedDate not supplied

MR imaging of neurilemoma arising from the renal hilus.

The authors present the radiologic findings of a neurilemoma arising from the kidney. Ultrasound, CT, and angiography could not exclude the diagnosis of renal cell carcinoma (RCC). Magnetic resonance (MR) imaging at 1.5 T showed an isointense tumor on T1-weighted images and a high signal intensity on T2-weighted images compared with normal renal parenchyma. The MR findings were helpful in the differentiation from RCC.

Carcinoma, Renal Cell↗
PubMedDate not supplied

Pericallosal lipomas: MR features.

We report on six cases of pericallosal lipomas. The T1-weighted sagittal images best demonstrated the relationship between the lipoma and the corpus callosum. In four cases the lipomas surrounded the splenium of the corpus callosum and in two cases the tumors were situated posteriorly and caudally to the splenium. In no case did we encounter an exclusively dorsal pericallosal localization.

Adolescent↗
PubMedDate not supplied

MR imaging in idiopathic portal hypertension.

Magnetic resonance imaging was performed in four patients with biopsy proven idiopathic portal hypertension (IPH). The MR images show proximity of medium-sized intrahepatic vessels to each other and to the liver surface in all patients. Small vessels running parallel to the second order branches of the intrahepatic portal vein are commonly seen as collateral pathways of portal flow in IPH and were seen in two patients. These findings were clearly demonstrated on gradient-recalled echo images. Intrahepatic periportal abnormal high intensity was seen in all patients on T2-weighted images and may reflect abnormalities in the portal tracts such as fibrous enlargement and increase in the number of vascular channels. Tiny low-intensity nodules sometimes observed in liver cirrhosis were not seen in any patient. Magnetic resonance was a useful noninvasive method in the differentiation of IPH from liver cirrhosis.

Aged↗