Search PubMed⌕ Search

Biomedical subjects

M Kadoya

Publications and source records attributed to M Kadoya.

At least 127 records · Page 7Linked to original sources

Segmental hyperintensity on T1-weighted MRI of the liver: indication of segmental cholestasis.

The purpose of this study was to determine the relationship between segmental hyperintensity of the liver on T1-weighted images and segmental cholestasis in patients with obstructive jaundice. T1-weighted and T2-weighted MR images were obtained of 73 patients with obstructive jaundice caused by various diseases. Fat-suppressed T1-weighted images were also obtained of 10 patients. Eleven patients with segmental intrahepatic bile duct dilatation (cholestasis) showed segmental hyperintensity on T1-weighted images and/or fat-suppressed T1-weighted images and no signal intensity difference on T2-weighted images. Sixty-two patients with widespread intrahepatic bile duct dilatation showed no intensity difference on T1-weighted and T2-weighted images (P < .01). Segmental hyperintensity on T1-weighted images was correlated with intrahepatic cholestasis.

Adult↗

Biliary cystadenoma with mesenchymal stroma of the liver: correlation between unusual MR appearance and pathologic findings.

We reported a case of the biliary cystadenoma of the liver. The cystic mass had lobulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid.

Adenoma, Bile Duct↗

Successful embolization of a large superior gluteal artery pseudoaneurysm emerging during anticoagulant therapy.

Gross hemorrhage is the most serious complication of anticoagulant therapy. We report the discovery and treatment of a large pseudoaneurysm of the superior gluteal artery in one patient who had been receiving oral anticoagulant therapy. We diagnosed the pseudoaneurysm by contrast-enhanced computed tomography, and embolized the artery with stainless steel coils. The exact cause of the pseudoaneurysm remains unclear, however, minor trauma appears most likely.

Aneurysm, False↗

A new coaxial needle system, hepatic artery targeting wire, and biplane fluoroscopy to increase safety and efficacy of TIPS.

To improve safety and efficacy of the transjugular intrahepatic portosystemic shunt (TIPS) procedure, we introduced a new, thin-needle (21-gauge long PTC needle) puncture technique using biplane fluoroscopy and targeting of a guidewire tip in the right hepatic artery. After puncture of the right portal vein, a 0.016-inch guidewire was inserted into the portal vein, followed by a 4 Fr dilator. The 4 Fr dilator allowed introduction of a 0.035-inch working guidewire. We successfully performed TIPS in seven patients with postnecrotic cirrhosis using this technique and encountered no technical difficulties or complications.

Fluoroscopy↗

Detection of hypervascular hepatocellular carcinoma by using spiral volumetric CT: comparison of US and MR imaging.

BACKGROUND: Most hepatocellular carcinomas (HCCs) are hypervascular and arise in the liver with chronicity. Spiral volumetric CT (SVCT) is a new rapid-scan technique that offers whole-liver scanning during the arterial-dominant phase. The main aim of the present study is to evaluate the detectability of hypervascular HCC with SVCT as compared with ultrasonography (US) and magnetic resonance (MR) imaging. METHODS: Forty-three hypervascular HCCs in 512 patients with chronic liver disease were examined with US, precontrast SVCT, postcontrast SVCT during the arterial-dominant phase (CT-ADP) and during the equivalent-phase (CT-EP) noncontrast MR imaging and angiography including SVCT during arteriography and arterial portography. Angiographic and follow-up findings were used as the gold standard if the lesion was not confirmed histologically. RESULTS: The sensitivity was 61% with precontrast CT, 84% with CT-ADP, 58% with CT-EP, 70% with US, 72% with MR, and 95% with the combination of these five modalities. Five HCCs (12%) were detected with only CT-ADP. The vascularity of HCC was correctly evaluated as hypervascular in 38 nodules (88%) with the combination of precontrast CT and CT-ADP. CONCLUSIONS: We suggest that the combination of precontrast SVCT and CT-ADP is an essential modality to screen for HCC in patients with chronic liver disease. CT-EP did not contribute to the detection of hypervascular HCC.

Adult↗

Transjugular intrahepatic portosystemic shunt after previous recanalization of a chronically thrombosed portal vein via a transmesenteric approach.

We report a cirrhotic patient with complete occlusion of the portal vein with marked cavernous transformation due to chronic thrombosis in whom a transjugular intrahepatic portosystemic shunt (TIPS) was successfully created after direct minilaparotomy mesenteric vein catheterization, lysis and aspiration of the thrombus, and stenting in the portal vein. The methods used, we believe, provide a new technique for performing TIPS in chronically thrombosed portal veins in which previously no effective surgical therapeutic options were available.

Adult↗

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↗

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↗

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↗

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↗

Presacral ganglioneuroma arising in an elderly man with persistent constipation.

Presacral ganglioneuroma in a 70-year-old man with persistent constipation and its features on computed tomography, magnetic resonance, and endoscopic ultrasonography are presented. Barium enema study and laparotomy showed that constipation was caused mainly by extrinsic compression from this tumor. Computed tomography, magnetic resonance, endoscopic ultrasonographic features such as well-defined solid tumor with a cystic component and punctate calcifications may facilitate early diagnosis of this rare tumor.

Aged↗

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↗

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↗