Biomedical subjects
Publications and source records attributed to H Honda.
A case of primary lymphoma in the porta hepatis is presented here. Cholangiography, angiography, ultrasonography and computed tomography suggested the presence of a mass in the porta hepatis, but all these failed to demonstrate the tumor clearly. Magnetic resonance imaging was very useful in defining the characteristics of the tumor and in delineating its extent, though it was not specifically diagnostic.
BACKGROUND: To elucidate the metallic factors contributing to the signal intensities of hepatocellular carcinoma (HCC) on T1-weighted magnetic resonance (MR) images and to determine whether or not changes in signal intensity contribute to the diagnosis of histological grading of HCC. METHODS: In 35 patients immediately after surgery, the quantities of water, lipid, copper (Cu), iron (Fe), and manganese (Mn) were determined in HCCs and the surrounding hepatic parenchyma. The correlations among these findings, the histopathological findings, and the signal intensities of T1-weighted MR images were evaluated. RESULTS: Among the 35 HCCs, 12 (34%) were of high intensity, 14 (40%) were isointense, and 9 (26%) were of low intensity on T1-weighted images versus the surrounding hepatic parenchyma. The paramagnetic ions, which contributed to the signal intensity patterns, were assumed to be Cu in HCCs (30.5 +/- 52.9 microg/g ww), and Fe in the livers (106.2 +/- 86.8 microg/g ww) and HCCs (87.7 +/- 49.1 microg/g ww). In 12 HCCs with high intensity, one was grade I, eight were grade II, and three were grade III according to Edmondson-Steiner's histopathological classification. CONCLUSIONS: Signal intensity and signal intensity patterns alone cannot be signs of low-grade malignancy because of the Fe in livers and in HCCs.
BACKGROUND: Although helical computed tomography (HCT) has been widely employed for the evaluation of pancreatic tumors, its capability in the diagnosis of peripancreatic arterial invasion has not been established. METHODS: HCT with a sequential cine-display was carried out in 34 patients with solid pancreatic tumors and 28 control subjects without angiographic abnormality. The HCT scans were compared with angiograms. RESULTS: All major arteries (celiac, superior mesenteric, splenic, gastroduodenal) and superoanterior pancreaticoduodenal arteries were well demonstrated by HCT in control subjects. However, posterior pancreaticoduodenal arcades and other smaller arteries were poorly identified. Although 19 major arterial invasions were equally diagnosed by HCT and angiography in patients with pancreatic tumors, only 4 of 11 minor arterial invasions were correctly diagnosed by HCT. CONCLUSIONS: Although HCT has some limitations in the evaluation of minor peripancreatic arteries, it can provide enough information for making a decision about conducting pancreatic surgery.
BACKGROUND: To compare the value of helical computed tomography (CT) and various pulse sequences of magnetic resonance (MR) imaging in the detection and staging of small pancreatic adenocarcinoma. METHODS: Small pancreatic adenocarcinomas (< or = 2 cm in diameter) in eight patients were evaluated with both helical CT and MR imaging. Five MR imaging pulse sequences that included fat-suppressed T1-weighted images and dynamic study using fast multiplanar spoiled gradient-recalled technique were compared for the tumor detectability. To evaluate the tumor vascularity, angiographic findings were also investigated. RESULTS: Helical CT delineated the tumor in five cases, and MR imaging depicted the tumor in seven cases. MR imaging could detect the tumor of 0.8 cm in diameter clearly. Although helical CT and dynamic MR imaging missed the tumor of 2 cm with relative hypervascularity, fat-suppressed T1-weighted MR imaging demonstrated it precisely. As for the tumor staging, MR imaging was equal or slightly superior to helical CT. CONCLUSION: MR imaging is the first modality of choice to evaluate small pancreatic adenocarcinoma, and fat-suppressed T1-weighted images and dynamic study must be performed.
A case of uterine lipoleiomyoma demonstrated on computed tomography (CT) and magnetic resonance imaging (MRI) is described and usefulness of MRI is discussed in diagnosing this entity.
We report a case of a chronic expanding hematoma caused by an angiomyolipoma of the spleen in a patient diagnosed with tuberous sclerosis in infancy. Computed tomography showed large bilateral renal angiomyolipomas. A splenic mass that increased in size during the follow-up period of 62 months was also noted. A large subcapsular hematoma of the spleen finally developed, and a splenectomy was performed. The splenic mass consisted of a chronic hematoma with prominent granulation tissue, which was considered to be caused by repeated bleeding from a small angiomyolipoma in the spleen.
A rare case with a pseudolesion in segment II of the liver observed on computed tomography (CT) during arterial portography caused by the aberrant left gastric venous drainage is presented. Close observation of the celiac angiography was helpful in recognizing this pseudolesion. Selective catheterization of the left gastric artery and CT during its venous phase confirmed the etiology of the pseudolesion.
Preoperative chemical-shift magnetic resonance images in a 56-year-old man suggested the presence of microscopic fat in the tumor. The surgical specimen showed a granular-cell renal cell carcinoma with papillary architecture, associated with abundant fat-containing foamy histiocytes in the interstitium. The radiologist should include this entity in the differential diagnoses of renal tumors that contain microscopic fat.
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.
A 43-year-old non-cirrhotic woman suffered from encephalopathy caused by an extrahepatic portosystemic shunt between the ileal vein and inferior vena cava via the right gonadal vein. Percutaneous transcatheter embolization with stainless steel coils was performed by the retrograde systemic venous approach. Encephalopathy improved dramatically.
Subjects were required to perceptually judge the location of flash targets presented at the time of a saccade at various positions scattered two-dimensionally on a dimly illuminated structured background. The saccade-contingent mislocalization was shown only in the direction parallel to the saccade, and not in the direction perpendicular to the saccade. In addition, the mislocalization under the "illuminated background" condition was different in several respects from that observed when targets were presented in the dark. It was suggested that the mislocalization is successfully explained by assuming three physiological and cognitive processes: a sluggish activity of the extraretinal eye position signal, visual cues from the visible background, and selective inattention to image displacements.
Employing immunohistochemical techniques and a panel of monoclonal antibodies that recognize rat cells of monocyte/macrophage lineage, we have demonstrated that cells labeled with these antibodies are widely distributed throughout the parenchyma of the rat brain. These cells have a remarkable microglial morphology and form phenotypically heterogenous populations. Double immunoperoxidase staining with the monoclonal antibody and anti-von Willebrand factor antiserum, which recognizes vascular endothelial cells, revealed that these cells are located exclusively at perivascular sites in the adult brain. These observations indicate that the microglial cells are perivascular cells of the monocyte/macrophage lineage, and may be intimately involved in various immunopathogenic conditions of the central nervous system.
Malignant histiocytoma of the liver, a rare liver tumor, has not been reported in the radiological literature. The differential diagnosis of liver mass should be expanded to include primary malignant fibrous histiocytoma. Embolization of the mass was ineffective.
A 34-yr-old man with a liver mass was referred to the hospital. The mass showed temporary spontaneous regression during the follow-up, however, subsequent regrowth of the tumor prompted surgical resection. The specimen revealed intrahepatic cholangiocarcinoma with two distinct components which had been clearly demonstrated on serial CT. Spontaneous resolution of a lesion does not necessarily suggest the lesion's benign, self-limiting entity. Intrahepatic cholangiocarcinoma should be included in the tumors that could spontaneously regress.
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.
A rare case of transitional cell carcinoma (TCC) with extension into the renal vein and inferior vena cava (IVC) is presented. Computed tomography, magnetic resonance imaging, and angiography successfully delineated tumor thrombus in the right renal vein and IVC. TCC should be included in the differential diagnosis of renal tumors that can cause IVC thrombosis.
A case of radiologically identified molar invasion into extensive arteriovenous shunts (AVSs) is described. CT and MRI revealed a large uterine mass, accompanied by multiple AVSs. Dynamic MRI and pelvic angiography demonstrated multiple trophoblastic cysts invading into the AVSs. Resected specimen confirmed the diagnosis of invasive mole. Dynamic MRI was very useful in determining the etiology of AVS.
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.