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Biomedical subjects

G Uchiyama

Publications and source records attributed to G Uchiyama.

At least 19 recordsLinked to original sources
PubMed1992

[MR imaging of amyotrophic lateral sclerosis].

Magnetic resonance imaging (MR imaging) provides a sensitive method for mapping the normal and pathological distribution of iron in the brain. High field strength MR imaging (1.5 T) was used to evaluate eight patients with amyotrophic lateral sclerosis (ALS) and 49 neurological normal control patients. All eight ALS patients showed decreased signal intensity in the motor cortex on T2-weighted images, while only one of the normal control patients showed this finding. The results suggested that the decreased signal intensity in the motor cortex in ALS was caused by the deposition of iron in this area.

Adult↗
PubMed1992

MR imaging of malignant mesenchymal tumors of the liver.

Magnetic resonance (MR) features of five primary malignant mesenchymal neoplasms (plasmocytoma, leiomyosarcoma, undifferentiated sarcoma, epithelioid hemangioendothelioma, and angiosarcoma) of the liver were reported. All tumors were hypointense on T1-weighted images and hyperintense on T2-weighted images. No halo and intravenous extension were noted. A target appearance was revealed in epithelioid hemangioendothelioma. MR findings of angiosarcoma were essentially the same as those of cavernous hemangiomas (markedly hyperintense with hypointense linear septa on T2-weighted images). MR findings of these rare hepatic malignancies were nonspecific, although they were quite different from those of typical hepatocellular carcinomas. This study suggested that MR differentiation of primary hepatic mesenchymal tumors from other common benign and malignant neoplasms was difficult; however, the number of studied cases was limited.

Adolescent↗
PubMed1992

A new liver functional study using Tc-99m DTPA-galactosyl human serum albumin: evaluation of the validity of several functional parameters.

Several parameters calculated with a new functional imaging agent for the liver, Tc-99m DTPA-galactosyl human serum albumin, were evaluated in 9 patients with liver cirrhosis, one with hepatocellular carcinoma, and five with both liver cirrhosis and hepatocellular carcinoma. LU3, which represents the cumulative uptake of the tracer from 3 to 4 minutes after injection, showed a strong correlation (r = 0.858, p = 0.0001) with LHL15, which represents the count ratio for the liver to sum for the liver and heart 15 minutes after injection of the tracer. It also showed a strong correlation (r = -0.896, p = 0.0001) with the indocyanine green retention rate (ICGR15). Regional ICGR15 is therefore calculable from the regional LU3. GSAR15, which represents the radioactivity of the tracer retained in the blood 15 minutes after injection, showed a strong correlation (r = 0.878, p = 0.0001) with HH15, which represents the count ratio for the heart 15 minutes after injection of the tracer divided by the count for the heart 3 minutes after injection. In conclusion, LU3 and GSAR15 are interesting and promising parameters for assessing liver function.

Adult↗
PubMed1992

[Phase III multi-center clinical study on 99mTc-GSA, a new agent for functional imaging of the liver].

A multi-center clinical study was performed in patients with hepatic disorders to evaluate the clinical usefulness of 99mTc-DTPA-galactosyl serum albumin (99mTc-GSA), a new radiopharmaceutical which binds to asialoglycoprotein receptors on hepatocytes. The blood clearance and hepatic accumulation were evaluated on the basis of the dynamic data and serial hepatic images obtained for 20 min after 99mTc-GSA injection. The blood clearance and hepatic accumulation indices of 99mTc-GSA demonstrated the followings. 1) In acute liver diseases, these indices reflected the clinical features of the disease and correlated with the laboratory test indices for the blood coagulation system. 2) In chronic liver diseases, these indices changed in direct proportion to the progression of the hepatic disorder and correlated well with the conventional laboratory test results. 3) In obstructive jaundice, these indices aided evaluation of the liver function despite the high serum bilirubin level. 4) The indices reflected the change in the number of hepatocytes before and after hepatectomy. The scintigraphic findings with 99mTc-GSA permitted both functional and morphological evaluations of the liver and provide additional information compared with conventional liver scintigraphy. These results suggest that 99mTc-GSA scintigraphy may be useful for evaluating both the function and morphology of the liver from a new viewpoint of receptor-mediated accumulation.

Drug Evaluation↗
PubMed1991

[Effect of intravenous fructose load on the P-31 MR spectrum of the cirrhotic liver].

Changes in metabolic state of the liver after intravenous fructose (250 mg/kg) load were evaluated by P-31 MR spectroscopy. Study was performed in eight healthy volunteers and six patients with liver cirrhosis. In the spectra of the cirrhotic livers the fructose load caused no significant increase in PME peak, which suggested that fructose metabolism of the cirrhotic livers had impediments before the fructose-1-phosphate stage. Also shown in the spectra of the cirrhotic livers was the significant drop of Pi, PDE, and ATP peaks. This might reflect the low concentration of Pi, PDE and ATP in the cirrhotic livers.

Adult↗
PubMed1991

Magnetic resonance imaging of macroscopic intrahepatic portal-hepatic venous shunts.

Direct communication between portal branches and the hepatic vein [macroscopic intra-hepatic portal-hepatic venous shunt (IPHVS)] is a rare entity. We have recently studied five patients with this condition. Magnetic resonance imaging (MRI) clearly demonstrated in each case the portal-hepatic venous shunt due to "flow void." Multiple diffuse shunts were present in one case and a solitary shunt was demonstrated in the others. The solitary shunt was either tubular, focally dilated or racemose in configuration. The MRI findings and clinical significance of this rare entity are discussed.

Adult↗
PubMed1990

[Fundamental evaluation of bone densitometry using dual energy X-ray absorptiometry (DEXA)].

A newly developed instrument based on dual energy X-ray absorptiometry (DEXA), Hologic QDR-1000, was evaluated fundamentally and clinically. Image quality was quite satisfactory though radiation exposure was minimal, 780.2 nC/kg (3.024 mR) for lumbar measurement. Reproducibility of the repeated measurement of a phantom was fairly good; 0.343 CV% in a same day and 0.520 CV% in a long period. Accuracy determined by measurement of potassium phosphate solution was also satisfactory. Bone mineral densities measured by this instrument were fairly correlated with those measured by single energy quantitative CT; coefficient was 0.740 for 17 patients. Mix-DP plates of more than 10 cm thick overestimated the bone mineral densities of a phantom. Bone mineral densities of Japanese normal volunteers were in the normal range (mean +/- 2SD) of the Americans though mostly lower than the mean. In patients with spondylosis deformans or prominent aortic calcification, bone mineral densities might be overestimated. Lateral view was obtainable though its reproducibility was not good. Positioning especially for measuring femoral neck was quite critical for reproducible measurement. In conclusion, this new instrument is quite accurate and satisfactory for clinical application to measuring bone mineral densities.

Absorptiometry, Photon↗
PubMed1990

Cystic cavernous hemangioma of the liver.

We report an unusual case of multilocular cystic cavernous hemangioma of the liver. The patient was a 61-year-old woman without liver disfunction but who had multicystic mass lesions in the liver. Although cavernous hemangiomas are usually accurately diagnosed by the various imaging modalities, our case showed atypical features.

Diagnosis, Differential↗
PubMed1990

Visualization of the bone/bone marrow of lower extremities in Ga-67 whole-body images.

Patients whose Ga-67 whole-body images showed increased uptake by the bone/bone marrow of the lower extremities were selected and classified into three types according to the extent and the grade of the visualization. These types were then compared with their serum iron levels, iron-binding capacities, and the results of several other serum biochemical tests. Of 374 consecutive whole body 72-hr images reviewed, 59 (15.8%) showed increased uptake of the tracer by the bone/bone marrow of the lower extremities. The three classified types were as follows: type T--visualization of both tibiae and femurs; type S--strong visualization of the femurs; and type W--weak visualization of the femurs. The serum iron concentration was significantly high in type T and low in type S. In conclusion, the pattern of Ga-67 uptake by the bone/bone marrow of the lower extremities fairly closely reflects the status of iron metabolism.

Adolescent↗
PubMed1990

[123I-iodoamphetamine single photon emission computed tomography in three patients with amyotrophic lateral sclerosis].

We examined the 123I-iodoamphetamine SPECT for 3 patients with ALS, who were clinically diagnosed. Patient 1 was a 31-years-old man, who had bilateral muscle weakness of his upper extremities, and spasticity in lower extremities. Patient 2 was a 51-years-old woman, who had marked weakness of her upper extremities and bulbar sign. Patient 3 was a 68-years-old man, who had severe degree of marked weakness of his upper extremities and mild bulbar signs. Cerebral cognitive function were all normal in three patients. Computed tomographic and magnetic resonance imagings showed moderate degree of cortical atrophy in patient 1, but no abnormalities in patients 2 and 3. In 123I-IMP SPECT, however, hypoperfusion were recognized on the bilateral fronto-parietal border zone areas in these three patients with ALS. It was suggested that patients with ALS showed varying degrees of impaired perfusion in the fronto-parietal border zone areas in spite of normal cognitive functions.

Adult↗
PubMed1989

[Hepatocellular carcinoma associated with schistosomiasis japonica; CT and angiographic features].

One-hundred and fourteen cases of hepatocellular carcinoma (HCC) which underwent computed tomography (CT) and angiography at the University Hospital of Yamanashi were reviewed. These included 24 cases of HCC associated with hepatic schistosomiasis japonica. Compared with the other cases, radiological features of HCC with schistosomiasis japonica were clarified. Patients with multinodular HCC were most common (13/24), followed by those with single nodular HCC (7/24), while those with massive or diffuse HCC were few (4/24). In patients with marked CT changes (grade III or IV) of hepatic schistosomiasis japonica, most of HCC nodules were disclosed as a mass with homogenous hypodensity surrounded by "shell-like calcifications". Obstruction of the portal vein or its branches due to tumor thrombus was rarely noted (4/24). These features are presumably attributed to periportal fibrosis which is characteristic of heptic schistosomiasis japonica. Because of these features, it is expected that hepatocellular carcinomas with schistosomiasis japonica can be treated by transcatheter arterial embolization more effectively than those without schistosomiasis japonica.

Aged↗
PubMed1989

67Ga scan for evaluating response to therapy in malignant lymphoma.

67Ga scintigrams in a patient with malignant lymphoma before and after chemotherapy are presented. 67Ga did not accumulate in the mostly necrotic mass with some viable cells. Negative uptake of 67Ga might reflect necrosis of the tumor; however, it is difficult to detect some residual tumor cells. Therefore, negative uptake of 67Ga in the mass seen in X-ray CT may not be totally reliable evidence of eradication of viable tumor cells.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Newly developed transarterial chemoembolization material: CDDP-lipiodol suspension.

Cis-Diamminedichloroplatinum (CDDP)-lipiodol suspension (CLS) was developed as a transarterial chemoembolization (TACE) material. The CLS was injected into the proper hepatic artery or distal branches of patients with hepatocellular carcinoma. Strong anticancer effects were observed. Plasma concentrations of total and filtrable CDDP following TACE were much lower than those following intravenous administration of CDDP solution. No major adverse complications were noted, presumably due to low CDDP concentrations in circulating plasma. The CLS appears to be an excellent TACE material.

Carcinoma, Hepatocellular↗
PubMed1989

[Tc-99m DTPA scintigraphic findings in patients with postoperative complications of renal transplantation].

Tc-99m DTPA scintigraphic findings in patients with postoperative complications of renal transplantation were presented. In acute tubular necrosis, excretion of the tracer was not observed though its perfusion was preserved. In acute rejection, perfusion was reversibly disturbed. In chronic rejection, perfusion was irreversibly disturbed. In renal infarction, multiple defects were observed. In renal vein thrombosis, similar pattern to acute tubular necrosis was found but RI venography was helpful. In lymphocele, perirenal photon deficiency was observed. In renal artery thrombosis, absence of the perfusion and total photon deficient were noted. Tc-99m DTPA renal scintigraphy is useful for diagnosis and follow up of the complications of transplanted kidneys.

Adolescent↗
PubMed1989

[Detectability of metastatic bone tumor by Ga-67 scintigraphy].

Ga-67 scintigrams in patients with malignant diseases sometimes reveal uptake of the tracer in the bone metastases. Detectability of Ga-67 scintigraphy for metastatic bone tumors and benign bone lesions was compared with that of Tc-99m bone scintigraphy. Countable bone metastases detected by bone scintigraphy were evaluated whether the lesion showed apparent, faint, or negative Ga-67 uptake. Of 47 lesions 23 (49%) showed apparent uptake and 17 (36%) showed negative uptake. On the other hand, of 71 benign bone lesions, only 7 (10%), mostly fracture/osteotomy, showed apparent uptake of the tracer. Uptake in the other benign lesions such as trauma of the ribs, spondylosis deformans, and arthrosis deformans was rather faint. In patients with multiple bone metastases, 9 patients (82%) out of 11 showed more prominent abnormal findings in Tc-99m MDP bone scintigraphy than in Ga-67 scintigraphy; that is, Ga-67 scintigraphy was not able to reveal all metastatic bone lesions. In patients with untreated or recurrent tumors, relation between Ga-67 uptake in the tumors and that in the bone metastases was evaluated. Of 7 patients with negative Ga-67 uptake in the primary tumors, 5 showed positive Ga-67 uptake in the bone metastases; that is, there seemed to be little relation between Ga-67 affinity to the primary tumors and that to the bone metastases. Mechanisms of the Ga-67 uptake in the bone metastases were discussed. Not only the tumor cells or tissues in the bone metastases but also bone mineral or osteoclasts might be the deposition sites of Ga-67.

Aged↗
PubMed1989

[N-isopropyl-p-[123I]iodoamphetamine early dynamic image with ring-type emission CT in cerebrovascular disease].

N-isopropyl-p-[123I]iodoamphetamine (IMP) SPECT was done in 14 patients with cerebrovascular disease. Immediately after injection of 3 mCi IMP, sequential 2 minutes SPECT images (dynamic images) were obtained for 15 minutes using a circular detector array emission tomographic system (Shimadzu SET-030W). Then standard SPECT images were obtained at 30 minutes (early images) and 5 hours (delayed images) using a rotating scintillation camera ECT system (GCA-601E, Toshiba). Two patients out of 14 studies showed discrepancy of the findings between dynamic images and early images; dynamic images revealed low uptake area though early images showed no defect. Possible mechanism of this phenomenon might be due to so called redistribution phenomenon occurred during obtaining early images. In conclusion, early dynamic images is useful in cases with slightly decreased cerebral blood flow.

Adult↗
PubMed1988

Hepatocellular carcinoma: metastatic abdominal lymph nodes identified by computed tomography.

Out of 79 consecutive cases of hepatocellular carcinoma (HCC) examined with computed tomography (CT), five patients revealed metastatic swollen abdominal lymph nodes. Involved were portal, retropancreatic, common hepatic, superior mesenteric, and paraaortic nodes. CT appeared to be an excellent modality in the diagnosis of metastatic abdominal lymph nodes of HCC.

Abdominal Neoplasms↗