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T Kumazaki

Publications and source records attributed to T Kumazaki.

At least 127 records · Page 7Linked to original sources
PubMed1996

[ECG-gated dual-isotope myocardial SPECT with 201Tl and 99mTc-tetrofosmin: simultaneous assessment of stress/rest myocardial perfusion and left ventricular function].

ECG-gated dual-isotope acquisition protocol involving rest imaging with 201Tl and stress 99mTc-tetrofosmin (TF) SPECT was designed for the simultaneous assessment of rest/stress myocardial perfusion and rest ventricular systolic function. This study assessed the feasibility and diagnostic accuracy of this protocol. Forty-five patients underwent the dual-isotope SPECT protocol. Twenty minutes after resting injection of 111 MBq of 201Tl, 370 MBq of 99mTc-TF was administered at a peak exercise. The dual-isotope gated SPECT acquisition was performed 1 hour later. Then, the regional count increase rate (%WT) of 99mTc-TF from end-diastole end-systole was calculated using an automated method which was developed for quantification of regional wall thickening based on circumferential profile analysis in our laboratory. Myocardial perfusion and contractility analysis was carried out using 8 segments of left ventricle with comparison of coronary angiographical findings. The sensitivity and specificity for the detection of diseased coronary vessels (> = or 75% stenosis) were 76% and 94%, respectively. Infarcted regions showing reversible defect had significantly greater %WT as compared with those with fixed defects (63 seg; 12.7 +/- 6.1% vs. 36 seg; 8.9 +/- 7.2%, p < 0.01). In conclusion, this dual-isotope protocol has some advantages; i.e., shortening an examination time, having the exact registration of stress/rest perfusion, and simultaneous evaluation of resting regional wall thickening.

Coronary Angiography↗
PubMed1995

The C-terminal region, Arg201-Gln209, of glutathione S-transferase P contributes to stability of the active-site conformation.

The C-terminal region of rat glutathione S-transferase P (GST-P) was deleted by either carboxypeptidase (CPase) A and B or site-specific truncation to evaluate the role of the region in the catalytic mechanism. The C-terminal sequence from the 201st to 209th amino-acid residues is Arg-Pro-Ile-Asn-Gly-Asn-Gly-Lys-Gln. When seven of the C-terminal amino-acid residues from the C-terminus were removed by the CPases, the catalytic activity decreased in parallel with the amino-acid removal, amounting to less than 5% of that of the wild-type GST-P. On the other hand, a decrease of the catalytic activity was observed in a different manner when the C-terminal sequence was site-specifically truncated. The VmaxGSH/KmGSH values of the mutants withthree (GSTd207-209), four (GSTd206-209) and seven (GSTd203-209) C-terminal amino-acid residues deleted, were comparable or similar to that of the wild-type GST-P, whereas those of five (GSTd205-209), six (GSTd204-209), and eight (GSTd202-209) amino-acid residue-truncated mutants decreased to 43%, 40%, and 19% of that of the wild-type GST-P, respectively. Similar results were obtained as for VmaxCDNB/KmCDNB. The nine amino-acid residue-truncated mutant showed no catalytic activity. Heat treatment at 50 degrees C for 5 min had little effect on the catalytic activities of the wild-type GST-P and GSTd204-209, whereas those of GSTd207-209, GSTd206-209, GSTd203-209 and GSTd202-209 decreased to 22%, 27%, 18% and 10%, respectively, compared to the catalytic activity of the non-treated enzymes. Considering these results, it is concluded that the C-terminal region, Arg201-Gln209, has an important role in stabilizing the active-site conformation.

Amino Acid Sequence↗
PubMed1995

Case report: inflammatory abdominal aortic aneurysm--dynamic Gd-DTPA enhanced magnetic resonance imaging features.

Inflammatory abdominal aortic aneurysm is an uncommon disorder characterized by marked thickening and extensive inflammatory changes of the aneurysmal wall. The appearances of an inflammatory abdominal aortic aneurysm on dynamic Gd-DTPA enhanced magnetic resonance imaging are described and the value of this modality in achieving a pre-operative diagnosis is emphasized.

Aged↗
PubMed1995

[Transjugular intrahepatic portosystemic shunt for upper gastrointestinal bleeding due to portal hypertension: 2-year results].

We performed transjugular intrahepatic portosystemic shunt (TIPS) in 25 patients with liver cirrhosis who developed upper gastrointestinal bleeding due to portal hypertension. The procedure was successful in 23 patients, in whom portal pressure decreased by 51%. Bleeding was stopped in all 5 emergency for whom other treatments, including sclerotherapy, had failed. During the follow-up period (mean: 367 days), shunt dysfunction due to stenosis was observed in 75% of the patients. However, by percutaneous transluminal angioplasty, the patency could be maintained in 85% of the cases after 1 year and 73% of the cases after 2 years. Re-bleeding was observed in 13% of the cases after both 1 and 2 years. Color Doppler ultrasonography was useful for detecting shunt dysfunction. TIPS seems to be an effective treatment of upper gastrointestinal bleeding due to portal hypertension.

Adult↗
PubMed1995

[CT analysis of aortic cobwebs in aortic dissection].

Contrast-enhanced CT images in patients with acute or chronic aortic dissection were evaluated for the purpose of determining the clinical usefulness of "aortic cobwebs", which were originally reported by Williams et al. as an anatomical marker of the false lumen. Aortic cobwebs were detected in 13 of 44 cases (30%), demonstrating as low density structures in the false lumen continuing from the intimal flap. The aortic cobwebs were mainly linear in shape, and the size ranged from 5 x 1 to 15 x 3 mm (mean: 9 x 2 mm). Aortic cobwebs were more frequently demonstrated in chronic than in acute cases, and were more often detected in the abdominal aorta. Follow-up CT examinations of the cobwebs revealed no interval change in six cases, disappearance in three cases and thickening in one case. There was no significant correlation between the sequential changes in the cobwebs and dilatation or thrombus formation in the false lumen. Aortic cobwebs seem to represent partially residual bands of the aortic media incompletely sheared from the aortic wall during the initial processes of aortic dissection. These structures are considered to be a reliable anatomic marker and to be useful for CT identification of the false lumen in aortic dissection.

Adult↗
PubMed1995

[Superselective local infusion therapy with tissue-plasminogen activator for acute massive pulmonary thromboembolism: preliminary clinical experience].

Three cases of acute massive pulmonary thromboembolism were treated with the superselective infusion of tissue-plasminogen activator. Superselective pulmonary angiography immediately after administration of tissue-plasminogen activator demonstrated angiographic improvement in all patients. No complications were encountered during or after the procedure. It is considered that superselective infusion of tissue-plasminogen activator can be an effective therapy for massive pulmonary thromboembolism.

Acute Disease↗
PubMed1995

[Contrast enhancement and morphological findings of hematopoietic regions of bone marrow on MR imaging: comparative study with spondylitis and vertebral tumors].

The enhanced MR findings of hematopoietic regions in aplastic anemia were compared with those of spondylitis, metastatic vertebral tumors and hematologic neoplasms. The enhanced MR images showed hematopoietic regions to homogeneously enhance and occupy the margin of vertebral bodies, while spondylitis and metastatic tumors appeared as round, inhomogeneously enhancing lesions. MR images of leukemia and myelodysplastic syndrome showed homogeneous enhancement at the margins of vertebrae that was difficult to differentiate from hematopoietic regions. Enhanced MR images were useful in detecting the hematopoietic areas in marrow and differentiating them from spondylitis and metastatic tumors, although further experience is needed to distinguish between tumorous hyperplastic regions and benign hematopoietic regions in marrow.

Adult↗
PubMed1995

[MR angiography of the venous system of lower extremities with gadolinium-enhanced fast spoiled GRASS].

MR angiography (MRA) of the venous system of the lower extremities was carried out in 10 patients with varicose veins using the Gd-DTPA-enhanced Fast Spoiled GRASS (FSPGR) method. The quality of imaging of the popliteal vein (n = 20), calf deep vein (n = 20), varicose vein (n = 12), and femoral vein (n = 6) were assessed in terms of four categories: excellent, good, marginally adequate and nondiagnostic. Nineteen popliteal veins, seventeen calf deep veins, and nine varicose veins were judged as excellent or good. All femoral veins were evaluated as excellent. Enhanced FSPGR was useful for the preoperative evaluation of patients with varicose veins.

Femoral Vein↗
PubMed1995

[ECG-gated dual isotope myocardial SPECT with 99mTc-MIBI and 123I-BMIPP in patients with ischemic heart disease].

Simultaneous dual-isotope SPECT with 99mTc-methoxy isobutyl isonitrile (MIBI) and 123I-beta-methyl iodophenyl-pentadecanoic acid (BMIPP) was performed in 25 patients with ischemic heart disease. ECG-gated myocardial SPECT was acquired following the injection of MIBI (555 MBq) and BMIPP (148 MBq). Both MIBI and BMIPP scans provided high-quality myocardial images. Then, myocardial count increase rate (%WT = ES-ED/ED x 100) was calculated as an index of left ventricular contraction using MIBI gated SPECT data. The %WT was well correlated with severity scores of both MIBI image (r = -0.70) and BMIPP image (r = -0.72). Thus, ECG-gated dual-isotope SPECT with MIBI and BMIPP was considered to be useful method for assessment of left ventricular contraction as well as myocardial perfusion and fatty acid metabolism.

Aged↗
PubMed1995

[A study of the simultaneous acquisition of dual energy SPECT with 99mTc and 123I: evaluation of optimal window setting with myocardial phantom].

To examine crosstalks (CRs) between 99mTc-methoxyisobutyl isonitrile (MIBI) and beta-methyl-p-(123I)iodophenyl-pentadecanoic acid (BMIPP), myocardial phantom studies of simultaneous acquisition were performed with three window widths and four energies where the window located. CRS in 99mTc window were less than 10.5% regardless of the window settings. CRs in 123I window were ranging from 17.0% to 8.6% depending on the window setting. There were significant correlations between the isotope concentration and counts of 99mTc and 123I, respectively (r = 0.98, p < 0.0001). We concluded that the optimal window setting of 99mTc-MIBI and 123I-BMIPP (10% width, 140 keV center 99mTc window and 10% width, 164 keV center 123I window) yields good quality images in dual isotope SPECT.

Aged↗
PubMed1995

[Low-dose dobutamine stress test for the evaluation of cardiac function using ECG-gated SPECT scintigraphy with 99mTc-MIBI].

Although 201TlCl myocardial scintigraphy has so far been widely used for the evaluation of the viability of the myocardial infarcted area, functional evaluation using low dose dobutamine (DOB) loaded echography also became recently available. We performed 99mTc-mIBI gated SPECT on eight cases of myocardial infarction at rest and low dose (4-6 micrograms/kg/min) DOB-loading and related data were collected. Next, we calculated myocardial count increase rate (% WT = ES-ED/ED x 100) with left ventricular contraction from end-diastolic (ED) and end-systolic (ES) pictures in short-axial image, and made a comparative examination of regional contractilities at rest and DOB-loading. DOB-loaded echography performed on the same cases at the same dose revealed 15 segments as infarcted area (WM (+)) presenting improvement in wall movement at loading and 5 segments as infarcted area (WM (-)) presenting no such improvement, and %WT at rest and loading were 29.1 +/- 6.2 and 33.2 +/- 2.4 for (WM (-)) and 26.8 +/- 9.8 and 40.0 +/- 12.3 for (WM (+)), indicating a significant increase (p < 0.05) at loading. Contractility analysis using MIBI gated SPECT in combined use of DOB-loading was considered as a useful method of examination in view of its reflectability in the evaluation of the wall movement in DOB-loaded echography and of its high quantitativity.

Aged↗
PubMed1995

[Usefulness of the 201TlCl exercise leg perfusion scintigraphy inarteriosclerosis obliterans (ASO)--with evaluation of leg perfusion comparing before and after PTA].

Twenty-eight patients of arteriosclerosis obliterans (ASO) complaining of intermittent claudication or pain at rest underwent symptom limited exercise leg perfusion scintigraphy using 201TlCl (Tl). Regions of interest (ROI) were drawn around each buttocks, thighs, calves and feet in whole body image, and we calculated Lesion/Normal Index (LNI) which was the divided value of the average count per pixel of each ROI of the affected side by that of the normal side. The average LNI of the foot was 0.81 and was smaller than other regions (p < 0.05). Other region except foot showed Tl high uptake in affected side in some cases. Fifteen patients were compared after percutaneous transluminal angioplasty (PTA) with before PTA, and LNI of the foot was statistically improve after PTA (p < 0.005). The period suffer from disease of the group of Tl high uptake in the affected leg was statistically shorter than that of the group of Tl non-high uptake (p < 0.05). We supposed that the Tl uptake of the foot reflects ischemia of the leg sensitively, and high uptake of Tl in affected leg is concerned with compensatory change of microcirculation of ischemic leg in subacute period. This scintigraphy was thought to be useful to detect the ASO and to evaluate the effect of PTA, and was able to avail diagnosis and observation of the course of ASO patient.

Adult↗
PubMed1995

[Early diagnosis of pancreatic carcinoma and utility of helical CT].

The pancreatic carcinoma, what is one of difficult carcinomas to treat. It is because the pancreatic carcinoma does infiltrate to external at early stage. However, it leads to increase of operation with significance to check it at early stage. Helical CT is developed in late years, and spread rapidly. This examination includes many clinical utilities. In early diagnosis of pancreatic carcinoma, improve former problems, and is thought that utility is high.

Humans↗
PubMed1995

[Late phase contrast enhanced-CT analysis of thrombosed type aortic dissection].

Seven patients with thrombosed type aortic dissection who underwent both early- and late-phase contrast enhanced (CE)-CT scans were analyzed. The image acquisition of early-phase CE-CT began 30 seconds after the intravenous administration of contrast material at an injection rate of 1.5 ml per second. Late-phase CE-CT began 6 minutes after contrast material injection. The thrombosed false lumens were not enhanced on early-phase CE-CTs in any of the cases. In five of seven cases, on the other hand, false lumens of the descending aorta were enhanced on late-phase images. Late enhancement in the false lumen was roughly divided into two patterns; (1) a crescentic enhancement of the sub-adventitial region (3 cases), and (2) a vague enhancement around the ulcerlike projection (2 cases). The mechanism of late enhancement in the false lumen was not fully elucidated. Although the clinical significance of late enhancement has not yet been established, it will be useful to demonstrate an unstable status of the thrombosed false lumens before organization.

Aged↗
PubMed1995

[Hepato-biliary excretion of water-soluble iodinated contrast medium shortly after abdominal angiography].

Thirty-nine patients underwent CT examination 15 to 30 min after abdominal angiography with ioxaglate. Gallbladder opacification was observed in 15 patients in the absence of clinical evidence of renal impairment. Among them, 14 patients revealed liver cirrhosis or chronic hepatitis, and one patient showed severe fatty liver on CT. The amount of contrast medium used varied from 70 ml to 310 ml (mean 180 ml). There was no significant relationship between visualization of the gallbladder and the total dose of ioxaglate or presence of liver dysfunction, which indicated that gallbladder opacification was not a rare phenomenon on CT shortly after abdominal angiography with a normal dose of ioxaglate. Gallbladder opacification on CT examination shortly after abdominal angiography shows that the hepatobiliary tract is important in the excretion of ioxaglate.

Abdomen↗
PubMed1994

[Stent placement without thrombolysis in chronic iliac arterial occlusion: preliminary clinical evaluation].

Intra-arterial stent placement without thrombolytic therapy was performed in four patients with chronic iliac arterial occlusion. The length of angiographically observed occluded lesions ranged from 2.0 cm to 14.0 cm (mean: 5.1 cm). The implanted stents included four Wall stents, two Strecker stents and one Palmaz stent. The mean ankle-arm index before and after stenting improved from 0.48 to 0.77, while the mean pressure gradient improved from 82.5 mmHg to 3.0 mmHg. Symptoms were eliminated in all patients after the procedure. No major complications were encountered during the procedure. Primary stent implantation in chronic iliac occlusions is useful to avoid bypass surgery.

Aged↗