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Biomedical subjects

K Hisada

Publications and source records attributed to K Hisada.

At least 127 records · Page 7Linked to original sources
PubMed1992

Application of a continuous ventricular function monitor with miniature cadmium telluride detector to patients with coronary artery bypass grafting.

A continuous ventricular function monitor with a miniature cadmium telluride detector was evaluated and applied to patients with coronary bypass surgery (CABG). Ejection fraction (EF) at rest and change in EF from rest to exercise and postexercise (Y) measured with the device correlated with that of the gamma camera (X) (Y = 0.86x + 6.8(%), r = 0.87, n = 110, p less than 0.001, and Y = 0.96x + 0.4(%), r = 0.90, n = 37, p less than 0.001 respectively). Left ventricular function during and after supine ergometer exercise was monitored in 54 patients before and after CABG. The EF change from baseline to peak exercise improved from -5.9% +/- 8.9% before CABG to 7.2% +/- 7.9% after CABG (p less than 0.001). In all patients but two, a rapid EF increase just after exercise over baseline EF was observed. This EF "overshoot" during recovery increased from 11.5% +/- 6.5% to 16.4% +/- 6.0% (p less than 0.001) after CABG. The time from the cessation of exercise to EF overshoot decreased from 153 +/- 80 sec to 76 +/- 49 sec (p less than 0.001) after CABG. The continuous ventricular function monitor with a miniature cadmium telluride detector is able to measure EF reliably. Following successful aortocoronary bypass, EF response during exercise improved and the EF overshoot in the recovery phase became faster and higher.

Cadmium↗
PubMed1991

The role of Tc-99m IDA hepatobiliary and Tc-99m colloid hepatic imaging in primary biliary cirrhosis.

To assess the presence of primary biliary cirrhosis, 15 patients at various histopathologic stages were studied by Tc-99m IDA hepatobiliary and/or Tc-99m colloid hepatic imaging. In the earlier stages (I and II), seven of eight patients (88%) showed uniform hepatic retention of Tc-99m IDA. Of seven patients in the same stage, however, four (57%) showed no abnormality on Tc-99m colliod imaging. In three of these four negative patients (75%), uniform hepatic retention of Tc-99m IDA was noted. In the later stages (III and IV), all seven patients showed decreased clearance with or without delayed tracer appearance in the intestine and prominent hepatic retention on Tc-99m IDA imaging; with Tc-99m colloid imaging there was enlargement of the spleen and increased activity in the spleen and bone marrow. Thus, Tc-99m IDA imaging is considered to be more useful in revealing this functional disorder at the earlier stage of primary biliary cirrhosis and in evaluating progression from an earlier to a later stage of disease. Tc-99m colloid imaging also effectively evaluated progression.

Bone Marrow↗
PubMed1991

Papillary carcinoma in ectopic thyroid detected by TJ-201 scintigraphy.

A 37-year-old man with papillary carcinoma in an ectopic thyroid is presented. Excisional biopsy revealed the cervical mass to be a metastasis from thyroid cancer. X-ray, ultrasonography, and computed tomography, however, failed to identify the primary tumor in the thyroid. Incidental TI-201 uptake was noted in the midline of the anterior neck, and a palpable nodule was discovered in this area. Fine needle aspiration cytology demonstrated Class V papillary adenocarcinoma, and subsequent surgery confirmed a papillary carcinoma in the ectopic thyroid. This case suggests the usefulness of TI-201 scintigraphy for the detection of ectopic thyroid malignancy.

Adenocarcinoma, Papillary↗
PubMed1991

SPECT evaluation of brain perfusion reserve by the acetazolamide test using Tc-99m HMPAO.

This report describes a new approach to the evaluation of brain perfusion reserve using Tc-99m HMPAO SPECT. Consecutive brain Tc-99m HMPAO SPECT studies before and after acetazolamide (Diamox) administration were performed within 30 minutes on 19 patients with significant vascular occlusive lesions. Thirteen patients showed decreased perfusion reserve and four patients maintained perfusion reserve in the affected vascular territories after Diamox administration, providing additional information to baseline Tc-99m HMPAO SPECT in 17 (89%) patients. Although flow augmentation post-Diamox was underestimated, possibly due to the nonproportionality of Tc-99m HMPAO activity to true blood flow, significant changes in the brain perfusion pattern were both visually and quantitatively determined using an image subtraction technique. This consecutive Tc-99m HMPAO SPECT technique seems to be of practical use for the evaluation of brain perfusion reserve and for the improvement of the sensitivity of detecting pathologic areas.

Acetazolamide↗
PubMed1991

Tc-99m HMPAO SPECT analysis of neuroleptic effects on regional brain function.

This report describes a new approach to the evaluation of neuroleptic effects on regional brain function. Using Tc-99m HMPAO SPECT imaging, consecutive brain perfusion studies before and after acute haloperidol administration were performed on three schizophrenic patients and two normal volunteers. The antipsychotic drug ameliorated the hypoactivity in the frontal lobe and suppressed the hyperactivity in the temporo-occipito-parietal lobe selectively in the dominant hemisphere in the schizophrenic patients. It did not exert a significant influence on the brain perfusion pattern in normal volunteers. This nuclear medicine technique seems to be useful for the evaluation of drug effects in psychiatric diseases.

Adult↗
PubMed1991

201Tl SPECT in the detection of mediastinal lymph node metastases from lung cancer.

201Tl SPECT was performed to detect mediastinal involvement in 80 patients with lung cancer who underwent surgery within a week after the SPECT study. Out of 29 patients with mediastinal involvement 16 (55%) were positive on the 201Tl early scan at 15 min postinjection and 22 (76%) were positive on the delayed scan at 3 h. These metastatic lymph nodes tended to be visualized much better on the delayed scan. In all patients with true positive results on the delayed scan, the mediastinal lymph nodes were plural, with a lesion of more than 14 mm in size. Seven false negative cases were found to have metastatic lesions less than 12 mm in size. Both the early and delayed scans showed false positive accumulation in six of 51 patients without mediastinal involvement (specificity 88%). Thus the overall accuracy for the delayed scan was 84%. The 201Tl delayed SPECT is thought to be a good noninvasive method for assessing mediastinal lymph node metastases from lung cancer.

Aged↗
PubMed1991

Synthesis and characterization of 99Tcm-p-halophenethyl diaminodithiol analogs.

In an effort to develop new, clinically useful 99Tcm-diaminodithiol (99Tcm-DADT) complexes for the evaluation of regional cerebral perfusion, basic diaminodithiols (DADT-TM, DADT-HM and DADT-MHM) and three diaminodithiol ligands functionalized with p-iodophenethyl (DADT-IPE), N-ethyl-p-fluorophenethyl amine (DADT-EFPE) or N-ethyl-p-iodophenethyl amine (DADT-EIPE), whose chemical structures are analogous to N-isopropyl-p-iodoamphetamine (IMP), were synthesized, labelled with 99Tcm and evaluated comparatively in experimental animals. In addition, the relationships between the chemical properties of the derivatives and their brain uptake and retention were investigated. The results were: (1) Isomeric configuration of 99Tcm-DADT complexes has an influence on uptake and retention in the rat brain. (2) In basic 99Tcm-DADT complexes, a correlation exists between initial brain uptake and lipophilicity, but in 99Tcm-DADT complexes containing a chemical structure similar to that of IMP, no correlation exists. (3) 99Tcm-DADT-IPE has relatively high uptake and long retention in the rat brain.

Animals↗
PubMed1991

Regional relationships between focal hypofixation images in 123I-IMP single photon emission computed tomography and epileptic EEG foci in interictal periods in patients with partial epilepsy.

Single photon emission computed tomographic (SPECT) brain scans with N-isopropyl-(iodine-123)-p-iodoamphetamine were performed in interictal periods in 40 patients with partial epilepsies and normal X-ray CT findings, and the regional relationships between the SPECT abnormalities and interictal epileptic EEG foci were studied. Twenty-six patients (65%) had abnormal SPECT images consisting of one or more focal hypofixation images, i.e., zones of decreased regional cerebral blood flow, while the remaining 14 patients showed normal images. Nineteen (73%) of the 26 patients showed complete or partial regional agreement between the abnormal SPECT findings and the interictal epileptic EEG foci determined from EEGs recorded repeatedly during their clinical course, while the regional relationships with the EEG foci determined from the single EEG recorded just after the SPECT scans or a short interval after the scans showed a lower rate of agreement (13 of 21 patients, 61.9%). These results confirm the utility of SPECT scans in the regional diagnosis of epileptic foci.

Adolescent↗
PubMed1991

Effect of therapy with oxygen under high pressure on regional cerebral blood flow in the interval form of carbon monoxide poisoning: observation from subtraction of technetium-99m HMPAO SPECT brain imaging.

Changes in brain images with single photon emission computed tomography (SPECT) using 99mTc hexamethylpropyleneamine oxime (HMPAO) before and after therapy with oxygen under high pressure (OHP) were measured in a 66-year-old man with the interval form of carbon monoxide (CO) poisoning by a new technique, i.e., subtraction of brain images. This study was performed 187 days after acute CO poisoning, in a state of chronic akinetic mutism that followed a lucid interval. A diffuse, but frontal-dominant, hypoperfusion pattern involving both the gray and white matter was observed in the pre-OHP SPECT image. After OHP, regional cerebral blood flow increased in both the gray and white matter and markedly increased in the frontal cortical regions. The present finding suggests that OHP is effective against the chronic state of the interval form of CO poisoning.

Aged↗
PubMed1991

Functional advantage of parenchymal-sparing surgery for early hilar lung cancer.

In a group of 27 patients with early hilar lung cancer, standard sleeve lobectomy was performed in 14 cases, standard lobectomy in 9 cases, and another 4 patients underwent parenchymal-sparing operations (2 had sleeve segmentectomy, 1 had sleeve middle lobectomy, and 1 had left second carinal resection). The changes of conventional pulmonary function tests and regional pulmonary function were compared between patients undergoing sleeve lobectomy and those undergoing parenchymal-sparing surgery. The parameters used for the conventional lung function tests were FVC, %FVC, FEV1.0, and %FEV1.0. For the evaluation of regional pulmonary function, perfusion scans using 99mTc-MAA and ventilation scans using 133Xe were performed. The decrease of FVC in the sleeve lobectomy group (n = 5) was 724 +/- 182.7 ml, whereas that in the parenchymal- sparing surgery group (n = 4) was 367.5 +/- 52.1 ml, a significant difference. Both the FEV1.0 and %FEV1.0 showed no marked changes in both groups between the preoperative and postoperative values. Perfusion and ventilation scans in the parenchymal-sparing group showed a superior result in comparison with sleeve lobectomy group. All the patients undergoing parenchymal-sparing operations survived over the long term. It was thus concluded that parenchymal-sparing surgery can be applied to carefully selected patients with tiny localized cancers.

Aged↗
PubMed1991

Assessment of right ventricular overload by a thallium-201 SPECT study in children with congenital heart disease.

Thallium-201 planar and SPECT studies were performed in 38 children with congenital heart disease using high-resolution three-headed SPECT. The 201Tl total or average right ventricular-to-left ventricular (RV/LV) count ratios were measured by summed short-axis images. In the planar study, the RV/LV systolic pressure ratio correlated with 201Tl RV/LV average count ratio (r = 0.91) better than that in the SPECT study (r = 0.78). However, in the SPECT study, patients with atrial septal defect (n = 9), ventricular septal defect (n = 13), tetralogy of Fallot and double outlet right ventricle (n = 6) showed a characteristic distribution in the plot of RV/LV pressure ratio versus 201Tl RV/LV total count ratio. A prospective study showed that the RV/LV average count ratio was a good predictor of RV/LV pressure ratio (n = 19, r = 0.91). Three-headed SPECT is useful for pediatric cardiac studies, and the overload types found in congenital heart disease seemed to be differentiated by the SPECT study.

Adolescent↗
PubMed1991

Thallium-201 SPECT depicts radiologically occult lung cancer.

A case of radiologically occult lung cancer is presented in which 201TI SPECT of the chest clearly delineated the involved area. A 66-yr-old man underwent chest screening examinations for asymptomatic smokers and presented a positive sputum cytology for lung cancer. Conventional chest x-ray, tomography of computed radiography, and a CT scan failed to locate the lesion in the lung. Thallium-201 SPECT, however, was successful in depicting the area of the involvement.

Aged↗
PubMed1991

[Cardiac response to exercise before and after coronary artery bypass grafting: evaluation by continuous ventricular function monitor].

Cardiac response to exercise was evaluated with continuous ventricular function monitor (VEST) with cadmium telluride detector. Thirty-nine patients (30 male and 9 female, aged 57 +/- 8, 23 had old myocardial infarction) were monitored with VEST during and after supine ergometer exercise before and 4 weeks after coronary artery bypass grafting (CABG). Left ventricular ejection fraction (EF) responses were classified into 4 types; type A showed EF increase greater than 5% till end of exercise, type B demonstrated initial increase followed by decrease in EF, type C revealed no significant EF change, type D showed continuous EF decrease. Before CABG, each EF response type A, B, C, and D consisted of 4, 2, 12, 21 patients respectively and after CABG each type included 18, 10, 9, 2. The EF change from rest to peak exercise (delta EF-Ex) improved from -6.4 +/- 8.8% to 5.0 +/- 7.4% (p less than 0.001) after CABG. All patients showed rapid EF increase after exercise or "EF overshoot" (EF-OS). After CABG, the EF change from rest to EF-OS (delta EF-OS) and time to EF-OS (T-OS) were improved from 9.9 +/- 5.2% to 14.9 +/- 5.3% (p less than 0.001) and 162 +/- 86 sec to 80 +/- 48 sec (p less than 0.001) respectively. Type A, B patients showed higher delta EF-OS and shorter T-OS than type C, D patients, suggesting EF overshoot was contingent upon cardiac function during exercise. After CABG, in patients with myocardial infarction, T-OS shortened but delta EF-OS showed less improvement than patients without infarction, suggesting loss of myocardium hampered EF-OS.

Aged↗
PubMed1991

[Assessment of myocardial viability by 24-hour imaging after stress thallium-201 scintigraphy].

Twenty-four-hour delayed imaging after stress thallium-201 scintigraphy was assessed for more accurate detection of viable myocardium. Thirty-two patients with coronary artery disease who showed fixed perfusion abnormality (FPA) at 3 hr imaging after stress Tl study were evaluated with 24 hr delayed imaging. Of 37 areas with FPA, 19 areas (51%) showed redistribution (RD) at 24 hr imaging. After successful coronary artery bypass grafting (n = 19) or transluminal coronary angioplasty (n = 3), stress Tl scintigraphy was performed. Of 13 areas with RD at 24 hr imaging, 12 revealed improvement of Tl uptake after revascularization. On the other hand, of 12 areas with FPA until 24 hr, 8 showed no improvement. In conclusion, conventional stress Tl-201 scintigraphy underestimates myocardial viability, and additional 24 hr imaging permits more accurate assessment of myocardial viability.

Adult↗
PubMed1991

[Clinical application of Tc-99m HMPAO labeled leukocyte imaging in inflammatory disease].

A radionuclide imaging with Tc-99m HMPAO labeled leukocyte was performed in order to determine its clinical usefulness in inflammatory disease. The mixed leukocyte isolated from 40 ml of whole blood containing 5 ml of acid citrate dextrose A and 7 ml of 6% hydroxyethyl starch was incubated with 370 MBq (10 mCi) of Tc-99m HMPAO at 37 degrees C for 30 minutes. Because the labeling efficiency of Tc-99m HMPAO labeled leukocyte was 60.2 +/- 6.3%, the procedure of washing Tc-99m, leukocyte with 5 ml of physiological saline was necessary before intravenous injection, in order to remove the unlabeled Tc-99m HMPAO. The recoveries of Tc-99m leukocyte in the blood after intravenous injection were 41.1 +/- 6.7% at 5 minutes, 33.4 +/- 2.1% at 30 minutes, and 27.2 +/- 3.4% at 2 hours after injection. Moreover, the labeled leukocyte was not stained with trypan blue. Therefore, the biological activity of the Tc-99m leukocyte was maintained as that of In-111 oxine labeled leukocyte. In the 39 patients with clinical suspicion of inflammatory disease including 15 patients with acute and chronic infectious disease where both Tc-99m leukocyte and Ga-67 citrate imagings were performed, the sensitivity, specificity and accuracy for infectious disease were 47%, 100% and 79% with Tc-99m leukocyte, and 67%, 79% and 74% with Ga-67 citrate. These results suggest that Tc-99m HMPAO labeled leukocyte imaging is promising for evaluating inflammatory disease because of the much higher specificity, the ready availability of Tc-99m HMPAO, the good image quality, and the lower radiation dose to the patient.

Gallium Radioisotopes↗
PubMed1991

[Basic evaluation of an ambulatory ventricular function monitor with a a cadmium telluride detector].

The reliability of a new ambulatory ventricular function monitor (VEST) with cadmium telluride (Cd-Te) detector was validated. No counting loss was observed under 20 kcps. In phantom study, more than 200 ml with 6 cm distance from the detector and more than 300 ml with 6-12 cm distance, underestimation of volume was observed. Ejection fraction (EF) calculated in phantom study showed close value to the true EF in 50-400 ml of end-diastolic volume. In 10 patients, 1-2 cm detector shift toward right upper, upper and left showed underestimation of EF. Good correlation of gamma camera EF (X) and VEST EF (Y) was obtained (Y = 0.96X + 3.6(%), n = 37, r = 0.93, p less than 0.001). EF change from rest values, obtained from each comparable exercise and post exercise stage by gamma camera (X) and VEST (Y), showed good correlation (Y = 0.95X + 0.8, n = 20, r = 0.85, p less than 0.001). In conclusion Cd-Te VEST was considered as a reliable EF measurement technique similar to gamma camera.

Cadmium↗
PubMed1991

[Clinical evaluation of 123I-MIBG for assessment of the sympathetic nervous system in the heart (multi-center clinical trial)].

Multi-center clinical trial of 123I-metaiodobenzylguanidine (123I-MIBG) was carried out to assess its utility as a scintigraphic imaging agent reflecting sympathetic neuronal function in cardiovascular field. Studies were performed on patients with heart diseases of three categories, myocardial infarction, angina pectoris and cardiomyopathy. Scintigraphic images, reflecting sympathetic neuronal function were obtained with 123I-MIBG from all of those categories of patients and the efficacy of the imaging was revealed in 781 (95.0%) out of 822 patients. In some patients abnormality was suggested in sympathetic neuronal function with 123I-MIBG imaging, in spite of normal findings with myocardial perfusion scintigraphy by 201TlCl. In all 981 patients studied with 123I-MIBG, there have been no severe adverse reactions, except complaints of burning on injection site of the agent or nausea, etc. from 4 patients. We conclude that 123I-MIBG imaging is one of the effective tools for diagnostic use reflecting topical sympathetic neuronal function in the heart, judging from its safety and efficacy.

3-Iodobenzylguanidine↗