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Biomedical subjects

I Mitani

Publications and source records attributed to I Mitani.

At least 19 recordsLinked to original sources
PubMed1991

Assessment of myocardial damage in dilated-phase hypertrophic cardiomyopathy by using indium-111-antimyosin Fab myocardial scintigraphy.

For the detection of myocardial cell damage, an 111In-antimyosin Fab study was carried out on seven patients (Group A) in the dilated phase of hypertrophic cardiomyopathy, seven patients (Group B) with dilated cardiomyopathy, and eight control patients (Group C). Imaging was done 48 hr after intravenous injection of 74 MBq of 111In-antimyosin Fab. Myocardial antimyosin uptake was visually graded as 0, +1, +2 or +3. A score of +2 or +3 was considered positive. The heart/lung ratio of antimyosin uptake (antimyosin index) also was determined. Antimyosin uptake was positive in seven (100%), nine (90%) and no (0%) patients in Groups A, B, and C, respectively. The antimyosin index in Groups A and B was 2.46 +/- 0.49 and 2.04 +/- 0.24, respectively, findings were significantly higher than that in Group C (1.51 +/- 0.13) (p less than 0.01). Positive biopsy findings were noted in only two patients in Group A. Thus, antimyosin uptake was increased in dilated phase hypertrophic cardiomyopathy and dilated cardiomyopathy, which suggests ongoing necrotic changes in these patients.

Adult↗
PubMed1990

Newly developed myocardial imaging by using single photon emission computed tomography (SPECT).

Thallium myocardial imaging is a useful technique to evaluate myocardial perfusion and myocardial viability in ischemic heart disease. However, myocardial imaging using single photon emission computed tomography (SPECT) and gamma-emitting radiopharmaceuticals has been recently developed for more precise evaluation of myocardial infarction and ischemia. The present study evaluates animal experiments and the clinical applications of these new myocardial imaging techniques. Areas considered on 1) myocardial necrosis assessed using 111In-antimyosin, 2) myocardial fatty acid metabolism assessed using 123I-beta-methyl-iodophenyl pentadecanoic acid (BMIPP) and 3) myocardial sympathetic neural activity assessed using 123I-metaiodobenzyl guanidine (MIBG). Dual energy SPECT using these new agents and thallium gives precise characterization of the myocardial tissue in the infarcted and ischemic area.

3-Iodobenzylguanidine↗
PubMed1990

[Assessment of myocardial damage in cardiomyopathy using 111In-antimyosin Fab myocardial scintigraphy].

111In-antimyosin Fab (AM) myocardial scintigraphy was carried out in (A) 10 patients with idiopathic dilated cardiomyopathy, (B) 7 with dilated phase of hypertrophic cardiomyopathy and (C) 8 with normal (control) individuals. Imaging was taken 48 hours after intravenous injection of 74 MBq of AM. Myocardial uptake of AM was evaluated qualitatively and quantitatively. Positive uptake was observed in 9/10 (90%), 7/7 (100%) and 0/8 (0%) in group A, B and C, respectively. AM index (heart/lung ratio) in group A and B were 2.04 +/- 0.24 and 2.46 +/- 0.49, values significantly higher than that obtained in the control patient without cardiomyopathy (1.51 +/- 0.13) (p less than 0.01). Positive monoclonal antimyosin antibody studies were highly prevalent in dilated cardiomyopathic and dilated phase of hypertrophic cardiomyopathic patients, even in the presence of negative right ventricular biopsy. It is suggested that this method was useful for the noninvasive assessment of active myocardial damage in these patients.

Adult↗
PubMed1990

[Detection of restenosis after successful percutaneous transluminal coronary angioplasty (PTCA)--usefulness of exercise thallium scintigraphy].

We studied the efficacy of stress thallium scan in detecting restenosis after primary successful PTCA. There were 21 patients with angina pectoris and 16 patients with previous myocardial infarction. The sensitivity and the specificity of stress thallium scan in detecting restenosis were superior to those of stress electrocardiography or chest pain complained in follow-up period. In multi-vessel disease, we could assess the vessel developing restenosis more easily than stress electrocardiography. Initial thallium %UPTAKE RATIO was significantly improved after PTCA but redecreased in patients developing restenosis. In patients showing residual redistribution despite of not developing restenosis, we could judge vessel patency by gradually improving initial %UPTAKE RATIO after PTCA. Thus, stress thallium scan proved to be useful in detecting restenosis after PTCA.

Aged↗
PubMed1990

[Serial assessment of denervated but viable myocardium following acute myocardial infarction by using 123I-MIBG and 201TlCl myocardial SPECT].

123I-MIBG is taken up by sympathetic nerve ending and provides a scintigraphic image of myocardial sympathetic innervation. We investigated the scintigraphic detection of denervated but viable myocardium following acute myocardial infarction by serial 123I-MIBG and 201TlCl myocardial SPECT. Fourteen patients were studied at acute (10 +/- 2 days) and chronic stage (86 +/- 10 days). Simultaneous dual SPECT was carried out after IV administration of 111 MBq (3 mCi) of 201TlCl and 123I-MIBG. The defect size of 123I-MIBG and 201TlCl were compared visually by using Bull's eye display generated from each myocardial SPECT. In all patients, 123I-MIBG defect showed larger compared to 201T1Cl defect at acute stage, which suggest the existence of denervated but viable myocardium. Of these patients, seven showed significant improvement of both defects, though 123I-MIBG defect showed slightly larger compared to 201TlCl defect, even at chronic stage. These patients had exercise induced thallium transient defect at infarcted area. The remaining 7 patients had no improvement of both defects at chronic stage, which suggest the complete scar at infarcted area. In addition to above study, 4 patients of old myocardial infarction demonstrated larger 123I-MIBG defect compared to 201TlCl defect even at old stage, which thought to be pathogenesis of ventricular tachycardia. In conclusion, 123I-MIBG could evaluate sympathetic denervation and reinnervation noninvasively in the patients with acute myocardial infarction.

3-Iodobenzylguanidine↗
PubMed1990

[Accumulation of 111In-antimyosin antibody at the focal site of inflammation].

An p6-year-old man with anterior acute myocardial infarction was administered antimyosin antibody labeled with 74 MBq (2 mCi) 111In, and abnormal hot activity was observed in the left lung by immunoscintigraphy. 67Ga-citrate scintigraphy also showed abnormal uptake in this lesion. At this time, this patient complained of fever and cough with sputum, and roentgenography showed a coin lesion-like shadow at the same location of the lung. By treatment with antibiotics, his symptom was improved and coin lesion-like shadow disappeared. So we thought the RI uptake area in the left lung was inflammatory lesion. This case suggests that 111In-antimyosin antibody can be trapped to the focal site of inflammation.

Aged↗
PubMed1990

[Clinical variables that can cause the underestimation of the viable myocardium in the infarcted area: results of the sequential exercise thallium-201 myocardial scintigraphy].

Clinical variables that can cause the underestimation of the viable myocardium were examined in the sequential exercise thallium-201 study before and after PTCA. Among 60 patients who had documented myocardial infarction with single coronary artery disease, 43 patients had successful PTCA. Compared to the initial images after PTCA, the 4 hour-delayed images before PTCA had larger and more severe defect in the infarcted area of 14 patients (33%). This underestimated group had shorter period from the infarction to the stress study. (3.4 +/- 2.4 M vs. 7.1 +/- 9.2 M; p less than 0.05), and attained more maximal heart rate during the stress study. The numbers of the patients who had severe stenosis (greater than or equal to 99%) were more in the underestimated group (79% vs. 34%; p less than 0.01). The patients who have recent myocardial infarction, especially within three months, are likely to be underestimated their viable myocardium in the infarcted area, and this variable is dependent from their workload during the stress study and the severity of the stenotic lesion which also affect the estimation of the myocardial viability.

Angioplasty, Balloon, Coronary↗
PubMed1990

[Follow-up pulmonary perfusion scintigraphy pulmonary arterial embolization in two cases of familial pulmonary arteriovenous fistula].

Follow-up pulmonary perfusion scintigraphy in evaluating pulmonary arterial embolization were assessed by two cases of pulmonary familial arteriovenous fistula. Pulmonary arteriovenous fistula was found for brain abscess in the older brother, and for dyspnea on effort in the younger brother. Pulmonary arterial embolizations were performed. (older brother: 4 times, younger brother: 5 times) Before embolization, pulmonary perfusion scintigram showed pale defect, clear asymmetric perfusion between right and left lung, and clear renal visualization. On the other hand, after the embolization, clear multiple defects agreed with the sites of embolization, and asymmetric pulmonary perfusion and renal visualization disappeared. We conclude that follow-up pulmonary perfusion scintigraphy is useful to evaluate in pulmonary arteriovenous fistula after embolization.

Adolescent↗
PubMed1989

[Scintigraphic assessment of patients with pulmonary thromboembolism by extent of perfusion defect and right ventricular function].

In 36 cases, severity of pulmonary thromboembolism (PTE) were determined with extent of perfusion defect (%PD) from pulmonary perfusion scintigraphy combined right ventricular ejection fraction (RVEF) from radionuclide angiocardiography. In 27 cases, follow-up scintigraphy was also done. After medical therapy, delta PD (= initial %PD-follow up %PD) was significant improved in patients with normal RVEF (greater than 38%) (19.40 +/- 15.58%: n = 15) than that in those with reduced RVEF (less than or equal to 38%) (0.00 +/- 3.9%). In follow-up studies, patients with larger %PD (greater than or equal to 40) showed poor prognosis than those with moderate or less %PD (less than 40). In conclusion, these both non-invasive indicators were proved to be useful for the evaluation not only the clinical severity but the prognosis of pulmonary thromboembolism.

Female↗
PubMed1989

[Assessment of cerebral blood flow in intracerebral hematoma using IMP-SPECT].

To evaluate cerebral blood flow in intracerebral hemorrhage, we performed single photon emission computed tomography using N-isopropyl [I-123] p-iodoamphetamine (IMP-SPECT) in 20 patients. IMP-SPECT was carried out using rotating gamma camera at 30 min, and 4 hrs after injection. The results were compared with those by computed tomography (CT). In all cases, the extent of hematoma by IMP-SPECT was larger than that of CT. All cases were divided into 3 groups according to the extent of peripheral area zone of hematoma by IMP-SPECT. There were 10 cases with initial hypoperfusion and complete redistribution (Group I), 6 with initial perfusion defect and complete redistribution (Group II), 4 with initial perfusion defect and incomplete redistribution (Group III). Group III had extensive hematoma compared to Group I. The extent of peripheral area zone of hematoma could be considered as the decreased blood flow area by increased intracerebral pressure and the amplitude of redistribution may be correlated with celler damage. In conclusion, IMP-SPECT was useful to asses the viability of peripheral zone of hematoma.

Adult↗
PubMed1989

[Detection of multivessel disease in patients with myocardial infarct using exercise myocardial scintigraphy--usefulness of SPECT with qualitative and quantitative analysis].

The detection of multivessel disease (MVD) in patients with myocardial infarction (MI) was performed using exercise myocardial scintigraphy with qualitative and quantitative analysis, to compare the diagnostic ability of planar (PL), planar + washout rate (PL + WR), SPECT, Bull's eye + WR (BE + WR) and SPECT + BE + WR. Forty seven patients of anterior MI (SVD: DVD: TVD = 29: 8: 10) and thirty four patients of infero-posterior MI (SVD: DVD: TVD = 16: 8: 10) were reviewed. SPECT was superior to PL to detect ischemia of RCA in patients with anterior MI (50% vs. 100%) and to detect ischemia of diagonal branch in patients with infero-posterior MI (0% vs. 83%). The detection of ischemia of LCX in patients with anterior MI revealed low sensitivity in both PL and SPECT. SPECT + BE + WR showed the highest diagnostic ability to detect MVD in patients with both anterior (87%) and infero-posterior MI (82%). We conclude that SPECT with qualitative and quantitative analysis is the most useful to detect MVD in patients with MI.

Adult↗
PubMed1989

[A case of myocardial infarction with ventricular tachycardia, which had discrepancy of defect size between 123I-MIBG and 201TlCl myocardial imaging].

123I-MIBG and 201TaCl myocardial imaging were carried out in 69 years-old man who had anterior myocardial infarction with ventricular tachycardia. In planar and SPECT imaging, the defect size of 123I-MIBG was larger compared to that of 201TlCl. The zone of fractionated activity was corresponded with the defect of 123I-MIBG. Thus, the denervated but viable myocardium could be detected by 123I-MIBG and 201TlCl myocardial imaging. 123I-MIBG may give a useful clinical information, since denervation may play a role in causing ventricular arrhythmia after myocardial infarction.

3-Iodobenzylguanidine↗
PubMed1989

[Comparison of thallium perfusion and electrocardiographic findings at exercise thallium-201 scintigraphy with coronary arteriographic findings].

Findings of thallium-201 perfusion (Tl) and exercise electrocardiography (ECG) at exercise thallium-201 scintigraphy was compared with coronary arteriographic findings (CAG) in 283 patients. We classified these cases into four groups by Tl and ECG; [A] Tl(+).ECG(+), [B] Tl(+).ECG(-), [C] Tl(-).ECG(+), [D] Tl(-).ECG(-). Redistribution of thallium-201 was evaluated by qualitative (visual) analysis. Three percent of group A consisted of the patients with normal coronary artery, and thirty-eight percent of group D consisted of the patients with coronary artery disease. On exercise thallium-201 scintigraphic imagings, most of patients with normal coronary artery showed redistribution of inferior (24%) and septum (45%). On exercise electrocardiographic findings, most of patients with normal coronary artery showed ST-segment depression in II, III, aVF, V5 and V6. In patients with coronary artery disease, single vessel disease in group B was larger than that in group C (62% vs. 33%, p less than 0.05), and triple vessel disease and left main truncus disease in group C was larger than that in group B (37% vs. 10%, p less than 0.05). On exercise thallium-201 scintigraphic imagings, most of false negative in patients with coronary artery disease changed to true positive by quantitative analysis. The patients with less than 90% coronary stenosis in group C was larger than that in group B (65% vs. 100%).

Aged↗
PubMed1989

[Pericardial fibrosarcoma demonstrated by Ga-67 scintigraphy].

A case of malignant fibrosarcoma originated from pericardium was reported. A 31 year-old female who complained of general fatigue and back pain showed dilated cardiac shadow in chest X-ray. Cardiac blood pool scan with 99mTc-RBC revealed avascular mass in pericardial cavity which push the heart up and left side. It was suspected to be malignant, since the mass had increased 67Ga uptake. CT and MRI also demonstrated that the tissue characterization of the pericardial mass was irregular, and the mass compressed venous return. The large mass originated from pericardium caused the right sided cardiac failure. In 12 years ago, she had a history of operation which resected benign hemangioma in the same space (pericardium). We could suspect the malignant transformation between the two rare pericardial tumors; benign hemangioma and malignant fibrosarcoma.

Adult↗
PubMed1989

[Usefulness of coronary angioplasty (PTCA) of the infarct-related artery in patients with prior myocardial infarction--follow up of infarct zone pre- and post-angioplasty by stress thallium scan].

We studied the efficacy of coronary angioplasty (PTCA) of the infarct-related artery in 29 patients with prior myocardial infarction by stress thallium scan. Twenty-seven patients had anterior myocardial infarction (single LAD disease), one had inferior (single RCA disease) and one had posterior (single LCX disease). According to the stress-redistribution thallium scintigraphic finding before PTCA, the patients were classified in 4 groups; (A): three patients with complete redistribution. (B): fourteen patients with incomplete redistribution. (C): seven patients with partial redistribution. (D): five patients with no redistribution. After PTCA, the parameters of residual ischemia in the infarct area (% RD and Thallium ischemic score = TIS) were improved significantly but those of infarct size (RD% uptake and Defect Score = DS) were improved slightly in group A. In group B and C, % RD, TIS, RD% uptake and DS were all improved significantly. In group D, TIS was improved slightly and DS was improved slowly 3 months after PTCA. Group A had high probability of viable muscle and group D had high probability of scar at the infarct zone. Group B and C showed intermediate type between group A and D. The change of infarct area after PTCA was variable in 4 groups but both residual ischemia and infarct size decreased in all groups. Thus, PTCA of infarct-related coronary artery is useful even in the patients with prior myocardial infarction.

Adult↗
PubMed1989

[Assessment of myocardial necrosis by 111In-antimyosin F ab scintigraphy].

111In-antimyosin F ab (AM) myocardial scintigraphy was carried out in (A) 13 patients with acute myocardial infarction (9.9 +/- 2.2 days from the onset) and (B) 9 with myocarditis and/or dilated cardiomyopathy. Forty eight hours after injection of AM, the patients were injected with 74 MBq (2 mCi) of thallium-201 (TL). The two sets of Planar and SPECT image were obtained simultaneously using dual energy window sets. In group A, positive focal AM uptake was demonstrated in 12 (92%) patients. Higher AM uptake was observed in patients who had PTCR/PTCA. By combination with TL, it is useful to detect inferior infarction and to differentiate old from acute infarction. Dual SPECT images gave precise information about the infarcted area. In group B, positive diffuse AM uptake was demonstrated in 7 (77%) patients. In conclusion, AM myocardial scintigraphy was proven to be useful for the assessment of acute necrosis after myocardial infarction but also on-going necrosis of myocarditis and/or myopathy.

Adult↗