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Biomedical subjects

A Komatani

Publications and source records attributed to A Komatani.

At least 19 recordsLinked to original sources
PubMed1992

Heterogeneous myocardial distribution of iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in patients with hypertrophic cardiomyopathy.

IT has been proposed that iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (123I-BMIPP) is an agent for myocardial fatty acid metabolism in animal models. The aim of the present study was to determine whether alterations in fatty acid uptake and/or utilization in patients with hypertrophic cardiomyopathy (HCM) could be detected by 123I-BMIPP. Myocardial imaging with 123I-BMIPP and thallium-201 (201Tl) was performed in 14 fasted patients. A dose of 111 MBq of 123I-BMIPP was administered intravenously at rest, and myocardial emission computed tomography was obtained 20 min and 3 h after injection. The 201Tl imaging was also performed within 1 week after the 123I-BMIPP study. The regional myocardial uptake and clearance of 123I-BMIPP and 201Tl were assessed quantitatively. The myocardial distribution of 123I-BMIPP was more heterogeneous than that of 201Tl in patients with HCM. The myocardial uptake of 123I-BMIPP was lower in the anteroseptal region of the left ventricle than in the posterolateral region (74% vs. 85%, P less than 0.001). The anteroseptal wall showed a faster clearance of 123I-BMIPP than the posterolateral wall (33% vs. 27%, P less than 0.01). Both a decreased uptake and rapid clearance of 123I-BMIPP were observed in the hypertrophied myocardium of the anteroseptal wall, where 201Tl uptake was normal or even increased. Myocardial segments with a markedly increased thickness showed a lower uptake and faster clearance of 123I-BMIPP than those with mild hypertrophy (uptake 73% vs. 82%, P less than 0.05; clearance 30% vs. 25%, P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗
PubMed1992

Prolonged lung retention of 123I-IMP in pulmonary fibrosis.

We compared radiographic findings and the retention of N-isopropyl- p[123I]-iodoamphetamine (123I-IMP) in 23 patients with pulmonary fibrosis. During the 30 minutes following a rapid injection of 55.5 MBq of 123I-IMP into the antecubital vein, the image of regional activity was stored. After this, 185 MBq of 99mTc-MAA was injected and its image was stored to determine the region of interest. The half time (T1/2) of 123I-IMP release from the lung was calculated in each pixel between 10 and 25 minutes after the injection. Chest roentgenograms were taken, and the lung field was divided into 6 portions (right upper, middle and lower, and left upper, middle and lower). A quantitative score was assigned to the radiographic finding (X-ray score). The T1/2 values in the above patients were longer than the T1/2 values in normal subjects. Prolonged T1/2 values were observed in the lung fields which had high X-ray scores. The X-ray scores and the T1/2 values in corresponding areas had a positive relation.

Amphetamines↗
PubMed1992

[Effects of sodium bicarbonate on the end-tidal CO2,PaCO2, HCO3-, PH and cerebral blood flow].

To estimate the quantitative reactivity of cerebral blood flow (CBF), the effects of sodium bicarbonate on the end-tidal CO2, arterial PaCO2, HCO3-, PH and CBF were examined. The CBF was measured by 133Xe inhalation method with ring type SPECT (HEADTOME). Activation study with sodium bicarbonate administration was performed after 30 minute of resting study, and the reactivity of each parameters was investigated. The arterial HCO3- and PH increased with similar reactivity, but PaCO2, end-tidal CO2 and CBF in the non-injured hemisphere changed with irregular reactivity. The excellent correlation between PaCO2 and end-tidal CO2 was vanished by the administration of sodium bicarbonate. The reactivity of CBF did not correlate with reactivity of PaCO2 and end-tidal CO2, but correlated with arterial HCO3- and PH. Thus the measurement of arterial HCO3- and PH may be indispensable to estimate the CBF reactivity with the administration of sodium bicarbonate.

Aged↗
PubMed1992

[Thallium-201 myocardial perfusion imaging during adenosine-induced coronary vasodilation in patients with ischemic heart disease].

201Tl myocardial perfusion imaging during adenosine infusion was performed in consecutive 55 patients with suspected coronary artery disease. Adenosine was infused intravenously at a rate of 0.14 mg/kg/min for 6 minutes and a dose of 111 MBq of 201Tl was administered in a separate vein at the end of third minute of infusion. Myocardial SPECT imaging was begun 5 minutes and 3 hours after the end of adenosine infusion. For evaluating the presence of perfusion defects, 2 short axis images at the basal and apical levels and a vertical long axis image at the mid left ventricle were used. The regions with decreased 201Tl uptake were assessed semi-quantitatively. Adenosine infusion caused a slight reduction in systolic blood pressure and an increase in heart rate. The rate pressure products increased slightly (9314 +/- 2377 vs. 10360 +/- 2148, p < 0.001). Chest pain (24%) and headache (13%) were the frequent side effects. The second-degree atrioventricular block was developed in 11 of 55 (20%) patients. All symptoms and hemodynamic changes were well tolerated and disappeared within 1 or 2 minutes after discontinuing adenosine infusion. The sensitivity and specificity for the detection of patients with coronary artery disease were 100% (31/31) and 88% (7/8), respectively. 201Tl myocardial imaging during adenosine infusion was considered to be safe and useful for evaluating the patients with ischemic heart disease.

Adenosine↗
PubMed1992

[Effect of scattering and spatial resolution on SPECT quantification values: experimental study using phantoms and clinical application].

The relative SPECT values are often inaccurate by the scattering and limited spatial resolution of single photon emission CT (SPECT). These effects were studied using phantoms and some attentions on clinical application were investigated. Using cylindrical phantom divided into six compartments filled with various radioactivities, the linear correlation between SPECT value and radioactivity, and also correlation with partial reduction of radioactivity were identified. But the SPECT value was relatively increased in proportion to the reduction of radioactivity due to the increase of scattering contribution. The SPECT value represented lower radioactivity when the cortical thickness was smaller than two times of FWHM and represented half radioactivity when the cortical thickness was equal to FWHM. Excellent correlation between SPECT value and radioactive partial volume averaging of brain with CSF was recognized using our hand made phantom simulating various degree of atrophic brain. It is very important to compare SPECT image with X-CT or MR image to avoid misreading taking the above mentioned effects due to scattering and limited spatial resolution.

Atrophy↗
PubMed1992

[Automatic system design of radioimmunoassay (RIA) laboratory in Yamagata University Hospital].

An originally designed full automatic system for radioimmunoassay (RIA) examination was developed. The system was constructed with mini computer (DOMAIN 3500, Appolo), touch panel controlled personal computer (PC-9801 VM, NEC), printout device (LASER SHOT, Canon) and well-type gamma counter (COBRA, PACKARD). The mini computer was connected with hospital host computer system (FACOM M-760, Fujitsu) to get some patient's information (name, sex, date of birth, department and out-or inpatient). This on-line connection made it possible to simplify the sample registration. Then only the patient's ID-code and examination item were required for sample registration. Sample label, worksheet, report, statistics and register file were able to be printed full automatically. Our new developed system was very useful in search of some patient's previous result.

Automation↗
PubMed1991

Functional recovery of hibernating myocardium after coronary bypass surgery: does it coincide with improvement in perfusion?

To determine the relationship between functional recovery and improvement in perfusion after coronary artery bypass graft surgery (CABG), 49 patients were studied. Radionuclide angiography was performed before, 1 month after, and 6 to 12 months after CABG to evaluate regional wall motion. Exercise thallium-201 myocardial perfusion imaging was done before and 1 month after CABG to assess regional perfusion. Preoperative asynergy was observed in 108 segments, and 74 of them showed an improvement in wall motion 1 month after CABG (segment A). Sixty-six of these segments (89%) were associated with an improvement in perfusion. Eight segments that had not improved 1 month after CABG demonstrated a delayed recovery of wall motion 6 to 12 months after CABG (segment B). However, seven of eight segments (88%) already showed an improvement in perfusion 1 month after CABG. A total of 82 segments exhibited functional recovery after CABG and were considered hibernating segments. In the preoperative study segment B more frequently had areas of akinesis or dyskinesis than segment A (75% vs 34%, p less than 0.05). The mean percent thallium-201 uptake in segment B was lower than that in segment A (74% +/- 9% vs 83% +/- 8%, p less than 0.05). Functional recovery of hibernating myocardium usually coincided with an improvement in perfusion. However, delayed functional recovery after reperfusion was observed in some instances. Severe asynergy and severe thallium-201 defects were more frequently observed in these segments with delayed recovery. Hibernating myocardium might remain stunned during those recovery periods.

Coronary Artery Bypass↗
PubMed1991

Dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging: a new marker of triple-vessel disease.

To investigate the significance and mechanism of dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging, we performed both dipyridamole thallium-201 imaging and dipyridamole radionuclide angiography on 83 patients with known angiograms. The dipyridamole/delayed ratio of the left ventricular dimension from the thallium-201 image was defined as the left ventricular dilatation ratio (LVDR). An LVDR greater than the mean + two standard deviations in patients without coronary artery disease was defined as abnormal. Twenty-two of 83 patients showed an abnormal LVDR, and 18 of the 22 patients (82%) had triple-vessel disease. By defect and washout analysis, the sensitivity and specificity for correctly identifying the patients as having triple-vessel disease was 72% and 76%, respectively, whereas LVDR had a sensitivity of 72% and a specificity of 93%. When LVDR was used in combination with the defect and washout criteria, sensitivity increased to 84% without a loss of specificity. In those 22 patients with abnormal LVDRs, end-diastolic volume measured by radionuclide angiography did not change after dipyridamole infusion. Dilatation of the left ventricular cavity on dipyridamole thallium-201 imaging reflected relative subendocardial hypoperfusion induced by dipyridamole rather than actual chamber enlargement. The LVDR was moderately sensitive and highly specific for triple-vessel disease and provided complementary information to dipyridamole thallium-201 imaging.

Adult↗
PubMed1991

[Evaluation of silent myocardial ischemia by exercise radionuclide ventriculography: comparison between patients with and without old myocardial infarction].

We evaluated left ventricular systolic function during exercise in patients with silent or symptomatic myocardial ischemia by radionuclide ventriculography (RNV). The subjects consisted of 61 patients who had evidence of myocardial ischemia during exercise RNV defined as positive exercise electrocardiographic changes and angiographically documented coronary artery disease. The patients without angina during exercise (SMI) had less exercise-induced left ventricular systolic dysfunction than patients with angina (CP) (change in ejection fraction during exercise: delta EF; -1 +/- 13 vs -6 +/- 10%, p less than 0.05, systolic blood pressure/end-systolic volume in exercise divided by systolic blood pressure/end-systolic volume in rest: SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.8 +/- 0.3, p less than 0.05). The 61 patients were divided into two groups, that is, those with and without old myocardial infarction (OMI), and we compared the degree of left ventricular systolic dysfunction during exercise between SMI and CP by RNV in each group. In patients without OMI, SMI had less exercise-induced left ventricular dysfunction than CP (delta EF; 1 +/- 12 vs -10 +/- 8%, p less than 0.01, SP/ESV (ex/rest); 1.1 +/- 0.6 vs 0.7 +/- 0.2, p less than 0.01). However, there were no differences between SMI and CP with OMI. In conclusion, it was thought that SMI without OMI was less degree of myocardial ischemia, and that SMI with OMI was potentially caused by some factors except for the degree of myocardial ischemia.

Aged↗
PubMed1991

[Simultaneous assessment of wall motion and myocardial perfusion by technetium-99m methoxy isobutyl isonitrile].

The aim of this study was to assess whether or not myocardial uptake of Technetium-99m methoxy isobutyl isonitrile (Tc-MIBI) indicated myocardial viability. We performed simultaneous Tc-MIBI angiography and myocardial SPECT at rest on 12 patients with suspected coronary artery disease. Left ventricle was divided into 3 segments, and regional wall motion was graded as normal, hypokinesis and akinesis/dyskinesis. Myocardial uptake of Tc-MIBI was assessed as normal, reduced and absent in each segment. In segments with normal and reduced Tc-MIBI uptake, 7% (2 of 28) and 33% (2 of 6) showed wall motion abnormalities of akinesis/dyskinesis, respectively. However, all segments with absent Tc-MIBI uptake had asynergy of akinesis/dyskinesis (2 of 2, 100%). Myocardial Tc-MIBI uptake at rest indicated wall motion abnormalities and was considered to be useful for the evaluation of myocardial viability. First-pass radionuclide angiography followed by myocardial SPECT with Tc-MIBI demonstrated to be useful for the simultaneous assessment of the left ventricular wall motion and myocardial perfusion.

Coronary Circulation↗
PubMed1990

[A phase III multi-center clinical trial on 123I-orthoiodohippurate (123I-OIH)].

A multi-center clinical trial was performed to evaluate the clinical usefulness of 123I-orthoiodohippurate (123I-OIH) in patients with renal and urinary disorders. 123I-OIH was evaluated to be "safe" in all 259 cases it was injected. 123I-OIH was useful in all 248 cases analyzed for the overall clinical usefulness evaluated by the investigators. The clinical significance of the drug was also evaluated in terms of renal blood flow function, renal parenchymal function, urinary function and the ability to differentiate between renal and urinary disorders. In the comparison with 123I-OIH (90 cases), 123I-OIH was superior as evaluated by the investigators and the Committee both. In the comparison with 99mTc-DTPA (113 cases), 123I-OIH was evaluated as superior by the investigators, but no significant difference was found by the Committee. In image qualities, 123I-OIH was evaluated as superior to 131I-OIH and equal to 99mTc-DTPA by the Committee. In overall efficiency, 123I-OIH was evaluated as being more valuable than 131I-OIH in 92% of the 90 cases and more valuable than 99mTc-DTPA in 50% of the 113 cases. 123I-OIH was evaluated as being less valuable than 131I-OIH in no cases and less valuable than 99mTc-DTPA in 7% of the 113 cases. These results suggest that 123I-OIH is superior to 131I-OIH and equal or superior to 99mTc-DTPA as a radiopharmaceutical for gamma camera-renography.

Clinical Trials as Topic↗
PubMed1990

[Cerebral blood flow and brain size in healthy subjects--sensitivity to age and gender].

Cerebral blood flow was measured in 56 healthy subjects who ranged in age from 1.3 to 80 years. The Xe-133 inhalation method with ring type single photon emission computed tomography (SPECT); HEADTOME was used. The cerebral blood flow were calculated by the method of Kanno & Lassen. Then the value were corrected for end-tidal CO2 concentration that had an excellent correlation with PaCO2 and was one of the most sensitive factors to change cerebral blood flow. The brain-size index was obtained by measuring the lateral and antero-posterior diameters from the SPECT images. The mean cerebral blood flow in children less than five years of age was 90-100 ml/100 g/min that was approximately twice that found in adults. The mean cerebral blood flow decreased rapidly with age until 24.0 years of age in male and 21.7 in female. Thereafter, there was a slow decrease and a negative correlation with age was found. In adults, the mean value of the cerebral blood flow of females was slightly higher than that of males (p less than 0.01). In contrast, the brain-size index of females was significantly smaller than that in males (p less than 0.01). There was a significant negative correlation to an inverse proportionality of cerebral blood flow and brain-size index (p less than 0.002). But, there was no significant correlation between total flow index that obtained to multiplied mean flow by brain-size index and brain-size index or gender.

Adolescent↗
PubMed1990

[Effect of aminophylline on thallium-201 washout rate during myocardial perfusion imaging with dipyridamole].

Thallium-201 myocardial perfusion imaging with dipyridamole was performed on 78 patients (pts) with suspected coronary artery disease (CAD). Twenty eight pts had normal coronary arteries (control group), and 50 pts had 50% or greater stenosis in one or more major coronary arteries (CAD group). In control group, aminophylline (Am) was infused intravenously on 12 pts during dipyridamole testing. Mean washout rate (WR) of these 12 pts was greater than that of 16 pts without Am (42% vs 35%, p less than 0.01). Then normal limit of WR was defined separately from the pts of control group with and without Am. The sensitivity for detecting the pts with CAD by WR analysis which normal limit was calculated separately with and without Am was 92% (46/50). When normal limit of WR was determined from all pts in control group, the sensitivity decreased to 84% (42/50). Am significantly affected thallium-201 washout during dipyridamole testing. WR of CAD pts should be estimated by specific set of normal limit with and without Am.

Aminophylline↗
PubMed1989

Relationship of thallium-201 defect and left ventricular function after dipyridamole infusion.

Tl-201 imaging and first-pass radionuclide ventriculography (RNV) by 4 min infusion of 0.56 mg/kg dipyridamole were performed on 22 patients with coronary artery disease in order to know the relationship of myocardial perfusion and left ventricular function after dipyridamole-infusion, and thereby to define whether Tl-201 defect with dipyridamole could imply myocardial ischemia. Initial and delayed Tl-201 images were divided into anterior, apical, and infero-posterior segments, and segmental perfusion defects were categorized as reversible, fixed and no defect. RNV on the 30-degree right anterior oblique view was also divided into anterior, apical, and infero-posterior wall to be evaluated for regional wall motion by a 5 point score before and after dipyridamole. Changes in left ventricular ejection fraction (LVEF) with dipyridamole were also calculated. Normal responses of regional wall motion and LVEF to dipyridamole were established from the data of 14 normal subjects. Reversible defects were closely associated (69%) with an abnormal response of regional wall motion (score decrease of 1 or more after dipyridamole). Both fixed defects and no defects showed little association with abnormal response of regional wall motion. Moreover, 77% of the patients having reversible-defect segment showed an abnormal response of LVEF (reduction of 3% or more following dipyridamole). However, patients without reversible defect did not show an abnormal response to dipyridamole. These results suggest that dipyridamole-induced Tl-201 defects represent a myocardial ischemia which causes a reduction of ventricular function.

Adult↗