Publications by authors named "H Niwayama"

To evaluate the effect of the duration of fasting on myocardial fluorine-18-fluorodeoxyglucose (FDG) uptake and distribution, 16 FDG-positron emission tomography (PET) studies were performed in 7 normal volunteers under three different conditions: glucose loading, 6 h fasting and overnight fasting. In the glucose-loaded condition, all subjects had good image quality, and myocardial metabolic rates of glucose (MRGlc) were significantly higher than those in the other two conditions. In the 6 h and overnight fasting conditions, image qualities varied according to MRGlc.

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Observed myocardial activities in static image of 13N ammonia positron emission tomography (PET) contains factors about not only myocardial blood flow but also wall motion, wall thickness and glutamine synthetase activity. Those factors may help to delineate myocardial viability in 13N ammonia static image. To assess the role of 13N ammonia static image in prediction of reversibility of regional wall motion abnormalities after revascularization, we studied 20 patients with coronary artery disease.

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A C15O2 continuous inhalation and a steady-state theory using positron emission tomography (PET) have been used to quantitate regional cerebral blood flow. We extended this method for quantitative regional myocardial blood flow (RMBF) measurement. Forty-three patients, involving 4 normal volunteers, 16 patients with coronary heart disease (CHD), 20 patients with hypertrophic cardiomyopathy (HCM), and 3 patients with dilated cardiomyopathy (DCM), were studied.

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The purpose of this study is to compare the characteristics of images obtained by positron emission tomography (PET) using 18F-fluorodeoxyglucose (FDG) in the fasted state (> 6 hours) and in the glucose-loaded state (oral 50 g glucose load). In the both condition FDG-PET were performed in 18 cases with old myocardial infarction. PET images in the fasted state were divided into 2 groups (Group A; 12 cases and Group B; 6 cases).

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