Scattering of gaseous125I from a bottle containing Na125I solution for iodination has been measured by distributing active charcoal granule at various heights on the inner surface of a plastic cylinder surrounding the bottle and counting the activities of granule samples. The result shows that about 70% of total scattered125I exist below the level of mouth of the bottle. By drawing the air from the bottle of the cylinder through a tube filled with active charcoal, about 90% of scattered125I collected.
Circumferential profile analysis is one of quantitative analyses in201Tl myocardial scintigraphy. We compared the detectability of coronary artery stenosis between 4 various methods of circumferential profiles (peak point method, all points method, 3 points around the peak method and average method) based on short-axial images of201Tl myocardial single photon emission computed tomography. Diagnostic criteria for coronary artery stenosis was that the circumferential profile curve of a patient was below the normal limit (mean—2SD) obtained from 23 normal volunteers in more than serial 3 profiles. After examining 16 patients with coronary artery stenosis demonstrated by coronary arteriography, it was concluded that both peak point method and 3 points around the peak method surpassed other methods in the detectability of clinically significant coronary artery stenosis.