Fundamental examination for liver function parameter LU15 by99mTc-GSA was done using the phantom. The total injected dose was measured by calculating the difference of99mTcO4-radioactivity in the syringe before and after injection. As for the liver phantom in which the radiotracer and water were poured, attaching the empty body phantom to the liver phantom and filling the body phantom with water, we respectively measured the radioactivity count per minute (cpm) and calculated the uptake ratio (cpm/total injected dose) . In this study, it is supposed that LU15 will not exceed 46.4%. We investigated LU15 of 7 normal liver function cases. It ranged 24.7% to 37.0% (mean±SD: 31.4±4.2%), and supported the phantom study. Errors from the nuclear instruments and technique of measurement were little.
Some consumer products contain small amounts of radioisotopes, which called radioactive consumer products. The benefit of the radioactive consumer products must greatly exceed the risk of radiation from them. Moreover they have to be safe for public even after disposal. In this study, we have evaluated safety of an optical microscope that contains radioactivities in its prisms and an objective lens. Aγ-ray analysis of the prism using pureGe-multichannel analyzer reveals that there exist radioactivities of thorium series in it at concentration of 7.6% by the weight. Radioluminographic images of them were taken by FLA-2000 using an imaging plate. The results showed that thorium series were contained uniformly in the glasses. Dose equivalent rates at the surface and at the point of 1 m from the head of this microscope were measured by film badges (FB) and pocket dosimeters, respectively. If we used them 240 hours (=1h×20 days×12months), the result of FB showed under detection limit (0.1mSv) .However, dose equivalent rate at 1 m led about 420μSvper year after subtracting natural radiation if we stayed just there for one year (=24h ×365day) . Although the outcomes of these evaluations of radiation exposure had little problems under the normal conditions, users had a right of determination to use or not to use these radioactive consumer products. So manufacturers have to express their products as radioactive consumer products.
Sensitivity, measurement efficiency and dynamic range of commercial imaging plates for13N, 239Puand14Cwere studied. Radioactive spots were prepared by the blotting of 0.01mlradionuclide solution on paper filters, and exposed to imaging plates (BAS3002, Fuji Photo, Co. Ltd.) for 9.5minin13Nand for 20hin239Puand14C.Minimum detection limits, a radioactivity at which the spot on the paper filter was clearly visible on the image analyzer display, were 4.5×10-2, 1.1×10-1, and 2.8×10-1Bq·h/mm2for13N, 239Puand14C, respectively. Maximum detection limit, radioactivity at which the saturation of counting was observed, were 3.6×101, 3.1×102 and 1.0×103Bq·h/mm2for13N, 239Puand14C, respectively. Therefore, the dynamic ranges were calculated to be 7.9×102, 2.8×103, and 3.6×103for13N, 239Puand14C, respectively. In conclusion, the commercial imaging plates for radioluminography have high sensitivity and practically wide dynamic range not only for14Cbut also for239Puand13N.