A new technique of phosphor screen imaging has been proposed. The floating radioluminography can be approached by exposing the imaging plate (IP) without bringing into contact with a radioactive sample. Thus, since it can be free from the radioactive contamination, we can employ the3H-IP repeatedly. Moreover, when the exposure to the IP is held in a vacuum, the detection sensitivity can be greatly enhanced.
Rice plant samples were grown in 14 cultivative pots under six different pH conditions of acid irrigation water (pH: 6.5, 6.0, 4.5, 3.5, 3.0, 2.5) and ion exchange water (pH: 7.5), in order to study an influence of pH of irrigation water on the tranfer of elements into rice plant from soils. The acid irrigation water was prepared by adding mixed solution of 1 N H2SO4and 1N HNO3 (1: 1) to ion exchange water. The rice grain yielded was separated into three parts, i.e., polished rice, bran and chaff, and they were powdered one by one. The contents of twenty five elements in the three parts of grain (14 samples each) were determined by a neutron activation analysis. It was clarified that the contents of Cu, Zn, Fe, Cr, Mg, Rb, Mo, Ni, and Cs in the polished rice increased with decreasing pH of the acid irrigation water. The contents of Se and Br, on the contrary, decreased. Significant changes of the contents were not observed for Na, AI, Sc, Mn, Cl, Ca, V and Co. The relationships between the contents of elements in the bran or chaff and pH of the acid irrigation water were not so clear as the case of bolished rice. The enrichment factor of trace elements from soils was calculated for the polished rice, bran and chaff The high enrichment of Cl, Mo, Zn, Se and Cu was observed in the polished rice. Manganese and Cr were concentrated more in the bran than in the polished rice.
Accumulation of99mTc-MIBI has been reported in several various carcinomas. In this study, 99mTc-MIBI scintigraphy was evaluated to detect recurrent or metastatic lesion in seven patients with thyroid carcinoma. The results were compared with those of131I scintigraphy and201T1 scintigraphy. Bone metastasis and lymphnode metastasis were well demonstrated in99mTc-MIBI scintigraphy, but131I scintigraphy allows the best visualization of pulmonary metastasis. 99mTc-MIBI scintigraphy has desirable characteristics including the potential for no thyroid hormone withdrawal, immediate imaging postinjection, and low radiation burden. In conclusion, it is shown that99mTc-MIBI scintigraphy is a useful procedure in follow-up of thyroid carcinoma and has the potential for visualization of metastasis when131I was negative.