A simple method to measure of radioactivity on the lungs in 99mTc-Technegas inhalation study

99mTc-Technegas inhalation scintigraphy is replacing ventilation scintigraphy using radioactive inert gas. 99mTc-Technegas, which is carbon nanoparticles, has a characteristic of a smaller and uniform particle size. When 99mTc-Technegas is inhaled into the lungs of patients, it is promising to perform the inhalation in an additional space because the inhalation procedure probably results in an equipment and floor contamination, which gives radiation exposure to staffs. The method mentioned above needs to measure 99mTc radioactivity in the lungs. The aim of this study was to design simple measurement using phantom study. Radioactivity of a phantom was obtained by using an ionization chamber survey meter. Radioactivity in the lungs of patients who inhaled 99mTc-Technegas was measured by using an ionization chamber survey meter, correlated with the radioactivity of the phantom data. Our established method was able to accurately and simply measure radioactivity of the lungs in all of the patients who underwent 99mTc-Technegas inhalation study. (author)