title: [Evaluation of regional pulmonary function test using 11C02, 11C0 and 13N2].
abstract: In the present study an attempt was made to evaluate the regional pulmonary function tests using positron gases and comparative studies of pulmonary functions were made using these positron gases and the conventional radioisotopes. In this study, 11CO2, 11CO, and 13N2 were used as positron study and then both 133Xe and 99mTc-MAA were used as conventional study. As fundamental tests, we measured the full width at half maximum (FWHM) of the line source of these nuclides and then measured the depth response of energy of these nuclides using the source in water. The subjects comprised normal control subjects, chronic obstructive pulmonary diseases (COPD), pulmonary fibrosis etc. as clinical tests. A single image or sequence of dynamic images were photographed by scintillation camera (Searle Pho-Gamma LFOV) equipped with a high energy collimator for positron and simultaneously the data were collected by computer. The detector of the scintillation camera was positioned in the posterior projection of the chest in a sitting position. A single breath method was used and after a short period of breath holding (10-20 min.), the inspired gas washed out for rebreathing room air. From the dynamic images, wash out curve and clearance rate were extracted with the aid of computer. The right lung field was divided into two zones, the upper and lower zones and upper/lower ratio (U/L ratio) of pulmonary distribution or clearance rate (C.R.) were calculated. As fundamental evaluation, resolving distance between positron and 133Xe were similar. But positron was best depth response of gamma-ray energy of the used nuclides. Clinically, 13N2 study and 133Xe study were similar.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D002245:Carbon Dioxide; D002250:Carbon Radioisotopes; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000000981:diagnostic imaging; D009590:Nitrogen Radioisotopes; D011652:Pulmonary Circulation; D011653:Pulmonary Diffusing Capacity; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D014692:Ventilation-Perfusion Ratio
chemical_list: D002250:Carbon Radioisotopes; D009590:Nitrogen Radioisotopes; D002245:Carbon Dioxide