[123I-IMP clearance of the lung in pneumoconiosis]

We studied 123I-IMP lung clearance on 10 cases of pneumoconiosis and compared it with the data of 5 non-smoking young adults. After the venous injection of 111 MBq of 123I-IMP we collected the lung dynamic data using 1 frames/10 sec for 10 minutes and 1 frame/min for following 40 minutes. The time activity curve after the injection of 123I-IMP was obtained as follows: C(t) = A1e-k1t divided by A2e-k2t (k1, k2: slopes of the exponential component at the early and delayed phase). The 123I-IMP clearance was delayed in the patients group especially on the early phase and the k1 was lower than that of the normal group. Our results indicate that the pulmonary blood flow of the patients with pneumoconiosis decreased because of the advanced fibrotic change. This dynamic analysis may prove useful for the evaluation of the pneumoconiosis objectively and quantitatively.