[Evaluation of delayed I-123 IMP lung studies in atelectatic and inflammatory diseases in comparison with Ga-67-citrate scintigraphy].

We have previously reported that increased tracer accumulation on delayed 123I-IMP scintigraphy is associated with atelectasis and inflammation. The purpose of this study was to evaluate the diagnostic values of delayed 123I-IMP lung scintigraphy, compared with gallium scintigraphy. Ten patients with atelectasis caused by lung cancer and 7 patients with inflammatory diseases were studied. Inflammatory lung disease included 4 cases of pneumonia, 2 of interstitial pneumonitis, and 1 of diffuse panbronchiolitis. Delayed 123I-IMP scintigraphy was performed 24 hours after intravenous injection of 111 MBq of 123I-IMP. In 14 patients, the SPECT images were obtained. Gallium scintigraphy was done within 7 days of 123I-IMP scintigraphy and the images were obtained 72 hours after the administration of 111 MBq of 67Ga-citrate. 123I-IMP scintigraphy was compared with gallium scintigraphy for its ability to detect atelectasis. The degree of uptake by the collapsed lobes was judged visually on planar images and rated using four grades: negative, slight, moderate and heavy. All the cases showed moderate or intense uptake on the 123I-IMP images, whereas with gallium scintigraphy there was no change corresponding with lobar collapse in 8 out of 10 cases. Of the remaining 2 cases, one had tumor in the collapsed lobe and the other had obstructive pneumonia. In inflammatory lung diseases, the correlation of 123I-IMP and gallium images regarding degree of change shown on chest X-ray film was studied. The degree of correlation was classified using four grade: poor, fair, good and excellent.(ABSTRACT TRUNCATED AT 250 WORDS)