Abstract
Using perfusion lung scintigraphy with Tc-99 m MAA, pulmonary perfusion in the contralateral lung of the primary focus was analyzed in 425 cases with primary lung cancer. Perfusion abnormalities in the contralateral lung were observed in 318 of 425 cases (74.8%), and the causes of hypoperfusion were known in 210 cases (66.0%) and unknown in 108 cases (34.0%). Hypoperfusion due to carcinomatous causes, in which intrapulmonary metastasis was the most frequent, was observed in 154 cases and more frequently in cases with adenocarcinoma, T3, N2, Ml, and stage 4 by TNM staging. Hypoperfusion due to non-carcinomatous causes, in which pleural thickening or adhesion was the most frequent, was observed in 172 cases. Hypoperfusion of unknown causes was found more frequently in cases with squamous cell carcinoma, small cell carcinoma, T3, N1, N2, stage 2, 3 and 4 by TNM staging and elevated serum fibrin degradation products. In 119 autopsied cases, various changes of the intrathoracic organs were revealed, and incidences of some changes in the contralateral hemithorax of the primary focus, such as intrapulmonary metastasis, bronchopneumonia, non-specific pleurisy and pulmonary embolism, were approximately equal to those in the ipsilateral hemithorax.
Perfusion lung scintigraphy is of special significance to understand the disease process and pathophysiology of pulmonary perfusion, and especially to estimate pulmonary perfusion abnormality in the contralateral lung of the primary focus, which could reveal various intrathoracic changes of carcinomatous and non-carcinomatous origins.
