Lung gammagraphy in pulmonary embolism: relation to pulmonary hypertension, evaluation of therapeutical results

99mTc-MAA (microagregate of human serum albumin) was used in pulmonary perfusion scintigraphy of 15 patients with angiographic proof of pulmonary embolism. The radiopharmaceutical was i.v. administered in a dose of 72 MBq. The size of the pulmonary perfusion defect was determined from posteroanterior and anteroposterior scintigrams using a semiquantitative method. The size of the defect prior to and following anticoagulation or thrombolytic therapy was calculated. The scintigraphic examination showed a relationship between the degree of lung hypertension and the degree of pulmonary circulation obstruction estimated using gammagraphy. It also showed that while significant improvement was recorded in pulmonary perfusion inpatients following anticoagulation and/or thrombolytic therapy, the condition did not resolve completely. The importance of repeated pulmonary perfusion scintigraphy following pulmonary embolism therapy is emphasized for the determination of future therapeutic strategy, i.e., conservative or surgical management. (L.O.) 2 tabs., 4 figs., 11 refs