67Ga lung scan. An aid in the differential diagnosis of pulmonary embolism and pneumonitis

Abstract

Patients [23] with clinical signs of pulmonary embolic disease and lung infiltrates were studied to determine the value of gallium citrate 67Ga lung scan in differentiating embolic from inflammatory lung disease. In 11 patients with angiographically proved embolism, only 7 had corresponding ventilation-perfusion defects compatible with inflammatory disease. In 7 of these 11 patients, the 67Ga concentration indicated inflammatory disease. In the 12 patients with angiographically proved embolic disease, 6 had corresponding ventilation-perfusion defects compatible with inflammatory disease. None had an accumulation of 67Ga in the area of pulmonary infiltrate. Ventilation-perfusion lung scans are of limited value when lung infiltrates are present. In contrast, the accumulation of 67Ga in the lung indicates an inflammatory process. Ga imaging can help select those patients with lung infiltrates who need angiography.