Perfusion Scan: Pulmonary Emboli

An abnormal nuclear lung scan taken from the front shows areas without nuclear particles (arrows). This finding indicates that pulmonary emboli (blood clots) may be present. A normal lung scan is shown on the right for comparison.

(From AP Fishman, Pulmonary Diseases and Disorders, 1 ed, 1980, McGraw-Hill, Fig. 164-8 and 161-4; with permission.)