PULMONARY SPECT IMAGING AND THE STRIPE SIGN

A patient with high clinical suspicion for pulmonary embolism underwen t a diagnostic scintigraphic ventilation/perfusion scan. The planar im ages revealed an unmatched perfusion defect with a stripe sign in the right middle lobe, A stripe sign is the appearance of normally perfuse d tissue between the defect and the pleural surface suggesting a nonpl eural-based abnormality, SPECT images acquired in the same study perio d, however, failed to demonstrate normally perfused tissue between the defect and the pleural surface, Previous studies have compared planar ventilation/perfusion studies with stripe sign perfusion defects to p ulmonary angiography, The results suggest that stripe sign perfusion d efects are generally not due to emboli, However, planar imaging is pro jectional and may miss pleural contact in some perfusion lesions depen ding on the projection. In the absence of SPECT data, the significance of the stripe sign may need to be reassessed.