Role and interpretation of lung scintigraphy for long-term management of pulmonary embolism.

The long-term management of patients after pulmonary embolism (PE) remains a major challenge, owing to the risk of persistent symptoms, complications, and recurrence. Residual pulmonary vascular obstruction (RPVO) is common, affecting up to 50% of patients after six months of anticoagulation. Ventilation-perfusion (V/Q) scintigraphy is the imaging modality of choice for detecting RPVO, which typically presents as mismatched perfusion defects, as it offers a sensitivity superior to that of computed tomography pulmonary angiography (CTPA), together with lower radiation exposure and the absence of iodinated contrast agents. V/Q scintigraphy plays a pivotal role in the screening of chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic pulmonary disease (CTEPD). Furthermore, follow-up V/Q scintigraphy may aid in the diagnosis of recurrent PE and in predicting recurrence risk.