Incidental Detection of Persistent Left Superior Vena Cava During Lung Perfusion Scan

Lung perfusion scintigraphy is a cornerstone for evaluating pulmonary embolism but may reveal unexpected vascular anomalies. Persistent left superior vena cava, a congenital anomaly, can cause a right-to-left shunt when draining into the left atrium, bypassing pulmonary circulation. We report the incidental detection of persistent left superior vena cava during lung perfusion scintigraphy in a patient with post-COVID-19 hypoxia. Dual-site radiotracer injections and SPECT/CT confirmed the diagnosis, highlighting the need for adaptive imaging techniques to accurately interpret atypical findings in nuclear medicine.