Abstract Pulmonary ventilation/perfusion SPECT imaging showed an unexpected pattern of perfusion tracer uptake in the kidneys and spleen, raising a suspicion of right-to-left shunting. Further imaging studies confirmed hemodynamically significant shunting due to a persistent left superior vena cava that anomalously drained into the left atrium of the heart.
Maaniitty et al. (Tue,) studied this question.