(A) Xenon 133 ventilation imaging demonstrates an elevated right hemidiaphragm but no ventilation defects on single-breath/early wash-in. However, on washout there is an unusual abnormal appearance of radiotracer surrounding the right lung and also involving the major fissure (circle). (B) Tc99m-MAA perfusion imaging demonstrates multiple bilateral medium and large mismatched perfusion defects (arrows).

Differential Diagnosis