Patient 10. Portal vein tumor thrombosis in a large heterogeneous HCC. (a, b) Catheter-directed CT angiogram of the right hepatic artery demonstrates contrast enhancement within portal vein tumor thrombosis (arrow). (c, d)90Y PET/CT depicts focal 90Y activity within the portal vein tumor thrombus in high resolution. (e, f) The same activity is poorly visualized on 90Y bremsstrahlung SPECT/CT as subtle, ill-defined activity.