In preparation for 90 Y radioembolization for hepatic malignancies, hepatic angiography is performed with intra-arterial delivery of 99m Tc-macroaggregated albumin (MAA), known as premapping. This initial procedure allows for evaluation of standard/variant hepatic arterial anatomy using MAA as a surrogate marker for the delivery of 90 Y to visualize the likely distribution of 90 Y. Premapping allows for the assessment of at-risk extrahepatic targets and for the quantification of hepatopulmonary shunting. We present cases where MAA scintigraphic images reveal unusual perfusion patterns in hepatic cancers, treated with 90 Y glass microspheres (Therasphere; Boston Scientific, Marlborough, MA).