McCormick PA, et al. - Since variable heterogeneous gyriform arterial enhancement on dynamic computed tomography (CT) is one of the striking features of splenic imaging, researchers have tested the premise that these arterial enhancement patterns may reflect changes in splenic micro-circulation associated with changes in venous pressure in the portal. In 55% of patients with transplants, splenic arterial heterogeneity increased compared to 14% in patients with transarterial chemoembolization (TACE) and 4% in patients with waiting lists. Following liver transplantation, heterogeneous gyriform enhancement patterns increase significantly, but not after TACE or patients on waiting lists. Investigators suggested that these changes are due to the decrease in portal venous pressure and probably reflect changes in splenic micro-circulation. In the pathophysiology of hypersplenism, these changes may be important.