Purpose: To evaluate the causes of intrahepatic segmental areas of signal hypointensity [corrected] on T1- and T2-weighted spin-echo (SE) and gradient-echo (GRE) magnetic resonance (MR) images.
Materials and methods: Six patients in whom wedge-shaped hypointense areas were seen on hepatic MR images underwent examination with ultrasound (US), computed tomography (CT), angiography, and CT during arterial portography (CTAP). Histologic examination was performed in three patients.
Results: The affected liver parenchymas were best depicted as segmental or lobar hypointense areas on GRE images. Angiography and CTAP revealed that portal blood supply to the hypointense areas was absent or decreased due to portal vein tumor thrombus and arterioportal shunt (n = 1), compression of a portal branch by tumor (n = 2), portal vein thrombosis (n = 1), or arterioportal shunt (n = 2). Iron deposition in the hepatocytes was evident in all three patients with histologic correlation.
Conclusion: Segmental signal hypocoagulability was generally due to hepatocyte iron deposition and was accompanied and possibly caused by a disturbance in portal flow.