Delayed MR imaging of the liver: correlation of delayed enhancement of hepatic tumors and pathologic appearance

Background: The value of delayed magnetic resonance (MR) imaging (6 min) and ultradelayed MR imaging (1-4 h) for differentiating of hepatic tumors was studied. Methods: Postcontrast delayed and ultradelayed MR images were obtained after administration of 0.1 mmol/kg of Gd-DTPA in 30 patients with various malignant hepatic tumors. Results: Delayed enhancement in the center of the tumors was seen in 13 patients on the delayed MR images and in 22 patients on the ultradelayed MR images, On the ultradelayed images, peripheral hypointense rim was seen in 12 patients and central focal hypointense area was seen in eight patients. Pathologically, the portion showing delayed enhancement corresponded to abundant fibrous stroma, the hypointense rim to rich proliferation of tumor cells, and the central hypointense areas to coagulative necrosis. Conclusion: Ultradelayed MR imaging can characterize different tissue components within various hepatic tumors.