Liver Lesions with Arterial Enhancement and Retained Intensity in the Portal Venous Phase with Diffusion Restriction

The differential diagnosis for liver lesions that exhibit arterial enhancement, retained intensity in the portal venous phase, and diffusion restriction can be categorized as follows:

• Single Most Likely Diagnosis

  • Hepatocellular carcinoma (HCC): This is the most common primary liver malignancy, especially in patients with cirrhosis. HCC typically shows arterial enhancement due to its blood supply from the hepatic artery and may retain intensity in the portal venous phase. Diffusion restriction is also common due to the high cellular density of the tumor.

• Other Likely Diagnoses

  • Focal Nodular Hyperplasia (FNH): Although less common than HCC, FNH can exhibit arterial enhancement and may show retained intensity in the portal venous phase. However, diffusion restriction is less typical for FNH compared to HCC.
  • Intrahepatic cholangiocarcinoma: This malignancy can also show arterial enhancement and diffusion restriction, although its imaging characteristics can be more variable than HCC.

• Do Not Miss Diagnoses

  • Metastases: Certain metastatic lesions to the liver, such as those from neuroendocrine tumors, renal cell carcinoma, or breast cancer, can exhibit arterial enhancement and may have diffusion restriction. Missing these diagnoses could significantly impact patient management and prognosis.
  • Inflammatory or infectious lesions: Abscesses or inflammatory pseudotumors can show arterial enhancement and diffusion restriction due to their high cellular content and inflammation. These conditions require prompt diagnosis and treatment to avoid serious complications.

• Rare Diagnoses

  • Hepatic adenoma with malignant transformation: While rare, hepatic adenomas can undergo malignant transformation to HCC, and their imaging characteristics can overlap with those of HCC, including arterial enhancement and diffusion restriction.
  • Biliary hamartomas (von Meyenburg complexes): These benign lesions are typically small and multiple, showing arterial enhancement, but they are less likely to exhibit significant diffusion restriction compared to malignant lesions.
  • Primary liver lymphoma: This is a rare condition that can present with liver masses showing arterial enhancement and diffusion restriction, although it is much less common than other liver malignancies.