Thursday, December 20, 2018

MRI Hepatic Lesion Differential Diagnosis

This post is derived from notes I took during training. Any images are copyright their respective owners.

Focal nodular hyperplasia (FNH)
  • Demographics: young women 
  • Pathology: localized hyperplastic hepatocyte response to an underlying congenital arteriovenous malformation 
  • MR: fibrous central scar that is T2↑, T1↓ with delayed, enhancing scar 
  • US: internal vascularity in spoke wheel configuration 
  • NM: Uptake ↑ on sulfur colloid scan due to Kupffer cell uptake. HIDA positive. 
  • Differential: Adenoma (photopenic on sulfur colloid)

Hepatic adenoma
  • Demographics: Young women on contraceptives
  • MR: mixture of fat, hemorrhage, necrosis; fat will be T1 bright, drops out on opposed phase imaging; may see internal vascularity / hyperintense capsule; if bleeding, may see hematoma as below 
  • Management: Monitor for size; if greater than 4 cm, treat because of bleeding risk

Hepatic hemangioma

  • Most common benign liver mass, not prone to spontaneous bleeding 
  • US: Homogeneously echogenic with no flow on Doppler. Never see hypoechoic halo. 
  • CT/MR: typically early discontinuous nodular filling, fills centripetally
    if cavernous/large, may have central hypointense scar +/- calcification 
  • NM: delayed blood pool activity on Tc99m RBC has nearly 100% PPV

Hepatocellular carcinoma (HCC)
  • Demographics: older pts 
  • Pathology: associated with cirrhosis; MC primary hepatic malignancy. AFP elevated. 
  • MRI: hypointense but with rapid uptake and early washout. Portal vein invasion. 
  • Differential: regenerative nodules (not hypervascular, no PV invasion), regenerative nodular hyperplasia (associated with Budd-Chiari, resemble FNH) 
  • Treatment: Chemo, Ablation, Surgery 
Fibrolamellar HCC
  • Demographics: young adults, may have h/o hepatitis 
  • CT/MRI: Large, calcified central scar; heterogeneous appearance 
  • Differential: FNH (smaller, older patients, more homogeneous appearance, enhancing scar)

  • Children: Neuroblastoma (Stage 4 & 4S), Burkitt, Wilms, AML, Sarcomas 
  • Adults: 
    • Hyperechoic: Colon, RCC, Breast (either), Carcinoid, Chorio 
    • Hypoechoic: Breast (either), pancreas, lung, lymphoma 
    • Calcified: colon (mucinous type), gastric, osteosarcoma (rare) 
    • Cystic: ovarian cystadenoca, GI sarcoma 
    • US: hypoechoic rim (target sign)



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