A patient undergoes a CT scan of the abdomen. The Hounsfield unit (HU) value of a hepatic lesion is reported as -60 HU. What does this attenuation value most likely represent?
- A Calcification within the lesion
- B Acute hemorrhage
- C A fat-containing lesion ✓
- D Normal liver parenchyma
Correct answer: C. A fat-containing lesion
Explanation
CT attenuation values are calibrated in Hounsfield units with water defined as 0 HU and air as -1000 HU. Fat has a negative HU value, typically ranging from -20 to -100 HU, due to lower attenuation compared to water. A hepatic lesion with HU of -60 indicates macroscopic fat content, as seen in hepatic angiomyolipoma or a lipid-rich adenoma. Calcification measures above +150 HU. Acute hemorrhage measures +50 to +80 HU. Normal liver parenchyma measures +40 to +60 HU on unenhanced CT.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.