On CT, the Hounsfield Unit (HU) value of simple hepatic cyst should be:
- A +20 to +40 HU (soft tissue density)
- B 0 to +10 HU (water density) ✓
- C +70 to +80 HU (acute haemorrhage)
- D -100 HU (fat density)
Correct answer: B. 0 to +10 HU (water density)
Explanation
Simple hepatic cysts are homogeneous, fluid-filled structures with CT attenuation values of 0–10 HU (water/near-water density), well-defined margins, no internal septations, and no wall enhancement. CT Hounsfield scale: water = 0 HU, air = -1000 HU, fat = -50 to -100 HU, soft tissue = 20–80 HU, bone = 300–1000 HU, acute blood/haemorrhage = 50–90 HU, calcification/cortical bone >200 HU. A cyst with HU >20 or enhancement should be classified using the Bosniak system to assess malignant potential.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.