Radiology Ultrasonography, CT, and MRI 9584b8ee HU units value of bone - A 0 B 40 C -100 D 1000 High-Yield Explanation Ans. is 'd' i.e., +1000 SubstanceHU unitsWaterDense cortical boneSoft tissueFatLung tissueAir0+ 1000 (+400 to + 1000)+ 40 to + 80- 60 to -100- 400 to -600- 1000