<prompt> Attenuation value Hounsfield unit of -1000 represents which of the following?AirMuscleBoneBlood  <response>: The HU for common substance: SUBSTANCE HU Air -1000 Fat -120 Range -50 to -120 Water 0 Blood 30 to 45 Muscle 40 Contrast 130 Bone 400 Reference: Essential Radiology By S.Bhadury, 2nd Edition, Page 23 