<prompt> Hounsfield unit of 200-250 in CT indicatesFatCalcificationsAcute bleedCSF  <response>: The reference value for Hounsfield unit is 0 - seen with CSF or Water HU of -50 - -100 is seen with fat HU of -1000 is seen with air Appears hypodense HU of 60 to 70 - Acute bleed HU of 130 - Contrast HU of 200 to 250 - Calcifications HU of 400 to 1000 -Coical bone Appears hyperdense 