Radiology General 5a706d01 In CT scan CT number ranges from: A 0 to 1000 B -1000 to +1000 C 0 to 100 D -100 to +100 High-Yield Explanation “CT Scan” – CT number ranges from – 1000 to +1000: – 1000 = air 0 = water + 1000 = bone (Dense) CT number is called “Housefield number”.