A method of and apparatus for measuring bone density

摘要

An X-ray system is provided with a narrow fan beam (36A) to scan patients for bone density and soft tissue body composition. In addition to single pass scanning of body parts such as the spine, hip and forearm, a method for multiple pass whole body scanning is used. The system includes a movable scan table (16) configured to support a patient and a C-arm (18) associated with the table. The C-arm (18) supports an x-ray source (36) and an x-ray detector (38) at opposite sides of the patient. A scanning mechanism (44,52) is provided to move the surface (16A) of the scan table (16) and the C-arm (18) to scan the patient with overlapping adjacent x-ray fan beams (36A) in successive passes along the length of the patient. A scan pass combination scheme that blends areas of overlap is employed to compensate errors related to height dependency. The blending is performed according to the height of the part of patient scanned in the overlap and the distance from the edge of the scan pass.