The design of the phantom permits reduction of all sources of error within acceptable limits. Careful and precise manufacturing and quality controls insure that all phantoms are identical in order to create a general and uniform standard applicable to all scanners. The basic principle of operation is to sufficiently simulate the patient’s anatomy, and then to scan the patient and the phantom in succession with identical technical factors. The CT simulator for bone mineral analysis works with all CT Scanners and permits serial examinations of the patient irrespective of scanner use. Data interpretation and analysis can be performed “off line” to eliminate unnecessary scanner time. Numerous options available.