If the replacement includes the AEC detector, the medical physicist must evaluate the assembly prior to use on patients. If, however, the installation does not involve the replacement of the AEC detector(s) on the system, the exchange of bucky assemblies would not be considered a major repair and would therefore not require the medical physicist to evaluate the assembly prior to use on patients. There are tests that should be performed when the bucky is replaced (table artifacts, grid artifacts, and x-ray field/image receptor alignment). These particular tests require evaluation of images obtained with the new or modified equipment. In many cases, such images may be generated by facility personnel in consultation with the medical physicist but do not require the medical physicist to be physically present in the facility. The images may then be sent to the medical physicist for evaluation. If approved by the medical physicist, the facility may begin using the equipment. The medical physicist can then repeat the tests at the next annual survey.