- 900.12(e)(5)(vii)(A)(B)(C): X-ray field/light field/image receptor/compression paddle alignment.
(A) All systems shall have beam-limiting devices that allow the entire chest wall edge of the X-ray field to extend to the chest wall edge of the image receptor and provide means to assure that the X-ray field does not extend beyond any edge of the image receptor by more than 2 percent of the SID.
(B) If a light field that passes through the X-ray beam limitation device is provided, it shall be aligned with the X-ray field so that the total of any misalignment of the edges of the light field and the X-ray field along either the length or the width of the visually defined field at the plane of the breast support surface shall not exceed 2 percent of the SID.
(C) The chest wall edge of the compression paddle shall not extend beyond the chest wall edge of the image receptor by more than one percent of the SID when tested with the compression paddle placed above the breast support surface at a distance equivalent to standard breast thickness. The shadow of the vertical edge of the compression paddle shall not be visible on the image.
- Do the regulations require that the x-ray unit have adjustable collimation on the chest wall edge of the x-ray beam?
- When measuring light field misalignment, must the misalignment at each edge be within 2% of the SID or is it the total misalignment (both edges) in either the length or width dimension that must be within 2% of the SID?
- Do all possible combinations of beam-limiting devices, image receptor sizes, target materials, and focal spots have to be tested during the annual x-ray field/light field/image receptor alignment quality control test?