We use FDA's guidance for mobile facilities where we produce a phantom image after a move of the mobile unit and we monitor the mAs. We then process the phantom image later, prior to processing the mammograms. If we move the mobile unit more than once per week, do we also have to produce a weekly phantom image in addition to the phantom produced after each move?
If you use the mode of operation and/or technique factors used clinically for a standard breast for the phantom images that you produce after each move, you do not have to perform an additional weekly phantom image. However, the image used for the weekly phantom test must be evaluated for all required density measurements in addition to the object scores. 21 C.F.R. 900.12(e)(2).