While the systems have significant physical differences, FDA treats them the same from an MQSA regulatory standpoint. CR systems are considered part of the mammographic modality known as FFDM. This means that facilities wishing to use a CR system must meet all applicable MQSA requirements (21 CFR Part 900), including those specific to FFDM units. For example, all personnel using a CR system must have completed at least 8 hours of training specific to digital mammography prior to using the new CR system on patients (21 CFR 900.12(a)(1)(ii)(C), (a)(2)(iii)(E), (a)(3)(iii)(C)). However, because CR systems are part of the FFDM mammographic modality, personnel who have already obtained 8 hours of training in FFDM do not have to obtain another 8 hours in CR prior to use on patients.