Mammography (MG), CT, and MRI, designated the specific medical imaging equipments, were assessed for quality control. This study aims to inspect the relationship of the deterioration level and failure rates of the specific medical imaging equipments.

The complete results of the quality control exam of MG and CT from 2006 to 2011 and those of MRI from 2007 to 2011 were analyzed. There were three standards for analysis: the type of exam, the written or detailed exam; the deterioration level, at more or less than 10 years after manufacture; the type of institution, the general hospital, district hospital, or clinic. We excluded the data of reexaminations to avoid the overlap and the equipments of unknown manufacture year.

The failure rates of MG had decreased, and the differences by the deterioration level or type of medical institution had disappeared also. In case of CT, the failure rate of old equipment was consistently high, but the overall failure rates of CT had decreased. The overall failure rates of MRI were low, and there were no differences of the failure rates by the deterioration level.

The effects of the deterioration level, more or less than 10 years after manufacture, would be limited to the performance of MG and CT.