Analysis of reject x-ray films as quality assurance element in diagnostic radiology

Purpose: Analysis of reject films from a large radiological department under the following aspects: How big is the waste of films? Where are the sources of error? What are the possible means of quality assurance? Material and method: During a total period of 9 months, separated into three quarters, 14570 reject films were analysed and assigned to 4 categories (''positioning'', ''exposure'', ''reject films due to patients'' and ''others''). In addition they were classified according to the respective parts of the body. The influence of a ''study effect'' was quantified by the analysis before and after information of staff. Results: The reject film rate in relation to all performed x-rays, was 9.0-13.2% of all the films taken during that period; of these, the failure rate (x-rays useless for diagnosis because of their bad quality) was between 54.2 and 57.5%. In this category, the main sources of error were positioning (55%) and exposure (34%). Surprisingly, the technical film waste amounted to 42.5-45.8% (not developed or preexposed films, x-rays of phantoms etc.). Conclusion: Wasted films due to errors occurring during taking, as well as technical film waste, are unavoidable. Their proportion in relation to the total number of films should not exceed 8%. The main approach to reducing cost must be to cut down technical film waste.