Optimization of Radiation Protection of Patients in Mammography Examinations using compression analysis

Abstract

Compression force, compression alignment and compression thickness have been studied on thirteen (13) mammography systems in Ghana to help in the optimization of the mammography process. The objective of this study was to check that the mammography system provides adequate compression in manual and automatic (power) mode; to check the accuracy of the compression force indicator, if present on the equipment and to check the accuracy (or deviation) of the compression thickness indicator. The alignment of the compression device at maximum force was also visualized and measured. The tests were conducted using the International Atomic Energy Agency Human Health Series 2 and 17 and the European guidelines for quality assurance in breast cancer screening and diagnosis protocols. Results from the test shows that systems A - C, E, H - M, all passed the compression force (both Manual and Power) test. System G failed the Power compression force test. The test was not performed on systems D and F. System F failed manual compression test. It was realised that even though system I passed the test, it was observed that the compression plate lacked the needed force to compress the breast. System G failed the compression thickness test completely whiles system H failed the test for the 45mm thick PMMA phantom. Values from the compression alignment test, Left Difference (rear - front) and Right Difference (rear - front) for system E were outside the tolerance limit of ? 5mm. Their values represents misalignment of the compression plate. It is recommended that the compression force system for system F must be replaced. The compression plate for systems E, G and H must be changed since they are misaligned and do not offer the best for the patient.