Radiological safety survey of medical radiographic equipment

The areas of concern in a medical X-ray equipment are the focal spot, filtration, collimation, kVp calibration, timer accuracy, and exposure linearity, alignment of tube and image receptor, all of which impact exposure. This paper presents an analysis of historical data on 284 X-ray equipment over a 5-year period based on field measurements using well-defined protocols prepared by the National Regulatory Authority responsible for regulating the activities of users of ionizing radiation nationwide. All the data were collected and recorded for posterior analysis and subsequent preparation of quality control reports to be submitted to clients. The safety parameters assessed were the kVp accuracy, mA linearity, half-value layer, collimation accuracy, X-ray/light beam perpendicularity, and the timer accuracy. An electronic parameter such as the kVp which is important not only for radiation protection, but also for image quality showed significant improvements. Again, only 57% of conventional X-ray systems showed kVp conformity in 2010, a percentage that improved to 89% in 2014. Mobile X-ray systems showed an increase in this conformity index from 50% in 2010 to 84% in 2014. All these improvements were attributed to the continuous and extensive enforcement of the provisions of the legislation (Legislative Instrument 1559, Ghana, 1993). (author)