Use of a Smaller Size Phantom When Measuring Scatter Radiation in Diagnostic and Interventional Radiology

Abstract

Regular control of X-ray installations includes radiation protection tests. Scattered radiation is measured in a standardised environment, using phantoms that simulate patients. In this paper, we investigated the possibility to use smaller size phantoms when measuring scatter radiation in diagnostic and interventional radiology. We examined how ambient dose equivalent is changing with different characteristics of the primary beam and phantom sizes. The source of radiation was a radiographic X-ray unit equipped with the possibility to change the exposure time and current individually. Measurements were done using three ionisation chambers. During the measurement procedure distance from the source of scattered radiation to the detector was changed. Two phantoms characterised by different size were used. Inconsistency was noted between different instruments during the measurements at distances close to the centre of the primary field. This can be attributed either to different dimensions of ionisation chambers or to non-uniformly scattered radiation. Other results are in accordance with the expectations. Use of smaller-sized phantoms is possible with the use of appropriate correction factors.