Patient doses received during whole body scanning using an Elscint 905 CT scanner.

Abstract

In large X-ray departments, whole-body scanners are now the rule rather than the exception and more uses are being found for the particular way they can record anatomical structures. A knowledge of the dose distribution during different investigations is important as computed X-ray tomography has opened up new areas of research where some of the doses will be received by volunteers. The results reported in this paper were obtained during investigations using an Elscint Exel 905 CT scanner. This scanner utilises a collimated X-ray beam at 3 kW output for planar scans, and 6 kW output for transverse section scanning. The X-ray detectors consist of 52 bismuth germanate oxide crystals, and the motion of the source and detectors is to translate/rotate in a clockwise direction. The full scan angle is 180° (5 × 36°), and as a consequence the dose distribution around the circumference of a section is uneven. In addition to the inherent filtration (2.5 mm Al equivalent) as required by ICRP (1970), a further filter...