Abstract
The Monte Carlo package PCXMC was used to determine the effect of source to image distance (SID) on effective dose to the patient in diagnostic radiology. A range of common examinations was used, with a range of distances from 75cm to 200cm. The results showed that the radiation risk (effective dose) is virtually independent of the SID. In cases where a radiation sensitive organ is close to the edge of the x-ray field, the effective dose increases slightly with distance. In other cases there was either no dependence, or a small reduction in risk with increasing SID. There is therefore no justification in terms of radiation risk for a change in the standard SID of 1m that is currently used for most projections.
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Poletti, J. The effect of source to image distance on radiation risk to the patient. Australas. Phys. Eng. Sci. Med. 26, 110–114 (2003). https://doi.org/10.1007/BF03178779
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DOI: https://doi.org/10.1007/BF03178779