967 Minimizing Radiation Dose in Non-Contrast CT KUB for Ureteric Colic

Aim To assess current local practice in CT KUB imaging alongside national data aimed at minimising the radiation doses & adherence to accepted practice. Method We undertook a retrospective analysis of 104 non-contrast CT KUB in July 2022 for patients with suspected renal/ureteric colic. PACS images were individually reviewed to assess the cranial level at which scan commences & level at which kidneys start. Data was collected and radiation Doses monitored in milliGrey (mGy) (standardized measure of radiation dose output of a CT scanner). Results A total of 104 non-contrast CT KUB was included where 50 (49% ) scans commenced from superior border of T10- T12 Level & 52 (51%) of scans commenced above T10- T12 Level. A further 1% started below T12 level. Only 1% (1) of scans showed upper poles of left kidney above T10. Individuals scanned at T10 or below (50/104) received on average 6.9mGy of radiation while individuals scanned at levels above T10 (52/104) received on average 9.82mGy of radiation. Conclusions Our results show 51% of scans commenced above the recommended level (T10) which exposed individuals to higher amounts of radiation on average than individuals whose scans commenced at or below the accepted level of T10. This concludes that more than half of the people who underwent CT KUB scans were exposed unnecessarily to higher radiation doses than the published diagnostic reference levels (NDRL).