A Comparison of the Mean CTDIvol and DLP Values for Adult Abdominal CT Examination for MTRH, Eldoret Hospital, St. Luke’s Hospital and Mediheal Hospital: A Retrospective Study

Abstract

Background: Advances in Computed Tomography (CT) have facilitated widespread use of medical imaging while increasing patient lifetime exposure to ionizing radiation. In Kenya we use the international DRLs as our point of reference and so far, no regional protocols for abdominal CT scan have been adopted. This study endeavors to form a basis for dose reference levels protocols for abdominal CT scan in Uasin Gishu County. Objective: To compare the mean CTDIvol and DLP values for adult abdominal CT examination for MTRH, Eldoret Hospital, St. Luke’s Hospital and Mediheal Hospital. Methods: This was a retrospective review of CT scans of 700 adult patients conducted in Uasin Gishu healthcare system at MTRH, Eldoret Hospital, Mediheal Hospital and St. Luke’s Hospital in a period of 1 year in the year 2021 using systematic and consecutive sampling. The Volumetric CT-dose index (CTDIvol) and dose length product (DLP) length from CT abdominal scans for the adults were collected from the various CT scans dose tracking software’s. Results: The mean age of patients who underwent CT abdominal scans was 52 years with majority being females at 53 %. The mean CTDIvol was 81. (SD=22.2) and the mean DLP values was 1699.1 (SD=1053.1). Comparison by scan model demonstrated the median for the Total DLP and for the CTDIvol significantly differed by the model with the median for the Neusoft model being highest at 2538 mGy.cm and 10.3mGy respectively while those for the Siemens were the lowest for the two markers at 1318.5 mGy.cm for the DLP and 5.39mGy respectively. These findings were statistically significant with a p value of < 0.001. Comparison by the type of facility showed that the median DLP and CTDIvol values were significantly higher in the public facilities at 1668.8mGy.cm and 6.3mGy respectively when compared to private facilities at 1282.4mGy.cm and 5.9mGy with a p value of <0.001. The Local Dose reference level (LDRL) was set as the median value for CTDIVOL and DLP at 6.1mGy and 1465 mGy.cm respectively. Conclusions: The LDRLs for the patients undergoing abdominal CT examination in Uasin Gishu healthcare system were markedly lower than the regional and the international values for the same abdominal CT examination.