ABSTRACT
Background: to suggest South India CT diagnostic reference levels [DRLs] by collecting radiation doses for the most commonly performed CT examinations
Materials and Methods: a pilot study investigated the most frequent CT examinations. 110 CT sites were asked to complete a survey booklet to allow the recording of CT parameters for each of 3 CT examinations during a 1 year time period. Dose data such Volumetric Computed Tomography Dose Index [CTDI[v]] and Dose length product [DLP] on a minimum of 50 average-sized patients in each category were recorded to calculate a mean site CTDI[vol] and DLP value. The rounded 75[th]percentile was used to calculate a DRL for each site and the region by compiling all results. Results are compared with international DRL data
Results: data were collected for 16,500 patients. All equipment had multislice capability [2-256 slices]. DRLs are proposed using CTDI[vol] [mGy] and DLP [mGy.cm] for CT head [47 and 1041 respectively], CT chest [10 and 445 respectively], and CT abdomen [12 and 550 respectively]. These values are lower than current DRLs and comparable to other international studies. Wide variations in mean doses are noted across the region
Conclusion: baseline figures for South India CT DRLs are provided on the most frequently performed CT examinations. It was noted that there was a wide variation in mean doses among the CT scanners used during diagnosis. The differences in CT doses between CT scanner departments as well as identical scanners suggest a large potential for optimization of examinations