The measurements of CTDIw and DLP in routine CT protocols and comparison with reference dose level in Kashan, Iran

The use of computed tomography (CT) as a diagnostic tool has been considerably increased. Therefore, the controlled and protection-based use of the CT scan is necessary to reduce the detrimental effects of radiation. This study was carried out to determine patient dose level in routine CT protocols and measure CTDIW and DLP in routine CT protocols among adult patients in Kashan Shahid Beheshti Hospital. The CT scanner used, was a single-slice Toshiba model Asteion CXGS-10A. Scan parameters for each protocol were registered for 10 standard-sized patients. Then, the data were applied to the CT system and mean values of CTDIW and DLP were calculated. Finally, the values were compared with the reference dose level. The mean values of CTDIw and DLP for Head, PNS, Chest, Abdomen, and Pelvis protocols were 34.11, 19.67, 15.47, 13.95, 10.08 mGy and 362.67, 153.97, 307.33, 346.07, 189.37 mGy.cm, respectively. The mean values of CTDIW and DLP obtained in all protocols were less and in some of the protocols even less than half compared with the European guidelines and UK reference values. This may be probably due to the mAs and lesser length of scan area. But the mean values of CTDIw in the Chest and Abdomen protocols were greater than IAEA reported values due to reduced use of mAs in this study. To obtain the maximum reduction in patient dose, the lower mAs level with higher KVp, lesser number of slices, length of scan area, and shorter scan time are recommended.