Multi-slice CT examinations of adult patients at Sudanese hospitals: radiation exposure based on size-specific dose estimates (SSDE)

The aim of this study was to update the radiation exposure for adult patients undergoing multi-slice CT (MSCT) examinations using size-specific dose estimates (SSDE). Console, displayed CTDI_vol and scan parameters were retrospectively recorded for 423 adult patients in seven Sudanese hospitals. Patient torso diameters were measured using digital calipers on the scanner console. SSDE was determined based on transverse images (SSDE_trans) and scout radiographs (SSDE_sco). Size-specific conversion factors were used to translate the recorded CTDI_vol into SSDE according to the procedure described in the American Association of Physicists in Medicine (AAPM) Report 204. In chest CT, mean CTDI_vol, SSDE_trans and SSDE_sco ranged: from 4.3 to 47.5 mGy (average: 12.8), 5.5 to 70.3 mGy (average: 18.6) and 5.8 to 63.5 mGy (average: 18.7), respectively. In abdominal CT, mean CTDI_vol, SSDE_trans and SSDE_sco ranged: from 4.0 to 74.5 mGy (average: 16), 5.5 to 152.8 mGy (average: 23.9) and 6.0 to 151.3 mGy (average: 25.21), respectively. Our study highlights the relationships between CT dose and patient dimensions measured from scout and transverse CT images. The correlations between the patient size and dose based on scout images were less significant than that based on transverse images. High dose levels and dose variations among hospitals reveal the need for standardization of scanning protocols and staff training on adoption of scanners’ dose reduction techniques.