Assessment of typical (DRL) values, size-specific dose estimates, organ doses and effective doses of adult patients undergoing computed tomography examinations in a university hospital in Brazzaville, Congo Republic

This study aimed to assess typical values, size specific dose estimates, organ doses and effective doses of adult patients undergoing computed tomography (CT) examinations in a university hospital in Brazzaville, Congo Republic. The study involved 308 adult patients of which 51% were female patients and 49% were male patients. Median values of the distribution of dose-length product and volume CT dose index for each CT examination type were defined as typical values in agreement with the ICRP publication 135. Size-Specific Dose Estimates were calculated using the American Association of Physicists in Medicine methodology. Organ doses were computed following a methodology that uses dose coefficients and volume CT dose index. Effective doses were derived using the calculated organ dose values and tissue weighting factors given in ICRP publication 103. Typical values, size-specific dose estimates, organ doses and effective doses determined for female patients were greater than those determined for male patients. The study also showed that chest-abdomen-pelvis and abdomen-pelvis scans were associated with the highest effective dose while the head scan was associated with the lowest effective dose. The overall dose values determined in this study were significantly lower than those reported in selected studies reported in the literature.