Estimation of entrance skin dose and effective dose from abdomen radiography in two diagnostic facilities in Aba, Abia State, South-East Nigeria

Medical exposure for abdomen radiography is associated with higher doses compared to X-Rays of the chest and other extremities. The study aims to determine the mean entrance skin dose (ESD) for 104 adult patients between 20-89 years with 2 X-Ray units (A and B) in Aba, South-East Nigeria and to determine the ESD at the 75th percentile to estimate the local diagnostic reference levels (LDRLs). This study also determined the effective dose (E), the dose area product (DAP) and the relationship between absorbed dose (DT) and other parameters. This study will also compare its findings with relevant articles where necessary. The study used 2 functional floors mounted X-Ray units. A total of 208 annealed thermoluminescent dosimeters (TLDs) were used made of Lithium Fluoride, doped with Magnesium and Titanium (LiF: Mg, Ti). Two TLD chips were used per patient. The chips were positioned at the anterior and posterior end of the patient respectively for a given beam area for abdomen radiography. After exposure, a calibrated RadPro TLDcube 400 reader (Freiberg Instrument, Germany) was used to estimate individual patient doses. This was done by multiplying the TLD counts by a pre-determined calibration factor (CF). The mean/75th percentile ESD for facilities A and B was 2.92/4.12 and 3.01/3.67 mGy. The E for facilities A and B was 0.73 and 0.82 mSv respectively. There was a good relationship between the DT with ESD, exit dose (ED) and DAP for facility A, but no relationship was seen with other parameters. The mean ESD was lower compared to the National Council on Radiation Protection and Measurements (NCRP 172) and the American Association of Physicists in Medicine (AAPM) reports respectively. The study proved useful and could serve as a reference point to initiate LDRLs within the South-East zone in Nigeria for abdomen radiography