The Absorbed Dose by Postmenopausal Women Using Bone Mineral Densitometry in Dual Energy X-Ray Absorptiometry and Its Relationship with Height, Weight and Body Mass Index

The purpose of this study was to assess the entrance surface dose (ESD) and effective doses (ED) in postmenopausal women using dual energy X-ray absorptiometry (DXA). It also tried to determine the correlations between ESD and ED and height, weight and body mass index (BMI). Thermo luminescent dosimeters (TLD-GR200) and abdominal CT scans were used for patient dosimetry. The correlation coefficients and regression analysis was applied for 43 postmenopausal women who referred to Seyed Alshohada Hospital in Isfahan. Pearson's correlation analysis showed that there was a significant correlation between ESD and BMI (r = 0.885; P < 0.001) and weight (r = 0745; P < 0.001). However, there was an indirect correlation between ESD and height (r = -0.258; P = 0.047). Pearson's correlation analysis also showed an indirect correlation between ED and BMI (r = -0.651; P < 0.001), height (r = -0.346; P < 0.001) and weight (r = -0.811; P < 0.001). Mean values of ED and ESD were respectively determined as 0.50 µSv (0.26-0.95) and 9.54 µSv (7.25-12.65) for the anterior posterior (AP) spine scans. Our results showed that the exposure in bone densitometry with a Norland XR-46 system was very low (0.50 µSv). In fact, these values were much lower than the average daily background in the UK (7 µSv).