Dose Absorption in Lumbar and Femoral Dual Energy X-ray Absorptiometry Examinations Using Three Different Scan Modalities : An Anthropomorphic Phantom Study

The aim of this study was to measure the effective dose on an anthropomorphic phantom undergoing lumbar and femoral dual energy X-ray absorption (DXA) examinations, using 3 different scan modalities (fast-array [FA], array [A], high-definition [HD]), and assess the differences in the lifetime attributable risk (LAR) of cancer due to radiation. An anthropomorphic phantom was used. Thermoluminescent dosimeters were placed over 12 anatomic phantom regions and outside the room (to measure background radiation). Fifty scans on the femur and spine were performed for each mode. The dose relative to a single DXA scan for each dosimeter was measured (mean over the 50 scans) and the background radiation was then subtracted. The equivalent dose per organ was obtained. The total body effective dose was calculated by adding the equivalent doses. We estimated the lifetime dose absorption and LAR for cancer for a male and a female patient undergoing 36 DXA studies (18 lumbar, 18 femoral) every 21 months for 32 years. The effective dose for lumbar scans was FA = 17.79 \u3bcSv, A = 32.88 \u3bcSv, HD = 31.08 \u3bcSv; for femoral scans, FA = 5.29 \u3bcSv, A = 9.55 \u3bcSv, HD = 7.54 \u3bcSv. LAR estimation showed a minimal increase in cancer risk (range 4.55 7 10-4% [FA, femoral, male] to 4.02 7 10-3% [A, lumbar, female]). The lifetime dose absorption and LAR for cancer for a male and a female patient undergoing 36 DXA studies (18 lumbar, 18 femoral) every 21 months for 32 years were 0.756 mSv, 3.82 7 10-3% and 0.756 mSv, 5.11 7 10-3%, respectively. DXA examinations cause radiation levels that are comparable to the background radiation. Regardless of the scan modality or the anatomic site, a patient undergoing DXA scans for a lifetime has a negligible increased risk of developing cancer

The Size Effect

At the end of the 20th century, the introduction of so-called \u2018new technologies\u2019 \u2013 advances and innovations \u2013 in various capacities in many sectors, from fashion to media, design and architecture, triggered a process of change that forced a review of methods of design, production, sale and consumption. The result is a revolution that is so radical \u2013 and still ongoing \u2013 that it has led to a redefinition of many of the concepts developed during the industrial age that had previously been accepted as established principles