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Objective: to conduct the study of age distribution of bone mineral density (BMD) by the database of dualenergy X-ray absorptiometry (DXA) and to compare it with datа of population NHANES study. Material and methods. We used data from the densitometry of three-zone (total hip (TH), femoral neck (FN), and lumbar spine) measured by DXA from two outpatient clinics. The obtained data were compared with NHANES III for TH and FN and with NHANES 2005-08 for lumbar spine. The BMD value was corrected with the calibration coefficient for each DXA scanner. Adjustments were also made for the population distribution by sex and age. Results. Compared with NHANES for FN and TH, the obtained BMD values were significantly decreased for patients aged less than 50 years (men and women). The BMD values for FN and TH were unsignificantly decreased in men older 50 years. In women older 50 years unsignificantly decreased BMD values for FN and a significantly increased BMD values for TH were observed. The BMD values were decreased for lumbar spine in men and women throughout this age interval (more than 50 years old). Conclusion. The population BMD distribution in men and women was assessed by DXA method. The obtained dependence of the BMD for FN in women older 50 years was in good agreement with the results given by Russian and foreign authors.

The aim – to determine the possibility of identifying individuals with osteoporosis using asynchronous computed quantitative tomography (CT) of the proximal femur by comparison with dual-energy X-ray absorptiometry (DХA).Materials and methods. The study included 40 postmenopausal women and 6 men over 50 years old (Me of age – 72.5 [65.3; 77.7] years) referred by the attending physician for densitometric examination. The patients signed an informed consent. The measurements were performed on a DXA with a narrow fan beam (Lunar Prodigy Advance, GE Healthcare, USA), and QCT on the Aquilion 64 (Canon Medical Systems, Japan). Correlation analysis and comparison of projected bone mineral density (BMD), bone mineral content (BMC), measurement area and T-score using the Blend – Altman method were carried out.Results. A statistically significant correlations were revealed between the indicators of DXA and asynchronous QCT: for femoral neck BMD r=0.93; for the T-score r=0.93; for the total hip – r=0.91 and r=0.91 respectively. When conducting the analysis using the Blend – Altman method, it was found that the QCT underestimated the value of the femoral neck BMC (bias –0.923 g), covered a smaller area of interest (bias 0.376 cm2 ), and therefore there was a shift in the values of BMD by –0.224 g/cm2 . The value of the T-score for the femoral neck had bias –0.29 standard deviations (SD), and for the total hip –0.72 SD, which were statistically significant.Conclusions. There was a high correlation between quantitative indicators of bone tissue of the proximal hip, assessed using QCT and DXA. The BMD and T-score values for the femoral neck and the total hip at QCT were lower compared to the values of the DXA results. Considering the conducted research, it is recommended that when introducing asynchronous QCT into clinical practice to identify people with osteoporosis, a synchronous phantom should be pre-scanned to compare the QCT and DXA results, followed by adjusting the BMD and T-score values for QCT by the average difference between them.

Purpose of the study — to assess the accuracy of dual energy x-ray absorptiometry (DXA ) for measurements of mineral bone density, bone mineral content, area of selected spine zone of examination as well as impact of subcutaneous fat layer and correction of auto-segmenting of the spine on the mentioned parameters. Material and Methods. The study was performed on iDXA scanner using the designed phantom DMA PP2 of the lumber spine with inlays to simulate subcutaneous fat (SF). To ensure correct assessment of measurements (precision and accuracy) the authors performed fivefold repeated scanning. Two modifications of the phantom were used, with and without SF inlays, as well as two methods for selection of spine range for examination – automatic and correction of autosegmentation. Results. Scanning of the phantom without SF inlays demonstrated a systematic understated values of bone mineral density (BMD) and bone mineral content (BMC) along the full measured interval: mean relative error of BMD for L1-L4 interval was 10.62% with automatic segmentation and 7.43% — with correction of autosegmentation. The least accuracy for BMD and BMC (1.53% and 0.90%, respectively) was observed during SF simulation and with correction of auto-segmentation of the spine. Analysis of variation coefficient for area of examined vertebrae, BMC and BMD demonstrated rather high precision of measurements, namely for BMD without SF in the L1-L4 interval amounted to 1.00% (auto-segmentation) and 0.56% (correction). Variation coefficient for scanning including SF inlays in the interval L1-L4 was 1.00% (auto-segmentation) and 0.68% (correction). Conclusion. The lowest level of accuracy was observed with the SFL object; in this case, the variation coefficient did not exceed 1% for all BMD interval. The mean value of the BMC accuracy also did not exceed 1% with the optimal scan parameters. The study proved the effectiveness of “RSK PK2” phantom when estimating the accuracy of BMD and BMC on iDXA scanner.