Universal Standardization of Forearm Bone Densitometry

Abstract

As part of an effort to quantify device-dependent differences in forearm bone density, 101 women, aged 20 -80 years (ϳ16 women in each age decade), were scanned on six forearm bone densitometers: the Aloka DCS-600EX, the Hologic QDR-4500A, the Lunar PIXI, the Norland pDEXA, the Osteometer DTX-200, and the Pronosco X-posure System. Regression statistics are reported for all similar regions of interest (ROIs). However, comparisons were confounded because of large differences in the ROI size and placement. The number of ROIs reported for a single scan by each device varied from 1 to 12. The correlation coefficients ranged from 0.7 < r < 0.97, with the highest correlation coefficients and lowest SEs for comparisons between the most similar ROIs. Standardized units of bone mineral density are derived for distal (sdBMD), mid-(smBMD), and proximal (spBMD) ROIs that allow for comparable mean bone densities to be derived for patient populations. Five phantoms were scanned and characterized on five of the devices and the precision and mean values were reported. These phantom values will aid in the in vitro cross-calibration between manufacturers to recreate the presented in vivo relationships. Care should be exercised when using these equations for cross-calibrating patient databases or pooling clinical data from different devices because the least significant differences detectable from measurements taken on two different machines can be increased substantially. (J Bone Miner Res 2002;17:734 -745)

Bone Mineral Density Measured by a Portable X-ray Device Agrees With Dual-Energy X-ray Absorptiometry at Forearm in Preschool Aged Children

“…This concurs with our Bland-Altman, cross-classification analysis and kappa statistics, which all demonstrated that the PIXI BMD was in greatest agreement with the DXA UD forearm BMD. These results in young children are similar to previous results in adults, which demonstrated agreement between PIXI and DXA forearm BMD (12).…”

A multinational study to develop universal standardization of whole-body bone density and composition using GE Healthcare Lunar and Hologic DXA systems

“…Our comparison used a diverse population of pediatric and adults, males and females, with mixed ethnicities, and two clinical sites. Previous universal standardization studies (1,11,15) were performed using one densitometry system from each manufacturer and for only women.…”

Low bone mineral density at femoral neck is a predictor of increased mortality in elderly Japanese women

“…As a result, the final sample size was 57.4% (271/ 472), and the present findings may not be applicable to frail older people who have low physical functional capacity where BMD at the hip could not be measured in the prone position. Second, BMD has been measured at virtually all available measurement sites (spine, proximal femur, forearm, whole body, calcaneus, and tibia) [40,41]. In the present study, only the proximal femur, i.e., the femoral neck and trochanter regions, was used as an indicator of all-cause mortality.…”