A comparison of calcaneal dual-energy X-ray absorptiometry and calcaneal ultrasound for predicting the diagnosis of osteoporosis from hip and spine bone densitometry.

Peripheral densitometry is increasingly being used in the management of osteoporosis, but the optimal diagnostic thresholds have not been defined. The aim of this study was to determine the optimal T-score for peripheral dual-energy X-ray absorptiometry (pDXA) of the heel using a GE Lunar PIXI and quantitative ultrasound (QUS) of the heel using a GE Lunar Achilles Plus when compared with dual-energy X-ray absorptiometry (DXA) of central sites (spine, femoral neck, or total hip). Ninety-nine women (mean age 69 +/- 8, range 33-86 yr) referred from the metabolic bone clinic were studied. The optimal T-score for pDXA from ROC analysis was -1.7 and for QUS was -2.5. The pDXA T-score that defined the same prevalence of osteoporosis at any central site was also -1.7 and for QUS was -2.4. These results are similar to the manufacturer's recommendations. There is no significant difference in performance between the PIXI and QUS.