Cortical and total bone mineral content of the radius: accuracy of peripheral computed tomography

The aim of the study was to evaluate the accuracy of an XCT 960 Stratec peripheral quantitative computed tomography (pQCT) device in assessing bone mineral content of the radius. We scanned 27 left forearm specimens excised from cadavers and focused on cortical bone mineral content (BMCc) at the junction of the middle and distal third and on total bone mineral content (BMCtot) at the distal end of the radius. Cylindrical specimens matched with those two sites were cut using a diamond circular saw, embedded in a polyester resin and subsequently submitted to two reference methods, nondestructive neutron activation analysis and flame atomic absorption spectrometry. Mineral contents measured by pQCT were closely correlated with those assessed by using the two reference methods, with correlation coefficients ranging from 0.862 to 0.960. The standard error of the estimate amounted 7-10% for the BMCc (junction of the middle and distal third), and 17-18% for the BMCtot (distal end). We conclude that pQCT is able to measure either cortical or total mineral content of the radius with a high degree of accuracy.