[Comparative measurements of bone mineral content using DPA and DPX--initial clinical experiences]

A technically satisfactory method with adequate precision and reproducibility is necessary for accurate determination of bone mineral content. To the previously described techniques (SPA, DPA, QCT and SQCT) a new method has been added based on the absorption of a filtered x-ray beam (DPX). Comparison of DPA/DPX measurements of the mineral contents of vertebrae and femora in 126 patients showed a high correlation between the results (r = 0.97 for vertebrae and 0.93 for femoral necks). Ten measurements of a vertebral phantom and ten measurements of a normal male showed significantly higher accuracy of the DPX method. Other advantages of the DPX method are increased speed of the procedure by a factor 3-5, lower radiation dose and better spatial resolution. Measurements of the upper and lower extremities are possible in addition to whole body scans. In summary, the DPX technique is a significant improvement on the conventional DPA method, whereas the data obtained from DPA measurements remain valid.