The introduction of new devices demands the assessment of their capabilities in established terms. The accuracy, reproducibility and spatial resolution of in vitro (phantom) osteodensitometric and morphometric measurements of QDR 2000 Plus and EXPERT are presented. Design details of these DXA/MXA-devices are listed and discussed in combination with the data acquired in the test measurements and calculations. The image quality will improve with further software developments. The long-term reproducibility and in vivo reliability remains to be evaluated.