Femur BMD Bias Associated with DPX-IQ Reanalysis of DPX-Acquired Scan Files

Bone mineral density values calculated by DPX-IQ software reanalysis of original DPX software analyzed scans were compared at the femur region. Based on the results for 24 subjects each scanned on 12 different occasions, a significant bias at all sites – neck, Ward’s triangle and trochanter – ranging from −0.7% (neck) to −2.1% (trochanter) was found. For the trochanter site 16 of the 24 subjects had significantly lower mean BMD values after DPX-IQ reanalysis, a trend also noted at the neck and Ward’s triangle. Although it has been recommended that scans analyzed with DPX software do not require DPX-IQ reanalysis, our findings strongly indicate that DPX-IQ reanalysis is essential to minimize total error during follow-up BMD determinations. Received: 9 April 1999 / Accepted: 20 July 1999