Computerized bone densitometric analysis: operator-dependent errors.

Abstract

To determine the nature and relative frequency of operator-dependent data analysis errors in dual x-ray absorptiometry. Over 40 months, 2,528 dual x-ray absorptiometric examinations of the forearm, femoral neck, and lumbar spine were performed by 11 technologists by using standard techniques and software. Each analysis was reviewed by a radiologist; errors were recorded and corrected. There were no forearm analysis errors. There were 24 (0.9%) femoral neck analysis errors, of which 23 resulted from misplacement of the analysis region. There were 33 (1.3%) spinal analysis errors, of which 24 resulted from misplacement of intervertebral disk space markers. Analysis errors of the femur and spine resulted in six misdiagnoses (0.2%). Misdiagnosis due to analysis errors is rare. Femoral neck analysis errors were easily detectable, but accurate spinal analyses depended on accurate identification of vertebral end plates and posterior elements. Nonetheless, these potentially serious errors can be detected and corrected if the analyses are reviewed and interpreted by a supervising physician who is familiar with the relevant anatomy, proper analysis techniques, and factors--such as artifacts--that adversely affect the accuracy of the analysis.