Computerized Bone Densitometric Analysis: Operator-dependent Errors

Abstract

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.

Bone imaging: Traditional techniques and their interpretation

“…Still, generally speaking, densitometry of the hip has a lower precision than densitometry of the spine (eg, AP) [31,32].…”

Artifacts and Incidental Findings Encountered on Dual-Energy X-Ray Absorptiometry: Atlas and Analysis

“…In the spine, the types of error that most commonly occur include misidentification of vertebral end plates, miscategorization of opaque artifacts as bone, oversizing of ROIs, and mislabeling of vertebrae. 127 This latter error is likely related to the fact that 15% of the population has four or six lumbar vertebrae, with the last pair of ribs on T11 or L1. 128 Another potential source of error is incorrectly assigning the race and sex of a patient undergoing DEXA, 129 which can result in artifactually increased or decreased Z scores.…”

Reproducibility of DXA: Potential Impact on Serial Measurements and Misclassification of Osteoporosis

“…where S 2 instr , S 2 subj , S 2 oper and S 2 interact represent respectively the instrument (within-and between-day), subject (body fat, anatomic characteristics, movement during scan), operator (scan setup, scan analysis, subject positioning and re-positioning) [5] and interaction (mainly operator-subject) components of variance. For a DXA qc, like the spine phantom, S 2 A = S 2 instr , however, in vitro S 2 instr is not equivalent to in vivo S 2 instr .…”