title: Optimizing results from pQCT: reliability of operator-dependent pQCT variables in cadavers and humans with low bone mass.
abstract: Peripheral quantitative computed tomography (pQCT) can assess bone geometric properties and separate cortical from trabecular bone. Despite pQCT's potential benefits for research, most reliability and accuracy studies have used a constant acquisition and analysis protocol. There are, however, numerous steps in the pQCT scan acquisition and analysis that are operator dependent. Whether or not these influence the quality of the pQCT scans and, potentially, the precision and validity of the data collected has been little explored. We investigated how pQCT outputs changed when operator-dependent parameters were varied, particularly when the bone of interest was of low mineral density. We found that bone parameters and scan failure rate varied significantly depending on the acquisition resolution; only one scan slice at the 10 and 30% radius is required to maintain adequate precision, and reference lines for sites should use a reproducible landmark. These results provide a foundation for recommending scan acquisition and analysis options for patients with low bone mass.
authors.affiliation: Department of Orthopaedics, University of British Columbia, and British Columbia Women's and Children's Hospital, BC, Canada.
authors.forename: Maureen C
authors.initials: MC
authors.lastname: Ashe
authors.forename: Teresa
authors.initials: T
authors.lastname: Liu-Ambrose
authors.forename: Karim M
authors.initials: KM
authors.lastname: Khan
authors.forename: Neil
authors.initials: N
authors.lastname: White
authors.forename: Heather A
authors.initials: HA
authors.lastname: McKay
mesh_terms: D000368:Aged; D015519:Bone Density; D002102:Cadaver; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D066298:In Vitro Techniques; D015588:Observer Variation; D010024:Osteoporosis / Q000000981:diagnostic imaging*; D011884:Radius / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000592:standards*