title: Clinical evaluation of a high-resolution new peripheral quantitative computerized tomography (pQCT) scanner for the bone densitometry at the lower limbs.
abstract: Precision, long-term stability, linearity and accuracy of the x-ray peripheral quantitative computerized tomographic (pQCT) bone scanner XCT 3000 (Norland-Stratec Medical Sys.) were evaluated using the European Forearm Phantom (EFP). In vivo measurements were assessed using a standardized procedure at the distal femur and the distal tibia. In the patient-scan mode, the spatial resolution of the system was 1.04 +/- 0.05 lp/mm as measured at the 10% level of the modulation transfer function (MTF). The contrast-detail diagram (CDD) yielded a minimal difference in attenuation coefficient (AC) of 0.07 cm(-1) at an object size of 0.5 mm. The effective dose for humans was calculated to be less than 1.5 microSv per scan. Short-term precision in vivo was expressed as root mean square standard deviation of paired measurements of 20 healthy volunteers (RMSSD = 0.5%). At the distal femur total volumetric density (ToD) and total cross-sectional area (ToA) were found to be less sensitive to positioning errors than at the distal tibia. Structural parameters like the polar cross-sectional moment of inertia (CSMIp) or the polar cross-sectional moment of resistance (CSMRp) showed a good short-term precision at the distal femur (RMSSD = 1.2 and 1.4%). The relation between the two skeletal sites with respect to CSMIp or CSMRp showed a high coefficient of determination (r2 = 0.77 and 0.74).
authors.affiliation: Clinic of Nuclear Medicine, University of Wuerzburg, Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Braun
authors.forename: M D
authors.initials: MD
authors.lastname: Meta
authors.forename: P
authors.initials: P
authors.lastname: Schneider
authors.forename: C
authors.initials: C
authors.lastname: Reiners
mesh_terms: D015519:Bone Density; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D019047:Phantoms, Imaging; D011785:Quality Assurance, Health Care; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012984:Software; D013977:Tibia / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods / Q000592:standards