title: Assessment of trabecular bone microarchitecture by two different x-ray microcomputed tomographs: a comparative study of the rat distal tibia using Skyscan and Scanco devices.
abstract: Important aspects of modern skeletal research depend on the phenotypical characterization of trabecular bone microarchitecture as assessed by microcomputed tomography (micro-CT). Until now, however, there have been no studies which compare the two most commonly utilized micro-CT devices, namely, Skyscan and Scanco. The purpose of the current study was to examine the reproducibility and accuracy of these two micro-CT devices in comparison to traditional histomorphometry in ovariectomized rats treated with either propranolol, salbutamol, or vehicle. 6 month old female Wistar rats were ovariectomized (n = 48) or sham operated (n = 12). OVX rats were divided into four groups and then subcutaneously injected with propranolol 0.1 mg/kg/day, propranolol 20 mg/kg/day, salbutamol 3 mg/kg/day, or vehicle for 10 weeks. At sacrifice, the left tibial trabecular bone microarchitecture was analyzed using both the micro-CT Skyscan 1072 (ex vivo) and Scanco vivaCT40 (in vivo). Histomorphometric analysis was performed on the right proximal tibia. Comparisons between the different methods were performed using regression analysis, Bland-Altman, Passing-Bablock, and Mountain plots. Correlations were highly significant for all parameters measured between the two micro-CT instruments and were less significant between histomorphometry and micro-CT measurements taken from either the Skyscan or Scanco apparatus. Micro-CT overestimated bone volume compared to histomorphometry. In the ovariectomized rat model, the two micro-CT instruments revealed the same difference between groups whereas histomorphometry revealed only the difference which displayed the largest disparity between groups. In regards to the comparison between the two micro-CT devices, Mountain plot methods indicated that BV/TV, BS/BV, and TbSp were equivalent, whereas a systematic bias was observed for TbN and TbTh. The authors were also able to describe the routine method used to determine the threshold between the two micro-CT devices, which may help explain these differences. While some minor differences in the absolute values of the morphometry parameters exist between the micro-CT measurements from the Skyscan and Scanco instruments, both of these devices display a high degree of accuracy and reproducibility.
authors.affiliation: INSERM U658 CTI (Caracterisation du Tissu Osseux par Imagerie, Techniques et Applications), Orleans Regional Hospital and University of Orleans, Orleans F-45000, France. nicolas.bonnet15@orange.fr
authors.forename: N
authors.initials: N
authors.lastname: Bonnet
authors.forename: N
authors.initials: N
authors.lastname: Laroche
authors.forename: L
authors.initials: L
authors.lastname: Vico
authors.forename: E
authors.initials: E
authors.lastname: Dolleans
authors.forename: D
authors.initials: D
authors.lastname: Courteix
authors.forename: C L
authors.initials: CL
authors.lastname: Benhamou
mesh_terms: D000420:Albuterol / Q000494:pharmacology; D000465:Algorithms; D000818:Animals; D015519:Bone Density; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology; D005260:Female; D015233:Models, Statistical; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D012044:Regression Analysis; D015203:Reproducibility of Results; D013977:Tibia / Q000000981:diagnostic imaging* / Q000473:pathology*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*; D055114:X-Ray Microtomography / Q000295:instrumentation* / Q000379:methods*
chemical_list: D011433:Propranolol; D000420:Albuterol