Small animal DXA instrument comparison and validation

Jennifer C Coulombe; David E Maridas; Jarred L Chow; Mary L Bouxsein

doi:10.1016/j.bone.2023.116923

Small animal DXA instrument comparison and validation

Bone. 2024 Jan:178:116923. doi: 10.1016/j.bone.2023.116923. Epub 2023 Sep 29.

Authors

Jennifer C Coulombe¹, David E Maridas², Jarred L Chow³, Mary L Bouxsein⁴

Affiliations

¹ Center for Advanced Orthopedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, United States of America; Harvard Medical School, Boston, MA, United States of America.
² Harvard Dental School, Boston, MA, United States of America.
³ Center for Advanced Orthopedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, United States of America.
⁴ Center for Advanced Orthopedic Studies, Department of Orthopedic Surgery, Beth Israel Deaconess Medical Center, Boston, MA, United States of America; Harvard Medical School, Boston, MA, United States of America. Electronic address: mbouxsei@bidmc.harvard.edu.

PMID: 37778596
DOI: 10.1016/j.bone.2023.116923

Abstract

Several new peripheral dual-energy X-ray absorptiometry (DXA) devices designed for assessment of bone and body composition in rodents have been developed. We compared the performance (accuracy and precision) of two of these devices, the InAlyzer and the iNSiGHT, to those of an established device, the PIXImus. We measured total body bone mineral content (BMC), bone mineral density (BMD), and body composition (lean and fat mass) on the three DXA devices in 18 male C57Bl/6 J mice (6 each of ages 8, 14, and 24 weeks, weighing 22 to 33 g). DXA body composition measures were compared to whole-body nuclear magnetic resonance (NMR) outcomes. BMC of the femur was also compared to ex vivo micro-computed tomography (microCT). Total body BMD from the InAlyzer and iNSiGHT devices was strongly correlated to that from PIXImus (R² = 0.83 and 0.82, respectively), but was ~25 % higher than PIXImus. Total body BMC measures by InAlyzer were strongly associated with those from PIXImus (R² = 0.86), whereas those from iNSiGHT were only weakly correlated (R² = 0.29). Femur BMC from InAlyzer was strongly correlated with microCT outcomes, whereas iNSiGHT was only weakly correlated. InAlyzer and iNSiGHT fat mass measures were very strongly correlated with PIXImus and NMR outcomes (R² = 0.91 to 0.97), with slightly weaker associations for lean mass (R² = 0.81 to 0.76). Short-term precision of InAlyzer and iNSiGHT measurements were excellent, and akin to those from the PIXImus for both body composition and bone measures, ranging between 0.39 and 3.2 %. With faster scan times, closed X-ray source and excellent precision, the new devices are both satisfactory replacements for the now discontinued PIXImus system. However, given the accuracy of the bone and body composition measures, the InAlyzer may be preferable for studies where musculoskeletal changes are the main interest.

Keywords: BMC; BMD; Body composition; DXA; Fat mass; InAlyzer; Lean mass; Murine model; NMR; PIXImus; Validation; iNSight; microCT.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Absorptiometry, Photon / methods
Animals
Body Composition
Bone Density*
Bone and Bones*
Male
Mice
Mice, Inbred C57BL
Radiography
X-Ray Microtomography