Novel anthropomorphic hip phantom corrects systemic interscanner differences in proximal femoral vBMD

S. Bonaretti, R. D. Carpenter, I. Saeed, A. J. Burghardt, Lifeng Yu, M. Bruesewitz, Sundeep Khosla, T. Lang

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Quantitative computed tomography (QCT) is increasingly used in osteoporosis studies to assess volumetric bone mineral density (vBMD), bone quality and strength. However, QCT is confronted by technical issues in the clinical research setting, such as potentially confounding effects of body size on vBMD measurements and lack of standard approaches to scanner cross-calibration, which affects measurements of vBMD in multicenter settings. In this study, we addressed systematic inter-scanner differences and subject-dependent body size errors using a novel anthropomorphic hip phantom, containing a calibration hip to estimate correction equations, and a contralateral test hip to assess the quality of the correction. We scanned this phantom on four different scanners and we applied phantom-derived corrections to in vivo images of 16 postmenopausal women scanned on two scanners. From the phantom study, we found that vBMD decreased with increasing phantom size in three of four scanners and that inter-scanner variations increased with increasing phantom size. In the in vivo study, we observed that inter-scanner corrections reduced systematic inter-scanner mean vBMD differences but that the inter-scanner precision error was still larger than expected from known intra-scanner precision measurements. In conclusion, inter-scanner corrections and body size influence should be considered when measuring vBMD from QCT images.

Original languageEnglish (US)
Pages (from-to)7819-7834
Number of pages16
JournalPhysics in Medicine and Biology
Volume59
Issue number24
DOIs
StatePublished - Dec 21 2014

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Keywords

  • anthropomorphic hip phantom
  • body size
  • bone mineral density
  • inter-scanner differences
  • quantitative computed tomography

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Radiological and Ultrasound Technology

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