Establishing a method to measure bone structure using spectral CT

M. Ramyar, C. Leary, A. Raja, A. P.H. Butler, T. B.F. Woodfield, N. G. Anderson

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Combining bone structure and density measurement in 3D is required to assess site-specific fracture risk. Spectral molecular imaging can measure bone structure in relation to bone density by measuring macro and microstructure of bone in 3D. This study aimed to optimize spectral CT methodology to measure bone structure in excised bone samples. MARS CT with CdTe Medipix3RX detector was used in multiple energy bins to calibrate bone structure measurements. To calibrate thickness measurement, eight different thicknesses of Aluminium (Al) sheets were scanned one in air and the other around a falcon tube and then analysed. To test if trabecular thickness measurements differed depending on scan plane, a bone sample from sheep proximal tibia was scanned in two orthogonal directions. To assess the effect of air on thickness measurement, two parts of the same human femoral head were scanned in two conditions (in the air and in PBS). The results showed that the MARS scanner (with 90μm voxel size) is able to accurately measure the Al (in air) thicknesses over 200μm but it underestimates the thicknesses below 200μm because of partial volume effect in Al-air interface. The Al thickness measured in the highest energy bin is overestimated at Al-falcon tube interface. Bone scanning in two orthogonal directions gives the same trabecular thickness and air in the bone structure reduced measurement accuracy. We have established a bone structure assessment protocol on MARS scanner. The next step is to combine this with bone densitometry to assess bone strength.

Original languageBritish English
Title of host publicationMedical Imaging 2017
Subtitle of host publicationPhysics of Medical Imaging
EditorsTaly Gilat Schmidt, Joseph Y. Lo, Thomas G. Flohr
ISBN (Electronic)9781510607095
StatePublished - 2017
EventMedical Imaging 2017: Physics of Medical Imaging - Orlando, United States
Duration: 13 Feb 201716 Feb 2017

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
ISSN (Print)1605-7422


ConferenceMedical Imaging 2017: Physics of Medical Imaging
Country/TerritoryUnited States


  • Aluminium phantom
  • Bone strength
  • Bone structure assessment
  • Cortical thickness
  • Partial volume effect
  • Scan direction
  • Spectral CT
  • Trabecular thickness


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