Determination of bone structural parameters from multiple projection DXA images

T. S. Spisz, T. J. Beck, H. S. Feldmesser, M. H. Chen, T. C. Magee, Paul R. Bade, H. K. Charles

Research output: Contribution to journalConference articlepeer-review

2 Scopus citations


To more precisely measure and monitor bone health, The Johns Hopkins University Applied Physics Lab and School of Medicine have developed the Advanced Multiple Projection Dual-Energy X-Ray Absorptiometry (AMPDXA) scanner. This system provides improvements over conventional DXA scanners in image resolution and multiple projection capability. These improvements allow us to determine structural information about the bone in addition to the standard bone mineral density (BMD) measurements. Algorithms and software were developed to process data acquired from the AMPDXA scanner and to determine important structural parameters, such as the center of mass axis in three dimensions and cross-sectional moments of inertia. The analysis operates on three projections about 15 degrees apart, calculates BMD for each projection, and then combines the data into a three dimensional coordinate system. By knowing the patient position in three dimensions, bone structural parameters are calculated more precisely. Using repeated testing of cadaver bones, the precision of determining these structural parameters is approximately the detector pixel size of 0.127 mm. Data on artificial bone cylinders indicate accuracy of about 3%. Comparisons between bone structural parameters derived from AMPDXA and CT scans show very similar results.

Original languageEnglish (US)
Pages (from-to)730-741
Number of pages12
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - Jul 5 2004
EventMedical Imaging 2004: Physiology, Function, and Structure from Medical Images - San Diego, CA, United States
Duration: Feb 15 2004Feb 17 2004


  • Bone mass density
  • Center of mass
  • Dual x-ray absorptiometry
  • Image processing
  • Microgravity-induced bone loss
  • Osteoporosis

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Determination of bone structural parameters from multiple projection DXA images'. Together they form a unique fingerprint.

Cite this