CARS 2013: Advanced Imaging Capability in Dedicated Cone-Beam CT of Musculoskeletal Extremities

John Yorkston, Ph.D., Senior Research Scientist, Carestream

John Yorkston, Ph.D., Senior Research Scientist, Carestream

At this year’s CARS conference, Carestream scientists will co-author a research paper with colleagues from Johns Hopkins University describing the results of an ongoing, multi-year research project to develop a cone beam CT system specifically optimized for extremity imaging (i.e. hand, wrist, knee, ankle and foot).

In the spirit of recent diagnostic imaging trends focused on low-dose imaging, the technical advances presented in the paper show:

  • High-quality x-ray scatter correction based on GPU-accelerated Monte Carlo (MC) models
  • Model-based iterative reconstruction for high-quality, low-dose imaging
  • Dual-energy (DE) imaging to extend contrast resolution beyond conventional limits
  • Quantitative imaging methods for accurate assessment of bone density, subchondral architecture, and joint space morphometry.

The presentation will focus on the excellent image quality obtained by this optimized system and the opportunity for “advanced” imaging applications such as dual energy CT that are enabled by the system design, as well as the results of implementing advanced algorithms, which includes iterative reconstruction and Monte Carlo scatter correction.  The resulting images demonstrate boney detail that is superior to that obtained from traditional diagnostic CT systems (DxCT) as well as soft tissue detail that is sufficient for many diagnostic tasks performed by DxCT.

The reconstruction algorithms have been implemented on a GPU platform that increases reconstruction speed by more than an order of magnitude from that obtained with a CPU implementation. Accurate quantitative analysis of the attenuation coefficients and geometric spacings of different anatomical structures hold the promise of enhancing the diagnostic and treatment response capabilities of the acquired data sets and are the subject of ongoing research funded by the NIH.

The results to be presented indicate that the customized system demonstrates a promising new technology for diagnosis, therapy planning, and treatment assessment in musculoskeletal radiology, orthopaedics, and rheumatology. Advanced imaging techniques – including high-quality MC scatter correction, iterative reconstruction, and DE imaging – may offer new capabilities in soft-tissue visualization and quantitative image analysis.

Below is the complete list of researchers who participated in this study:

J. H. Siewerdsen,a,b W. Zbijewski,a J. W. Stayman,a A. Muhit,a J. Yorkston,c and J. A. Carrinob

a Department of Biomedical Engineering, Johns Hopkins University, Baltimore MD

b Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore MD

c Carestream Health, Rochester NY