Share Email Print
cover

Proceedings Paper

Design and optimization of a dedicated cone-beam CT system for musculoskeletal extremities imaging
Author(s): W. Zbijewski; P. De Jean; P. Prakash; Y. Ding; J. W. Stayman; N. Packard; R. Senn; D. Yang; J. Yorkston; A. Machado; J. A. Carrino; J. H. Siewerdsen
Format Member Price Non-Member Price
PDF $17.00 $21.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

The design, initial imaging performance, and model-based optimization of a dedicated cone-beam CT (CBCT) scanner for musculoskeletal extremities is presented. The system offers a compact scanner that complements conventional CT and MR by providing sub-mm isotropic spatial resolution, the ability to image weight-bearing extremities, and the capability for integrated real-time fluoroscopy and digital radiography. The scanner employs a flat-panel detector and a fixed anode x-ray source and has a field of view of ~ (20x20x20) cm3. The gantry allows a "standing" configuration for imaging of weight-bearing lower extremities and a "sitting" configuration for imaging of upper extremities and unloaded lower extremities. Cascaded systems analysis guided the selection of x-ray technique (e.g., kVp, filtration, and dose) and system design (e.g., magnification factor), yielding input-quantum-limited performance at detector signal of 100 times the electronic noise, while maintaining patient dose below 5 mGy (a factor of ~2-3 less than conventional CT). A magnification of 1.3 optimized tradeoffs between source and detector blur for a 0.5 mm focal spot. A custom antiscatter grid demonstrated significant reduction of artifacts without loss of contrast-to-noise ratio or increase in dose. Image quality in cadaveric specimens was assessed on a CBCT bench, demonstrating exquisite bone detail, visualization of intra-articular morphology, and soft-tissue visibility approaching that of diagnostic CT. The capability to image loaded extremities and conduct multi-modality CBCT/fluoroscopy with improved workflow compared to whole-body CT could be of value in a broad spectrum of applications, including orthopaedics, rheumatology, surgical planning, and treatment assessment. A clinical prototype has been constructed for deployment in pilot study trials.

Paper Details

Date Published: 15 March 2011
PDF: 8 pages
Proc. SPIE 7961, Medical Imaging 2011: Physics of Medical Imaging, 796104 (15 March 2011); doi: 10.1117/12.878077
Show Author Affiliations
W. Zbijewski, The Johns Hopkins Univ. (United States)
P. De Jean, The Johns Hopkins Univ. (United States)
P. Prakash, The Johns Hopkins Univ. (United States)
Y. Ding, The Johns Hopkins Univ. (United States)
J. W. Stayman, The Johns Hopkins Univ. (United States)
N. Packard, Carestream Health, Inc. (United States)
R. Senn, Carestream Health, Inc. (United States)
D. Yang, Carestream Health, Inc. (United States)
J. Yorkston, Carestream Health, Inc. (United States)
A. Machado, The Johns Hopkins Univ. (United States)
J. A. Carrino, The Johns Hopkins Univ. (United States)
J. H. Siewerdsen, The Johns Hopkins Univ. (United States)


Published in SPIE Proceedings Vol. 7961:
Medical Imaging 2011: Physics of Medical Imaging
Norbert J. Pelc; Ehsan Samei; Robert M. Nishikawa, Editor(s)

© SPIE. Terms of Use
Back to Top