Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5032315 | Journal of Biomechanics | 2016 | 7 Pages |
Abstract
Comprehensive assessments of scoliotic deformity and spinal instability require repetitive three-dimensional (3D) measurements of motion segments at different functional postures. However, accurate 3D measurement of the spine is a challenging task. In this paper, we present a novel, non-invasive, non-ionizing technique to quantify 3D poses of lumbar motion segments in terms of clinically meaningful anatomical coordinates. The technique used ultra-short echo time (UTE) magnetic resonance (MR) images to construct subject-specific geometrical models of individual vertebrae and registered them with 3D ultrasound dataset acquired during pose measurements. A hierarchical registration approach was used to minimize the detrimental effects of speckle noise and artifacts within soft tissues on registration accuracy. The technique was validated using a human dry bone specimen as well as a fresh porcine cadaver. Registration errors were determined by comparing with a gold standard fiducial-based registration. Results showed that the technique is accurate and reliable with bias in sub-degree and sub-millimeter level (except for the flexion-extension of the porcine cadaver experiment, which was â1.74°), and average precision of 1.11° in rotation and 0.86 mm in position for the human dry bone experiment, and 1.26° and 1.23 mm for the porcine cadaver experiment. Given its non-ionizing nature, the UTE MR-ultrasound registration technique is particularly useful for repeated measurements and longitudinal follow-up. With further refinement and validation, it could be a powerful tool for 3D spinal assessment.
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Authors
Terry K. Koo, Wingchi Edmund Kwok,