Authors: Charles X B Yan Benoît Goulet Sean JyShyang Chen Donatella Tampieri D Louis Collins
Publish Date: 2011/11/24
Volume: 7, Issue: 4, Pages: 601-610
Abstract
Imageguided spine surgery requires registration of the patient anatomy and preoperative computed tomography CT images A technique for intraoperative ultrasound image registration to preoperative CT scans was developed and tested Validation of the ultrasoundCT registration technique was performed using porcine cadaversAn ultrasoundCT registration technique was evaluated using 18 thoracic and lumbar vertebrae of 3 porcine cadavers with 10 different sweep patterns for ultrasound acquisition For each sweep pattern at each vertebra 100 randomly simulated initial misalignments were introduced Each misalignment was registered The resulting registration transformations were compared to gold standard registrations based on implanted fiducials to assess accuracy and robustness of the techniqueThe orthogonalsweep acquisition was found to perform best and yielded a registration accuracy of 165 mm across all vertebrae on all porcine cadavers where 825 of the registrations resulted in target registration errors below the 2 mm threshold recommended by a joint report from the experts in the field In addition we found that registration accuracy varies by the sweep pattern and vertebral level but neighboring vertebrae tend to result in statistically similar accuracy UltrasoundCT registration took an average of 25 min to run and the total registration time per vertebra also including time for ultrasound acquisition and reconstruction is approximately 8 minA previously described ultrasoundCT registration technique yields clinically acceptable accuracy and robustness on multiple vertebrae across multiple porcine cadavers The total registration time is shorter than that of surface pointbased manual registration
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