Program Information
Assessment of a Novel Real-Time Cone Beam Tomosynthesis (CBT) X-Ray Scanner
C Atria1 , F Noo2 , J Keiriz1 , L Last1*, N Packard1 , (1) nView medical, inc., Salt Lake City, UTAH, (2) University of Utah, Salt Lake City, UT
Presentations
SU-K-601-3 (Sunday, July 30, 2017) 4:00 PM - 6:00 PM Room: 601
Purpose: To assess the image quality (IQ) of a novel Cone Beam Tomosynthesis (CBT) x-ray scanner that provides high resolution near-real-time 3D motion images to improve surgical accuracy, reduce radiation and reduce procedure time. A user observer test based on synthetic projection images was performed to compare the adequacy of this novel CBT method, Cone Beam Computed Tomography (CBCT), and fluoroscopy, the standard of care, for the task of placing pedicle screws.
Methods: Four practicing surgeons made a total of 480 observations over 20 simulated surgical scenes, three imaging modalities, making two assessments per scene. Scene variability was obtained by randomly varying the position and orientation of a virtual pedicle screw in Monte Carlo realizations around a nominal placement. The same scenes were then used to simulate the novel CBT method, CBCT and fluoroscopy. Each surgeon performed the observations in randomized runs. Surgeons performed a binary classification based on whether or not they observed the screw breaching the cortical bone.
Results: Observer’s accuracy was 96% for CBT, 90% for CBCT and 83% for fluoroscopy. Paired Χ² McNemar's test showed that the sample size was sufficient to prove that the difference between the methods was statistically significant (p<0.05).
Conclusion: Observer tests based on simulated projection images show that the novel CBT method leads to superior accuracy than fluoroscopy and CBCT when observing pedicle screw placements. An analysis of the inaccurate observations shows that CBCT and CBT are superior to fluoroscopy because they provide 3D information. The novel CBT method outperforms CBCT due to the addition of the time dimension and because of a layered reconstruction approach that minimizes metal artifacts. Observer tests on actual reconstructions are needed to conclude on the benefits of CBT.
Funding Support, Disclosures, and Conflict of Interest: This research is funded through NSF SBIR Phase 1 award # 1345401 and nView medical, inc.
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