Utilizing “Black Bone” MRI in Craniofacial Virtual Surgical Planning: A Comparative Cadaver Study

Background: The use of MRI for virtual surgical planning has not yet been described. In the US, over 600,000 CT scans are performed on children annually, who are at higher risk for developing cancer caused by ionizing radiation compared to adults. The aim of this study is to demonstrate that 3D printed craniofacial surgical guides created from Black Bone MRI are comparable in accuracy to those created from CT scans. Methods: A mock craniosynostosis surgery translocating four calvarial segments was virtually planned and performed in ten cadavers. For five specimens, this planning was performed and 3D-printed guides created using Black Bone MRI scans. Five other specimens underwent standard planning using CT scans. The reconstructed skulls underwent CT scans and 3D-reconstruction. Surgical accuracy was then compared to the virtually-planned surgery. Results: The pre-op Black Bone MRI scan had an average deviation from the pre-op CT scan of 1.37mm. There was no statistically significant difference in the accuracy of guide fit between MRI versus CT-created guides. Average deviation of post-operative anatomy from pre-operative plan was within 1.5mm for both MRI and CT-created guides, with no statistically significant difference in accuracy between the two methods. Planned versus postoperative skull volume was not statistically significant different when MRI versus CT was used. Conclusion: This study demonstrates that virtual surgical planning and 3D surgical guide creation for craniofacial surgery can be performed using Black Bone MRI with comparable accuracy to CT scans. This could dramatically reduce radiation exposure for pediatric and adult craniofacial reconstruction patients. Financial Disclosure Statement: There are no financial disclosures to report. Presented at: Mayo Clinic Chang Gung Symposium in Reconstructive Surgery, Munich, Germany, October 21, 2016 Acknowledgments: This work supported by a generous gift from the Tribuno Family. We would like to thank Kyle Iverson from Mayo Clinic for help with MRI scanning, and Shelby Marks, Cyndi Hoffmeister, and Katie Weimer from 3D Systems for their support and help with scan analysis, segmentation, guide design, and postoperative analysis. We would like to acknowledge the Mayo Clinic Anatomy Department, especially Shaun Heath, Karen Mills, Andy Wilhorn, and Terry Regnier, as well as the noble generosity of the Mayo Clinic's whole body donors whose altruistic gift made this study possible. Corresponding author: Samir Mardini, MD, Professor of Surgery, Mayo Clinic College of Medicine, Program Director, Plastic Surgery, Mayo Clinic, Rochester, MN, Email: mardini.samir@mayo.edu ©2018American Society of Plastic Surgeons

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