Using Black Bone Magnetic Resonance Imaging in Craniofacial Virtual Surgical Planning: A Comparative Cadaver Study.

Background: The use of magnetic resonance imaging (MRI) for virtual surgical planning has not yet been described. In the United States, over 600,000 computed tomographic (CT) scans are performed annually on children, who are at higher risk than adults of developing cancer caused by ionizing radiation. The aim of this study was to demonstrate whether three-dimensionally-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 10 cadavers. For five specimens, planning was performed and three-dimensionally-printed guides were created using black bone MRI scans. Five specimens underwent standard planning using CT scans. Reconstructed skulls underwent CT scans and three-dimensional reconstruction. Accuracy was compared to that of virtually planned surgeries.

Results: The preoperative black bone MRI scan had an average deviation from the preoperative CT scan of 1.37 mm. There was no statistically significant difference in the fit accuracy of MRI versus CT-created guides. Average deviation of postoperative anatomy from preoperative plan was within 1.5 mm for guides created from either scanning modality, with no statistically significant difference in accuracy between the two methods. Planned versus postoperative skull volume was not statistically significantly different when MRI versus CT was used.

Conclusions: This study demonstrates that virtual surgical planning and three-dimensional craniofacial surgical guide creation can be performed using black bone MRI with accuracy comparable to that of CT. This could dramatically reduce radiation exposure of craniofacial reconstruction patients.