Evaluation of BoneMRI for surgical spine planning and navigation

Abstract

Purpose: To qualitatively evaluate the performance of BoneMRI —a synthetic Computed Tomography (CT) scan— for surgical planning and navigation in the spine and to determine the potential added value of BoneMRI compared to an isotropic 3D T1 Magnetic Resonance (MR) sequence. Materials and methods: In this study patients who received dorsal stabilisation using a screw and rod system on the lumbar or sacral spine were included. For each patient an MRI was performed, including an isotropic 3D T1 MR, and synthetic CT images were reconstructed from a T1-weighted multiple gradient-echo scan using the BoneMRI software. Surgical planning of the screws was performed. BoneMRI was evaluated by three observers, through a questionnaire and with results following a likert scale, on the visualisation of anatomical structures, the confidence during preoperative planning and the added value during planning. The obtained scores were examined by means of a contingency table; the interrater reliability was examined with the intraclass correlation coefficient; and statistical tests were calculated to study the possibility of correlation between different variables. Results and Discussion: 24 patients were included in the study and in total 110 screws were placed in the lumbar and S1 vertebrae. BoneMRI showed adequate visualisation of anatomical regions in 90% of all scored vertebrae and good to excellent interrater reliability between the three observers was found (ICC: 0.85 to 0.96). BoneMRI showed to be capable to perform screw planning with confidence, was capable to visualise pathologies and showed to be an added value compared to the isotropic 3D T1 MR scan. Conclusion: BoneMRI produces adequate qualitative image quality and showed an added value for surgical planning in the spine.