Preliminary study evaluating the accuracy of MRI images on CBCT images in the field of orthodontics.

OBJECTIVE: The purpose of this study was to explore the 3-dimensional (3D) accuracy of magnetic resonance imaging (MRI) on cone-beam computed tomography (CBCT) images after the registration of MRI images on CBCT images. MATERIALS AND METHODS: Three Japanese adult females volunteered for this study. To transform digital imaging and communication in medicine (DICOM) data derived from MRI and CBCT images into polygon data, five software programs were used. CBCT and MRI images were obtained within one week, and both were registered by the iterative closest point (ICP) method. To assess the accuracy of the composite MRI-CBCT, the measurement errors of the MRI-CBCT were verified Measurement values were compared using frontal and cephalometric soft-tissue landmarks. Differences were analyzed using the non-parametric Mann-Whitney U test. RESULTS: There were no significant linear measurement errors (P > 0.05) when the images were measured from the superimposed MRI-CBCT images. CONCLUSION: The MRI images attained from MRI - CBCT registration showed accurate 3D linear measurements.