[MRI-CT fusion image navigation during surgery for inverted papilloma]

We report two cases of intraoperative computer-aided surgery using magnetic resonance imaging (MRI)/computed tomography (CT) fusion imaging for inverted papilloma (IP). Case 1: IP had spread to the frontal recess/sinus so we chose a combined endoscopic sinus surgery (ESS) and external approach. Case 2: For a maxillary sinus tumor, we combined ESS and the adjuvant external (Caldwell-Luc) procedure. This is helpful to surgeons when, shifting fusion imaging when opening the frontal sinus bone to obtain CT data, and shifting to MRI to detect the tumor pedicle, then approaching the bone defect using MRI-CT fusion imaging (50-50%).