Intraoperative Integration of Multimodal Imaging to Improve Neuronavigation: A Technical Note.

Background: Brain shift may cause significant error in neuronavigation, leading the surgeon to possible mistakes. Intraoperative magnetic resonance imaging (MRI) is the most reliable technique in brain tumor surgery. Unfortunately, it is highly expensive and time consuming and, at the moment, it is available only in few neurosurgical centers.

Methods: In this case series the surgical workflow for brain tumor surgery is described where neuronavigation of preoperative MRI, intraoperative computed tomography (CT) scan, and ultrasound (US) as well as rigid and elastic image fusion between preoperative MRI and intraoperative US and CT, respectively, was applied to 4 brain tumor patients in order to compensate for surgically induced brain shift by using a commercially available software (Elements Image Fusion 4.0 with Virtual iMRI Cranial; Brainlab AG, München, Germany).

Results: Four illustrative cases demonstrated successful integration of different components of the described intraoperative surgical workflow. The data indicate that intraoperative navigation update is feasible by applying intraoperative 3-dimensional US and CT scanning as well as rigid and elastic image fusion applied depending on the degree of observed brain shift.

Conclusions: Integration of multiple intraoperative imaging techniques combined with rigid and elastic image fusion of preoperative MRI may reduce the risk of incorrect neuronavigation during brain tumor resection. Further studies are needed to confirm the present findings in a larger population.