Functional Magnetic Resonance Imaging and Diffusion Tensor Imaging for Language Mapping in Brain Tumor Surgery:...

Area of Science:

• Neuroimaging
• Neurosurgery
• Language Mapping

Background:

• Accurate localization of language areas is crucial for neurosurgical planning.
• Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging-derived tractography (DTI-t) are advanced neuroimaging techniques used for this purpose.
• However, their diagnostic performance for mapping critical language areas like Broca's area remains a subject of investigation.

Purpose of the Study:

• To evaluate the diagnostic accuracy of preoperative fMRI and DTI-t in mapping Broca's area.
• To compare the performance of these techniques against intraoperative direct cortical stimulation (DCS) and corticocortical evoked potentials (CCEP).

Main Methods:

• A prospective study involving 26 patients with tumors near Broca's area.
• Preoperative fMRI and DTI-t were acquired using a simultaneous multi-slice technique.
• A site-by-site comparison of 226 cortical sites was conducted between preoperative imaging and intraoperative language mapping (DCS or CCEP).

Main Results:

• fMRI and DTI-t demonstrated high specificity (up to 96.8%) when compared to intraoperative standards.
• Sensitivity varied: fMRI (69.2%-92.3%) and DTI-t (40.0% or lower) showed good performance with DCS but were less sensitive with CCEP.
• Concordant positive signals on both fMRI and DTI-t yielded a high true-positive rate (81.2%-100%).

Conclusions:

• Preoperative fMRI and DTI-t are sensitive and specific for mapping Broca's area, particularly when compared with DCS.
• A positive signal on both fMRI and DTI-t strongly suggests an essential language area, enhancing surgical planning.
• These findings support the utility of combined fMRI and DTI-t for precise language area localization in neurosurgery.