Pre-Operative Functional Mapping in Patients with Brain Tumors by fMRI and MEG: Advantages and Disadvantages in the Use of One Technique over the Other

Abstract

Pre-operative mapping of brain functions is crucial to plan neurosurgery and investigate potential plasticity processes. Due to its availability, functional magnetic resonance imaging (fMRI) is widely used for this purpose; on the other hand, the demanding cost and maintenance limit the use of magnetoencephalography (MEG), despite several studies reporting its accuracy in localizing brain functions of interest in patient populations. In this review paper, we discuss the strengths and weaknesses of both techniques, from a methodological perspective first; then, we scrutinized and commented on the findings from 16 studies, identified by a database search, that made pre-operative assessments using both techniques in patients with brain tumors. We commented on the results by accounting for study limitations associated with small sample sizes and variability in the used tasks. Overall, we found that, although some studies reported the superiority for MEG, the majority of them underlined the complementary use of these techniques and suggested assessment using both. Indeed, both fMRI and MEG present some disadvantages, although the development of novel devices and processing procedures has enabled ever more accurate assessments. In particular, the development of new, more feasible MEG devices will allow widespread availability of this technique and its routinely combined use with fMRI.

From bench to bedside: Overview of magnetoencephalography in basic principle, signal processing, source localization and clinical applications

“…The benefits of MEG + are as follows: (1) The combination of MEG and fMRI leverages the strengths of both modalities to overcome their individual limitations owing to the high temporal resolution of MEG and the high spatial resolution of fMRI ( Cargnelutti and Tomasino, 2023 ). (2) The combination of MEG and EEG can provide comprehensive information on the electromagnetic activity of the brain by using the sensitivity of MEG to deep sources of this activity and the high temporal resolution of EEG ( Heitmann et al, 2023 ).…”

Blockchain-Based Deep CNN for Brain Tumor Prediction Using MRI Scans

“…The proper diagnosis of brain tumors can be complicated and challenging due to several potential interfering factors. The industry-recognized imaging method for use in the diagnosis of brain tumors is magnetic resonance imaging (MRI) [ 17 ]. Image anomalies, however, can result from a variety of factors, such as patient motion, metallic implants, and other technological issues.…”