Reliability of fMRI Language Mapping Paradigms

Abstract

Introduction

While the excision of a brain tumor is an inherently challenging procedure, one notable concern is whether language function will remain unimpaired following surgery. This is an important consideration, as the loss of linguistic ability can have a profound, negative impact on quality of life. Language mapping with functional Magnetic Resonance Imaging (fMRI) is a technique used to localize eloquent language cortex and verify hemispheric language dominance. This method is used regularly for preoperative planning to 1) determine the risks and benefits of surgery, 2) guide intra-operative cortical stimulation during awake craniotomy, and 3) supply patient-specific information about the location of language-critical areas to avoid during resection to maximize post-operative language function [1]. 

Language mapping paradigms are not currently standardized and may vary across clinics. Despite this variation, it is common practice to use a combination of expressive, receptive, and/or semantic linguistic tasks to ensure activation throughout the entire language network, thereby producing comprehensive language maps [2]. Reliability is a critical metric in assessing the validity of a language mapping paradigm for clinical applications. The present study will examine the intrasubject reliability of four paradigms in healthy participants in order to evaluate their usefulness in clinical applications.

Methods

Twenty right-handed native German speakers will participate in four fMRI measurements over three weeks. Participants will be asked to perform visual and auditory semantic decisions, name two objects, and decide if auditorily-presented sentences contain semantic violations (sentence comprehension). Of the four measurements, one will take place in a 7-Tesla (7T) scanner and the rest will occur at a 3-Tesla (3T) scanner. The repeated measurements at 3T will be used to assess reliability, whereas those from 7T will provide insight as to whether ultra-high-field MR is better suited for fMRI language mapping.

Expected Results

We predict that the object naming task, which involves overt language production, will be highly robust for localizing Broca’s area. Moreover, we expect that this task together with the sentence comprehension task will consistently and reliably map language areas in the dominant frontal, temporal, and parietal lobes. The results of this study will shed light on paradigm reliability and the impact of parameter choice for language mapping with fMRI.

References

[1] Agarwal, S., Sair, H. I., Gujar, S., and Pillai, J. J. “Language Mapping with fMRI: Current Standards and Reproducibility,” Topics in Magnetic Resonance Imaging vol. 28 no. 4 pp. 225–233 2019.

[2] Manan, A.M., Franz, E.A., and Yahya, N. “Utilization of functional MRI language paradigms for pre-operative mapping: a systematic review,” Neuroradiology vol. 62 pp. 353–367 2020.