Structural Image Analysis of the Brain in Neuropsychology Using Magnetic Resonance Imaging (MRI) Techniques

Abstract

Magnetic resonance imaging (MRI) of the brain provides exceptional image quality for visualization and neuroanatomical classification of brain structure. A variety of image analysis techniques provide both qualitative as well as quantitative methods to relate brain structure with neuropsychological outcome and are reviewed herein. Of particular importance are more automated methods that permit analysis of a broad spectrum of anatomical measures including volume, thickness and shape. The challenge for neuropsychology is which metric to use, for which disorder and the timing of when image analysis methods are applied to assess brain structure and pathology. A basic overview is provided as to the anatomical and pathoanatomical relations of different MRI sequences in assessing normal and abnormal findings. Some interpretive guidelines are offered including factors related to similarity and symmetry of typical brain development along with size-normalcy features of brain anatomy related to function. The review concludes with a detailed example of various quantitative techniques applied to analyzing brain structure for neuropsychological outcome studies in traumatic brain injury.

Volumetric and shape analyses of subcortical structures in United States service members with mild traumatic brain injury

“…Across the range of TBI severity, these studies have demonstrated a number of consistent findings including global atrophy (i.e., ventricle-to-brain ratio; [5, 65]), white and gray matter atrophy [6, 47, 64], regional vulnerability (temporal and frontal poles [4]) specific subcortical nuclei atrophy (i.e., thalamus, [43]), and cortical thinning [38, 66, 73]). Recent advances in automated volumetric analysis (i.e., FreeSurfer) not only dramatically hasten the work, but typically improve reliability and consistency in measurements, making it possible to examine multiple regions of interest (ROI) concurrently.…”

“…One of the primary clinical and research tools employed in examining the effects of TBI on brain structure has been medical imaging, especially quantitative or volumetric magnetic resonance imaging (MRI; [5, 6, 17, 61, 72]). Across the range of TBI severity, these studies have demonstrated a number of consistent findings including global atrophy (i.e., ventricle-to-brain ratio; [5, 65]), white and gray matter atrophy [6, 47, 64], regional vulnerability (temporal and frontal poles [4]) specific subcortical nuclei atrophy (i.e., thalamus, [43]), and cortical thinning [38, 66, 73]).…”

Accelerated age‐related cortical thinning in mild traumatic brain injury

“…Brain volumetric changes are well‐characterized in those with a history of mTBI. Global and regional atrophy have been reported following mTBI (Bigler, ; Bigler & Maxwell, ; Mayer, Hanlon, & Ling, ), even many years postinjury. While gray and white matter volumetric changes are often reported with mTBI (Bigler, ; Tate, Khedraki, Neeley, Ryser, & Bigler, ), there have not been many studies examining changes specific to the cortical surface.…”

Creation of an anthropomorphic CT head phantom for verification of image segmentation

“…As outlined in the introduction, although the contrast available from MRI is considerably greater than CT, subtle differences in image acquisition and even scanning the same individual but on different scanners has the potential to yield different results. 56 Physical phantoms that can adequately simulate the human brain are not available, although digital brain phantoms have been used to demonstrate that SPM, FSL, and FreeSurfer underestimate GM and overestimate WM volumes with increasing noise. 24 Results from simulated images are always limited in their application because simulated images cannot capture the full complexity of real MR images and it has been demonstrated that, in the case of FSL FAST, it is not sufficient to use simulated images to get an idea of how a segmentation algorithm will perform on real datasets.…”