Noninvasive magnetic resonance imaging techniques in mild traumatic brain injury research and diagnosis

Abstract

Mild traumatic brain injury (mTBI), frequently referred to as concussion, is one of the most common neurological disorders. The underlying neural mechanisms of functional disturbances in the brains of concussed individuals remain elusive. Novel forms of brain imaging have been developed to assess patients postconcussion, including functional magnetic resonance imaging (fMRI), susceptibility‐weighted imaging (SWI), diffusion MRI (dMRI), and perfusion MRI [arterial spin labeling (ASL)], but results have been mixed with a more common utilization in the research environment and a slower integration into the clinical setting. In this review, the benefits and drawbacks of the methods are described: fMRI is an effective method in the diagnosis of concussion but it is expensive and time‐consuming making it difficult for regular use in everyday practice; SWI allows detection of microhemorrhages in acute and chronic phases of concussion; dMRI is primarily used for the detection of white matter abnormalities, especially axonal injury, specific for mTBI; and ASL is an alternative to the BOLD method with its ability to track cerebral blood flow alterations. Thus, the absence of a universal diagnostic neuroimaging method suggests a need for the adoption of a multimodal approach to the neuroimaging of mTBI. Taken together, these methods, with their underlying functional and structural features, can contribute from different angles to a deeper understanding of mTBI mechanisms such that a comprehensive diagnosis of mTBI becomes feasible for the clinician.

Building bridges: simultaneous multimodal neuroimaging approaches for exploring the organization of brain networks

“…The potential impact of a better understanding of the BOLD signal is far-reaching given that this measure offers noninvasive whole-organ coverage and is widely used across species, thus providing a link between basic research and patient management. Further, there is significant evidence, although much of it is correlative, that brain network measures derived from BOLD contrast (i.e., functional connectivity) may have utility as a diagnostic and prognostic tool for a variety of neurological conditions as well as brain injuries and diseases (see select reviews by Wang et al, 57 Lunkova et al, 58 Harikumar et al, 59 Yoon et al, 60 and Kanel et al 61 ). The combination of fMRI with complementary modes not only helps discern what measures may be most useful clinically but also stands to yield mechanistic insight into the biology that underpins BOLD signal differences between individuals, populations, and time points.…”

Neuropathological Mechanisms of Mild Traumatic Brain Injury: A Perspective From Multimodal Magnetic Resonance Imaging

“…With the development of magnetic resonance imaging (MRI) techniques, several novel multimodal imaging approaches can clearly show the potential neuropathological changes of mTBI, such as functional MRI (fMRI), arterial spin labeling (ASL) perfusion imaging, susceptibility-weighted imaging (SWI), and diffusion MRI (dMRI). These imaging techniques can be used to locate the injured brain functional area more accurately, so as to comprehensively evaluate the severity of the craniocerebral injury, greatly improve the early diagnosis accuracy of mTBI, and play a pivotal role in prognosis evaluation (Lunkova and Guberman, 2021). Nevertheless, these results have been blended with a more common application and a slower integration into the clinical setting.…”

Use of Novel Concussion Protocol With Infralow Frequency Neuromodulation Demonstrates Significant Treatment Response in Patients With Persistent Postconcussion Symptoms, a Retrospective Study

“…Using a magnetic resonance imaging (MRI) technique termed symmetric normalization for multivariate neuroanatomy (SyNMN) investigators provided evidence that TBI lesions significantly compromise paralimbic structures (dorsomedial thalamus and hippocampus) ( Avants et al, 2008 ). Multimodal studies using magnetic resonance imaging have recently improved the more widespread and specific detection of DAI injuries with notable consistent mention of these same paralimbic structures ( Lunkova et al, 2021 ). Posttraumatic (non-concussive) stress disorder (PTSD) is a psychiatric condition sharing similar symptoms of postconcussion syndrome and when both disorders co-exist in post-combat veterans the condition is conceptualized as “consequence of war syndrome” (CWS) ( Dieter and Engel, 2019 ).…”