Advanced Neuroimaging Role in Traumatic Brain Injury: A Narrative Review

Abstract

Traumatic brain injury (TBI) is a common source of morbidity and mortality among civilians and military personnel. Initial routine neuroimaging plays an essential role in rapidly assessing intracranial injury that may require intervention. However, in the context of TBI, limitations of routine neuroimaging include poor visualization of more subtle changes of brain parenchymal after injury, poor prognostic ability and inability to analyze cerebral perfusion, metabolite and mechanical properties. With the development of modern neuroimaging techniques, advanced neuroimaging techniques have greatly boosted the studies in the diagnosis, prognostication, and eventually impacting treatment of TBI. Advances in neuroimaging techniques have shown potential, including (1) Ultrasound (US) based techniques (contrast-enhanced US, intravascular US, and US elastography), (2) Magnetic resonance imaging (MRI) based techniques (diffusion tensor imaging, magnetic resonance spectroscopy, perfusion weighted imaging, magnetic resonance elastography and functional MRI), and (3) molecular imaging based techniques (positron emission tomography and single photon emission computed tomography). Therefore, in this review, we aim to summarize the role of these advanced neuroimaging techniques in the evaluation and management of TBI. This review is the first to combine the role of the US, MRI and molecular imaging based techniques in TBI. Advanced neuroimaging techniques have great potential; still, there is much to improve. With more clinical validation and larger studies, these techniques will be likely applied for routine clinical use from the initial research.

Magnetic Resonance Spectroscopy of Traumatic Brain Injury and Subconcussive Hits: A Systematic Review and Meta–Analysis

“…Research to best understand the full continuum of brain injury is expanding with increasing use of magnetic resonance imaging to understand brain injury as well as to predict outcomes and inform treatments. 13–15 Included in this approach is magnetic resonance spectroscopy (MRS), which provides neurochemical information about brain tissue. Briefly, MRS uses a typical magnetic resonance imaging scanner to quantify concentrations of specific metabolites.…”

Use of MRI in patients with severe diffuse traumatic brain injury: A matched National Trauma Data Bank analysis

“…For long-term prognostication of TBI, MRI has been shown to be a valuable and accurate tool, especially with regard to visualization and grading of injury. 9,19,20 While MR imaging and related modalities (diffusion tensor imaging, spectroscopy, etc.) are valuable in these contexts, this study evaluated its usefulness in the acute setting.…”

“…Endpoints of existing studies have largely focused on longer-term outcomes (such as 1 month or 1 year), largely using Glasgow Outcome Scale-related metrics, whereas our analysis evaluated more acute outcome variables related to in-hospital and disposition endpoints. For long-term prognostication of TBI, MRI has been shown to be a valuable and accurate tool, especially with regard to visualization and grading of injury 9,19,20 . While MR imaging and related modalities (diffusion tensor imaging, spectroscopy, etc.)…”

“…7 Because MRI is more sensitive in detecting smaller intracranial hemorrhages, shear injuries, white matter lesions, and diffuse axonal injury (DAI), as well as allowing estimation of the age of intraparenchymal contusions, many medical centers have increasingly utilized MRI and MR-based sequences (such as diffusion tensor imaging) to aid in prognostication of patients admitted with severe TBI. [8][9][10][11] However, the clinical value of MRI in this context is a matter of debate, and practices for obtaining such imaging vary among institutions and patient populations and even among providers at the same institution. Most research has been focused on the pediatric population, where lack of radiation makes MRI more attractive.…”

Cerebral metabolic derangements following traumatic brain injury

“…Noninvasive proton ( 1 H-MRS) and phosphorus ( 31 P-MRS) magnetic resonance spectroscopy can also be used to study cerebral metabolism. Such advanced imaging techniques can provide detailed understanding of the burden and spatial heterogeneity of metabolic derangements seen following TBI [ 4 ▪▪ , 5 ▪▪ , 19 ].…”