Application of Advanced Neuroimaging Modalities in Pediatric Traumatic Brain Injury

Stephen Ashwal, Karen A. Tong, Nirmalya Ghosh, Brenda Bartnik-Olson, Barbara A. Holshouser
2014 Journal of Child Neurology  
Neuroimaging is commonly used for the assessment of children with traumatic brain injury and has greatly advanced how children are acutely evaluated. More recently, emphasis has focused on how advanced magnetic resonance imaging methods can detect subtler injuries that could relate to the structural underpinnings of the neuropsychological and behavioral alterations that frequently occur. We examine several methods used for the assessment of pediatric brain injury. Susceptibility-weighted
more » ... is a sensitive 3-dimensional high-resolution technique in detecting hemorrhagic lesions associated with diffuse axonal injury. Magnetic resonance spectroscopy acquires metabolite information, which serves as a proxy for neuronal (and glial, lipid, etc) structural integrity and provides sensitive assessment of neurochemical alterations. Diffusion-weighted imaging is useful for the early detection of ischemic and shearing injury. Diffusion tensor imaging allows better structural evaluation of white matter tracts. These methods are more sensitive than conventional imaging in demonstrating subtle injury that underlies a child's clinical symptoms. There also is an increasing desire to develop computational methods to fuse imaging data to provide a more integrated analysis of the extent to which components of the neurovascular unit are affected. The future of traumatic brain injury neuroimaging research is promising and will lead to novel approaches to predict and improve outcomes. Each of the authors contributed to the literature review and writing of the manuscript as follows: SA prepared the introductory material and the section on diffusion-weighted imaging; KAT wrote the section on susceptibility-weighted imaging; NG was responsible for the section on computational analysis; BBO prepared the section on diffusion tensor imaging; and BAH wrote the section on magnetic resonance spectroscopy. BAH, BBO, and KAT prepared all figures. All authors reviewed the entire manuscript prior to submission. Keywords children; diffusion tensor imaging; diffusion-weighted imaging; infants; magnetic resonance imaging; magnetic resonance spectroscopy; traumatic brain injury Advances in neuroimaging over the past 2 decades have greatly helped in the clinical care and management of children with traumatic brain injury. 1-6 Immediately after injury, computed tomography (CT) is important for rapid detection of extra-axial hemorrhage (eg, subdural or epidural hematomas), acute hydrocephalus, fractures, or other intracranial lesions that require acute neurosurgical intervention. 7 Magnetic resonance imaging (MRI) is very sensitive for intraparenchymal lesion detection but frequently is not acquired acutely. Newer and more sensitive imaging techniques are now used to better characterize the nature and evolution of injury and the underlying mechanisms that lead to progressive neurodegeneration, recovery or subsequent plasticity. These advanced methods also have begun to demonstrate that "normal appearing" brain as examined with CT or with conventional MRI may not adequately depict brain injury. 7 This review will describe 3 advanced MRI techniques that are of value in the acute and chronic periods after traumatic brain injury in children. They include (1) susceptibilityweighted imaging; (2) magnetic resonance spectroscopy, particularly magnetic resonance spectroscopic imaging; and (3) diffusion-weighted and diffusion tensor imaging. Several of these methods appear particularly useful for the assessment of diffuse axonal injury that is responsible for a wide range of motor and cognitive impairments. Studies exploring the human connectome, examining the brain's structural and functional interrelationships, are also being used to study brain development as well as genetic and acquired diseases, and in the future should provide important information regarding traumatic brain injury. 8-10
doi:10.1177/0883073814538504 pmid:24958007 pmcid:PMC4388155 fatcat:floien4nevgm3j6rdsqnyriov4