Emerging imaging tools for use with traumatic brain injury research

Abstract

This article identifies emerging neuroimaging measures considered by the inter-agency Pediatric Traumatic Brain Injury (TBI) Neuroimaging Workgroup. This article attempts to address some of the potential uses of more advanced forms of imaging in TBI as well as highlight some of the current considerations and unresolved challenges of using them. We summarize emerging elements likely to gain more widespread use in the coming years, because of 1) their utility in diagnosis, prognosis, and understanding the natural course of degeneration or recovery following TBI, and potential for evaluating treatment strategies; 2) the ability of many centers to acquire these data with scanners and equipment that are readily available in existing clinical and research settings; and 3) advances in software that provide more automated, readily available, and cost-effective analysis methods for large scale data image analysis. These include multi-slice CT, volumetric MRI analysis, susceptibility-weighted imaging (SWI), diffusion tensor imaging (DTI), magnetization transfer imaging (MTI), arterial spin tag labeling (ASL), functional MRI (fMRI), including resting state and connectivity MRI, MR spectroscopy (MRS), and hyperpolarization scanning. However, we also include brief introductions to other specialized forms of advanced imaging that currently do require specialized equipment, for example, single photon emission computed tomography (SPECT), positron emission tomography (PET), encephalography (EEG), and magnetoencephalography (MEG)/magnetic source imaging (MSI). Finally, we identify some of the challenges that users of the emerging imaging CDEs may wish to consider, including quality control, performing multi-site and longitudinal imaging studies, and MR scanning in infants and children.

FIG. 1.

CT (A) only shows a few small hyperdense hemorrhages in the corpus callosum (dashed white arrow) of a child with TBI. T2WI (B) is not sensitive to hemorrhage, although ill-defined T2 hyperintense areas of edema are detected in the corpus callosum and the periphery of the hemispheres (double line black arrows). Conventional T2*-WI (C) is routinely used to detect hemorrhage, which demonstrates small hypointense hemorrhagic contusions along the brain surface as well as hemorrhagic shearing injury in the corpus callosum (solid black arrows). However, susceptibility-weighted imaging (SWI) (D) is significantly more sensitive to hemorrhage, and shows many more hemorrhages (white arrows) than any of the other images.