title: Structural imaging of mild traumatic brain injury may not be enough: overview of functional and metabolic imaging of mild traumatic brain injury.
abstract: A majority of patients with traumatic brain injury (TBI) present as mild injury with no findings on conventional clinical imaging methods. Due to this difficulty of imaging assessment on mild TBI patients, there has been much emphasis on the development of diffusion imaging modalities such as diffusion tensor imaging (DTI). However, basic science research in TBI shows that many of the functional and metabolic abnormalities in TBI may be present even in the absence of structural damage. Moreover, structural damage may be present at a microscopic and molecular level that is not detectable by structural imaging modality. The use of functional and metabolic imaging modalities can provide information on pathological changes in mild TBI patients that may not be detected by structural imaging. Although there are various differences in protocols of positron emission tomography (PET), single photon emission computed tomography (SPECT), functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and magnetoencephalography (MEG) methods, these may be important modalities to be used in conjunction with structural imaging in the future in order to detect and understand the pathophysiology of mild TBI. In this review, studies of mild TBI patients using these modalities that detect functional and metabolic state of the brain are discussed. Each modality's advantages and disadvantages are compared, and potential future applications of using combined modalities are explored.
authors.affiliation: Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Samuel S
authors.initials: SS
authors.lastname: Shin
authors.affiliation: Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, USA.
authors.forename: James W
authors.initials: JW
authors.lastname: Bales
authors.affiliation: Department of Neurosurgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Edward Dixon
authors.affiliation: Russel H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 1800 Orleans St Zayed Tower 4174, Baltimore, MD, 21287, USA. mhwang11@jhmi.edu.
authors.forename: Misun
authors.initials: M
authors.lastname: Hwang
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D001924:Brain Concussion / Q000378:metabolism* / Q000473:pathology*; D001931:Brain Mapping / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D019317:Evidence-Based Medicine; D006801:Humans; D057054:Molecular Imaging / Q000379:methods; D013329:Structure-Activity Relationship
chemical_list: D015415:Biomarkers
keywords: Concussion; Diffusion tensor imaging; DTI; Imaging; Mild traumatic brain injury; TBI