Neuroimaging is the way in which medical science looks at the brain. Anatomical imaging, such as X-Ray computed tomography (CT) scans and anatomical magnetic resonance imaging (MRI), are often the first modality used to assess a case of traumatic brain injury (TBI). Functional brain imaging, such as perfusion SPECT, Positron Emission Tomography (PET), and functional Magnetic Resonance Imaging (fMRI), allow you to examine brain function. Perfusion SPECT is ideally suited to characterize the extent of neurological impairment in a case of TBI and to demonstrate changes in brain function following near-infrared light therapy (NILT). Perfusion SPECT utilizes a radioactive tracer to demonstrate cerebral regional blood flow. Blood flow and brain activity are tightly linked. As an area of the brain becomes more active, blood flow to that area increases in a proportional manner. This is the basis for both functional MRI (fMRI) and SPECT functional brain imaging. SPECT is superior at demonstrating TBI compared to CT and MRI scans.
Overall, anatomic CT or MRI scans detect less than one-half of the numbers of lesions found in SPECT scans of symptomatic TBI patients. When processed with statistical parametric analysis, SPECT provides a powerful tool to aid in the diagnosis of TBI.
For example, in the studies below, we were able to distinguish between TBI and Post-Traumatic Stress Disorder (PSTD). Both TBI and PTSD have symptoms that can mimic each other, which can mislead some diagnosis and resulting treatments.
- Traumatic Brain Injury (TBI) Can Now Be Identified, Say Researchers in Largest Neuroimaging Study
- Uncovering PTSD and TBI Treatments Despite Similarities
In addition, SPECT appears to have utility in effectively tracking treatment results and functional outcome. For example, a baseline SPECT has 100% negative predictive value and 100% sensitivity and 85% specificity compared to neuropsychological testing at baseline, 6 months, and 12 months follow-up. These data were recently extensively reviewed in a quantitative analysis by a team of physicians lead by Dr. Henderson. To summarize, a total of 903 patients included in 19 longitudinal studies and 2,121 patients in 52 cross-sectional studies of TBI were reviewed. The areas most commonly injured in TBI are the frontal lobe (94%) and the temporal lobe (77%) of studies.
