PET/MRI imaging as a practical tool in evaluating mild traumatic brain injury (mTBI)

Objectives: raumatic brain injury (TBI) due to contact sports is the cause of more than 200,000 emergency room visits and 1.7 million reported new cases each year in the United States, which contributes to one third of all deaths due to injury. Almost 75% of all reported TBIs are mild traumatic brain injury (mTBI) or concussion, although the number of unreported mTBIs remains unknown. Sports-related repetitive mild TBI may lead to chronic variations in mood, behavioral, and cognition. Studies of retired athletes in contact-sports, such as National Football League (NFL) players, show a higher rate of personality, behavioral, and mood disorders (depression, irritability, impulsiveness), mild cognitive impairment (MCI, a predisposing factor for dementia), and dementia. Currently, mTBI or concussion is identified by means of clinical assessment using symptom monitoring, physical examination, and neurocognitive testing which is inadequate in its ability to evaluate the extent of injury and recovery. Traditional structural imaging like standard magnetic resonance imaging (MRI) or computed tomography (CT) are sometimes characteristically inconclusive due to subtle, obscure, or absent changes in anatomical or physiological parameters. Quantitative molecular imaging techniques that assess functional processes in the brain, such as positron emission tomography (PET), have the ability to detect even minute changes due to mTBI. Recent technological improvements in the integration of PET with MRI, and more sophisticated image analysis and quantification methods would contribute to the growing usage of combined PET/MRI modalities in preclinical research and advances in clinical imaging of mTBI. This exhibit will review: 1) The current state of PET/MRI imaging in assessing mTBI in clinical and preclinical research. 2) Technological considerations, potential applications and limitations of combined PET/MRI imaging in mTBI, compared with other available modalities 3) Advances in neuroimaging techniques and quantification methods that have the potential to provide more objective data