Functional MR Imaging: Blood Oxygen Level-Dependent and Resting State Techniques in Mild Traumatic Brain Injury

This article discusses mild traumatic brain injury (mTBI)-associated effects on brain functional connectivity assessed via resting-state functional MR imaging. Several studies have reported acute postinjury default mode network hyperconnectivity, followed by a period of decreased connectivity before later connectivity normalization in some patients. Other studies have reported mTBI-associated effects on connectivity that remain evident for up to 5 years or more. Discordance in the published literature regarding the direction of network connectivity changes (eg, increased versus decreased connectivity) may reflect differences in timing of data collection post injury, as well as the need to standardize MR imaging acquisition protocols and processing methods.