http://www.medscape.com/viewarticle/848066
“Persons with TBI or PTSD can present with overlapping symptoms, making them challenging to tell apart,” coauthor Cyrus Raji, MD, PhD, from the University of California, Los Angeles (UCLA), told Medscape Medical News. “SPECT imaging can be effectively used in both inpatient and outpatient settings to understand if a patient may have PTSD as opposed to TBI. In our study, SPECT shows that persons with TBI have abnormally decreased blood flow while those with PTSD have abnormally elevated perfusion in certain brain regions.”