Advanced MRI in Acute Military TBI

PUBLIC ABSTRACT

Traumatic brain injury can cause permanent problems with thinking, memory, control of emotions, organization, and planning. Thousands of soldiers, marines, and other military personnel have had injuries to the brain due to the wars in Iraq and Afghanistan. Very large numbers of civilians, up to perhaps 1.5 million people per year, in the United States also have traumatic brain injuries caused by car accidents, falls, sports-related injuries, or assault. We don't know very much about traumatic brain injuries right now, but there are some important new advances in technology that may help us learn a lot more about these injuries.

One such advance involves new types of MRI scans that we think will be able to show what has happened to the brain after trauma more clearly than regular scans can. The first new scan is called diffusion tensor imaging, which shows injury to the axons (the wiring of the brain). The second new scan is called resting-state functional MRI correlation analysis, which shows how well various parts of the brain are connected to each other. Importantly, the new types of scans can be done using regular scanners that we already have in every major hospital. The innovation is entirely in how the scanners are used and how the resulting pictures are analyzed on a computer after they have been taken. We have already tested these scans on some military and civilian patients with brain injury and found them to be very helpful so far.

What are the goals of the proposed study? Our overall goal is to see whether these new MRI scans will be useful for active duty military personnel who have had recent traumatic brain injuries. The most important goal will be to see if the amount of injury shown on the scans be used to predict how well the patients will do overall over the next 6-12 months. A related goal will be to see whether injuries to specific parts of the brain seen by these new scans can be used to predict whether patients will be likely to have specific problems like memory loss, attention deficit, depression, or post-traumatic stress disorder. We would also like to see whether the scans could be even more useful when combined with information about genetic factors (inherited from the parents) that can be tested in the blood. Another important goal is to compare the effects of traumatic brain injuries caused by blasts or explosions with injuries from other causes, to find out what is unique about blast injury. A final goal will be to repeat the scans 6-12 months later to see whether the new MRI scans can show whether the injuries to the brain have healed, gotten worse, or stayed the same.

What types of patients will it help? This study will help traumatic brain injury patients. It will be most useful for military personnel who have had recent brain injuries during active duty. It is likely to also be useful for young adult civilians who have had brain injuries due to car accidents, sports-related concussions, falls, assault, or other causes. It is possible, but not known for sure, whether it will help children or older adults with traumatic brain injuries. It is also possible that it may help people with other brain injuries or diseases. How will it help them? These new scans could help with decisions about whether military personnel can return to duty, what sort of rehabilitation and treatment would benefit them most, and what family members should watch for and expect.

What are the potential clinical applications, benefits, and risks? There are many potential direct clinical applications. These scans could improve the accuracy of diagnosing brain injuries, reveal brain injuries in people who initially do not report any symptoms but develop them later, and improve planning for rehabilitation. In some situations, they could help resolve issues relating to whether an individual person's symptoms are most likely to be caused by traumatic brain injury, post-traumatic stress disorder, or both. Overall MRI scanning is very safe and has no known major risks. Because the scanner uses strong magnets, anyone with metal objects in their bodies cannot be scanned, as this could be dangerous. There can be some psychological risks involved in taking tests and answering questions, but these are usually mild and can be managed. There is always a risk that important confidential information will be made public and that this could have consequences. We have carefully designed a plan to reduce all of these risks as much as possible.

What is the projected time it may take to achieve a patient-related outcome? These methods could become used in some hospitals within 2 years and could become standard in every major hospital within 5 years. What are the likely contributions of this study? If the study is successful, it will show that these new MRI techniques can be used to make more accurate diagnoses of traumatic brain injury, more accurate predictions of the sorts of problems that are likely to occur after brain injury, and more accurate assessments of how severe the injuries are. Scientifically, we will also learn more about how particular parts of the brain work together to perform specific functions, and how specific genetic factors affect these functions.