After a mortar exploded next to Spc. James Saylor last year in Afghanistan, he underwent a series of scans to see how the explosion affected his brain. Standard CT scans showed no obvious signs of damage, but his symptoms were impossible to ignore.
The 31-year-old father of two was quick to anger and had vivid nightmares and short-term memory loss. So his doctors at the Army's Fort Campbell tried a brain imaging procedure more commonly used to study dementia and found decreased levels of blood flow in some areas of his brain.
"What's interesting here is that we are seeing things here that we can't see in their standard CT scan," said Maj. Andrew Fong, chief of radiology at the post's Blanchfield Army Community Hospital. "We also can't see it on a traditional MRI."
The scan, called single-photon emission computerized tomography or SPECT, produces data about the level of perfusion, or blood flow inside the brain, which is rendered in colors from red and white to blue and grey. The results helped doctors confirm their diagnosis of a brain injury and determine treatment.
Since 2000, the military estimates more than 200,000 soldiers have mild traumatic brain injuries, or concussions, which has become the signature wound from extended guerrilla wars. But the military is finding these wounds created by improvised explosive devices can be as hard to catch as they are to treat.
While normal CT scans can find contusions and brain bruising, more sophisticated technology is needed to help radiologists and neurologists determine more subtle changes to the brain, Fong said.
Fong said while the SPECT scan has been used to study dementia and Alzheimer's, it's underused in the military. Fort Campbell is one of only two military installations to use the scan to study traumatic head injuries and concussions caused by war, he said.
"We're basically looking at soldier's brain function and we are noticing a decline in brain function in certain areas of the brain," Fong said. "Standard equipment and standard software shows no abnormality most of the time."
In the scans, colors correspond to the level of blood flow, with white and red showing areas of high perfusion and darker areas showing low perfusion. Some more active areas of the brain naturally are "hotter" than other parts and age can also slow down blood flow, Fong said.
"When you are younger, like a lot of our soldiers are, you expect a lot of perfusion _ a lot of activity because their brains are fresh," he said.
But as Fong started looking at soldiers who were coming back from war with brain injuries, he saw large areas of their brains that were less active than normal. "We are seeing in these guys with decreased perfusion and they are in their 20s," Fong said.
Pointing to a dark area in one image, he notes they've been seeing several soldiers who have less blood flow in the temporal lobes. Once he started discussing the scans with Dr. David Twillie, director of Fort Campbell's brain injury center, they wondered whether the scans were showing them the effects of a blast injury. The temporal lobes sit behind the eye sockets on either side of the brain and are in the path of the shockwaves produced by blasts, Fong explains. "We are thinking maybe that is related," Fong said.
In addition to his brain injury, Saylor was also diagnosed with post-traumatic stress disorder. He's been taking medications for his nightmares, which were at times vivid enough that his wife, Tiffany, had to wake him up because he was fighting in his sleep.
"You relieve what you've been through, over and over," he said. "You see other things that could have happened. It's a constant battle."
Twillie said that the scans can also illustrate areas of the brain that are overactive, which can be associated with symptoms of PTSD.
"Some patients have both TBI and PTSD, which in our population, about half have a dual diagnosis," he said. "Dr. Fong will alert us to areas of increased blood flow in the places where emotions are controlled. It will help us confirm the diagnosis that we are seeing clinically."
In the beginning, Saylor, like a lot of soldiers, wasn't entirely convinced that a concussion could be causing his symptoms.
"When I first came in, I was like, `Why am I going through this program?'" he said. "I've had a concussion before when I was younger, playing football."
But as his doctors started to show him how the injury affected his mood and function, he said he now has a better understanding of how to control his emotions. His wife, who has been supporting him through the rehabilitation, said the scans were an eye-opener.
"You can see what is wrong," Tiffany said. "It's set down in front of you in black, blue, orange and yellow."
Fort Campbell has had the technology for the SPECT scan less than a year and Twillie is hoping to continue using the scans to see whether the treatment for soldiers like Saylor is improving the blood flow in their brains.
Saylor has learned to monitor and regulate his irritability through an application on his smartphone. When he starts to get upset and lose focus, he pulls out his phone and starts tapping the screen in time with his breathing. "It's just deep breathing," he explains. "I use that breathing technique to concentrate and clear my mind."
The visual images of his brain have helped Saylor's wife understand how this unseen injury has had such a large effect on his personality.
"You don't realize how something so small, like a bruised brain or a little bit of over activity or a little bit of under activity, how much that changes everything," Tiffany said. "To have this kind of machinery and technology to be able to see, it is phenomenal. That's the biggest thing."