&Bullet; physics 14, 44
An undergraduate student is developing an imaging analysis technique to rapidly diagnose autism spectrum disorders that could allow clinicians to start treatment earlier than is currently possible.
Physics is the science of the universal: finding common rules that determine the behavior of different systems. Medical physicists take a different approach, however, as many diseases require tailored rather than blanket treatment plans. This is where a new technique for characterizing structures in the brain could prove useful, hopes Shannon Brindle, a physics major last year working in Rasha Makkia’s laboratory at the University of Mary Washington, Virginia. For example, she envisions that advanced brain imaging analysis techniques could help clinicians determine, at a younger age than is currently possible, whether a child has an autism spectrum disorder, determine its severity, and then intervene better match the child’s individual needs. Brindle discussed their results in a talk at this year’s March meeting of the American Physical Society.
One in five children in the US is diagnosed with autism every year, five times the number of children with cancer. However, there won’t be any blood or imaging tests for the disorder. Rather, the disorder that develops in early childhood is diagnosed by examining a child’s ability to communicate and interact with other people. That means it can take some time for a family to receive a formal diagnosis, which can delay treatment and upset parents for responses.
Brindle, who has three cousins with autism, understands these difficulties all too well. When it came time to choose her undergraduate research project, she was immediately drawn to one who had the potential to help fix the problem. “This problem is very close to my heart,” she says. “This project was very family-oriented.”
Brindle, along with another student, Clark Saban, helped develop a computer technique that would allow multiple structures to be extracted simultaneously from 3D magnetic resonance imaging brain scans, which other methods cannot. The technique isolates the structures and then renders them using graphical representations called NURBS, which more accurately capture and maintain the topological intricacies of the structures than other methods. Brindle used her technique to characterize two structures: the cerebellum, which is located in the back of the brain and is involved in controlling motor functions, and the corpus callosum, a C-shaped bundle of nerve fibers, the right and the left brain connects sides. Changes in the size of neurons within these structures and the function of these brain regions have been linked to autism. The structures are also easy to identify, making them promising targets for diagnosing the disease, says Brindle.
To test her method, Brindle applied it to images of the brains of two 8-year-old boys diagnosed with autism and an 8-year-old boy who was not. Brindle notes that boys are more likely to have autism than girls, a factor that played a role in image selection. As a student, she has limited access to scans. “These were the ones that were available to me now,” she says.
Brindle analyzed the structures and made two observations. First, she found that in boys with autism, the cerebella was larger while the corpus callosa was smaller, which was expected from other autism studies. Second, the right “stalk,” known as the stalk, that connects the cerebellum to the rest of the brain, was smaller than the left stalk in boys with autism. The opposite was the case for the other boy. While the measurements seem meaningful, Makkia notes that they do not yet need to undergo a thorough review, either in her laboratory or through peer review. She also notes that in published results for girls with autism, the left stem is the larger. However, a radiologist has confirmed that Brindle’s technique correctly isolated the structures, Makkia says.
With preliminary results in only three patients, it is obviously too early to suggest that the observations have clinical significance. But perhaps a student’s ingenuity could offer a fresh approach to a longstanding problem. Brindle hopes to enroll more patients in the study when it starts graduate school. She also intends to expand her method to monitor other diseases in children, such as: B. cancerous brain tumors. The hope is to provide tools that doctors can use to develop more personalized treatment plans for a wide variety of conditions. “If I were a parent, I’d love to see doctors use a computer model to do calculations specifically for my child to make sure they’re safe,” she says.
– Katherine Wright
Katherine Wright is the assistant editor of physics.