Novel MRI Finds Clues to Developmental Delays
Technology may offer new ways to diagnose childhood disorders, assess treatments
TUESDAY, Sept. 30, 2003 (HealthDayNews) -- A new magnetic resonance imaging (MRI) technique may be able to pick up abnormalities in the brains of children with developmental delays that no other imaging technique has been able to find before.
In the October issue of Radiology, researchers explain how diffusion-tensor MRI shows differences in the brains of developmentally delayed children compared to children who are developing normally.
"Diffusion-tensor MRI gives you microscopic detail of the brain," says study author Dr. Christopher Fillipi, who was an assistant professor of neuroradiology at New York Presbyterian Hospital-Weill Medical College of Cornell University in New York City at the time of the study.
"Fiber tracts connect one part of the brain to another. So, we looked to see if the fiber tract quantitative values were normal [in children with development delays]," Fillipi adds. "The values in these children were abnormal and not just in the area expected, but throughout the brain."
Fillipi and his colleagues recruited 20 children between the ages of 2 and 8 who had been diagnosed with either an isolated language or motor skill developmental delay. Standard MRI findings for these children were normal.
The researchers also recruited 10 children without developmental delays to serve as controls. In each group, half were male and half were female.
All 30 youngsters underwent diffusion-tensor MRI scanning, which, from a patient's perspective, is done just as standard MRI is done. Fillipi explains that a different radiofrequency pulse is used during this test and it measures how water travels through cell membranes.
When humans are born, there is a lot of water in the brain, he explains. As the brain develops, fiber tracts form, connecting sections of the brain. When that happens, the amount of water decreases. With diffusion-tensor MRI, radiologists can see where microscopic fiber tracts have formed in the brain by the way water travels around them.
What they found, he says, is that "some kids are wired differently." Children with developmental delays didn't have as many fiber tracts as normally developing children. Also, the differences weren't just in the areas that you'd expect, such as the language center of the brain in a child having difficulty with speech, but across the brain. Yet, in a standard MRI, no abnormalities had shown up.
Fillipi says that this type of imaging could help reassure parents, because there is a biological basis for the problem. He adds this technique could also be used to measure the effectiveness of physical and occupational therapy to see if these interventions increase the development of fiber tracts.
Dr. Richard Silbergleit, director of neuro-imaging at William Beaumont Hospital in Royal Oak, Mich., says this type of imaging is where radiology is heading in the future. "They're not just imaging how the brain looks, but they're looking more at how it functions," he explains.
Silbergleit does point out, however, that because this technology is so new, researchers don't know what "normal" values are. In this study, for example, he says that the age range was from 2 to 8, but the researchers don't know yet what normal is for each age because all ages were lumped together.
Additionally, he says parents need to know that this technology is not yet widely available.
Fillipi says this type of MRI "holds great promise." In the future, it may also be used to find improper connections in other neuropsychiatric disorders.