Updated on 2 December 2013
"MRI relaxation rates are the more conventional way to measure brain iron, but they are not very specific," Dr Adisetiyo said. "We added MFC because it offers more refined specificity."
The results showed that the 12 ADHD patients, who had never been on medication, had significantly lower MFC than the 10 ADHD patients who had been on psychostimulant medication or the 27 typically developing children and adolescents in the control group. In contrast, no significant group differences were detected using relaxation rates or serum measures. The lower brain iron levels in the non-medicated group appeared to normalize with psychostimulant medication.
MFC imaging's ability to noninvasively detect the low iron levels may help improve ADHD diagnosis and guide optimal treatment. Noninvasive methods are particularly important in a pediatric population, Dr Adisetiyo noted.
"This method enables us to exploit inherent biomarkers in the body and indirectly measure dopamine levels without needing any contrast agent," she said.
If the results can be replicated in larger studies, then MFC might have a future role in determining which patients would benefit from psychostimulants-an important consideration because the drugs can become addictive in some patients and lead to abuse of other psychostimulant drugs like cocaine.