Magnetic resonance imaging and spectroscopy in the study in ADHD syndrome: a short review

This short review describes findings on the characterization of attention-deficit/hyperactivity disorder (ADHD) performed with Magnetic Resonance (MR) techniques. Magnetic Resonance Imaging (MRI) is a powerful technique to discriminate different soft tissues in human body and allows morphological studies in symp- tomatic subjects. Functional Magnetic Resonance Imaging (fMRI) adopts MRI techniques to detect regional changes of cerebral metabolism in response to a specific activation. If brain activation is achieved by means of appropriate drugs fMRI is called pharmacological MRI (phMRI). The most popular fMRI technique utilizes the blood oxygenation level dependent (BOLD) contrast, which is based on the different magnetic properties of oxygenated and deoxygenated blood. fMRI and phMRI are important tools for understanding impairment in cognitive function and brain development in children with ADHD in humans as well as in animal model. We also review recent in vivo Magnetic Resonance Spectroscopy (MRS) studies of neurobehavioral syndromes. In vivo MRS include a number of non-invasive techniques able to detect biochemical information in a lo- calised brain region, in particular the alterations of metabolism in symptomatic subjects. All these techniques reveal morphological and functional differences between normal and ADHD subjects opening new views in comprehension of the mechanisms which are at the basis of this pathology.