Neuroimage. Available online 12 September 2017
The human brain contains two types of tissues, which are known as white and grey matter. Grey matter is where information is processed in the brain. White matter connects areas of grey matter through nerve fibers called axons, which are coated in myelin. Myelin insulates the axons and increases the speed at which impulses travel through the brain. The amount of myelin in certain areas of the brain has been associated with cognitive and motor abilities, as well as behaviour. Also, a loss of myelin is observed in certain disorders and diseases, and is associated with functional impairment.
Magnetic resonance imaging (MRI) allows clinicians and researchers to assess the structure of living brains, including myelin. Utilizing MRI to study brain white matter in healthy and disease states is vital to understand normal brain health and to determine if changes in myelin contribute to certain diseases. Assessing myelin non-invasively also enables clinicians to monitor a patient’s progression and response to certain treatments.
The goal of this study was to compare three MRI techniques and determine which provides the most accurate and specific information on myelin in the brain. The MRI scans of 23 healthy children aged 8-13 were used to compare and contrast the various measures of myelin obtained from each technique. The results of the study demonstrated that all three techniques allowed for the detection and quantification of myelin levels in the brain. However, the most specific measures of myelin were obtained from the two recently developed, less commonly used MRI methods. This study has shown that new myelin imaging techniques provide advantages over the current gold standard. The insights from this study will allow clinicians and researchers to better understand myelin imaging techniques, and choose the correct technique given the benefits and limitations of each.