Pictured left: MRI image showing the fusion of a vein scan and a lesion scan. the dark lines are the veins and the bright spots are the lesions. Right: Isolated vein scan.
In order to effectively use brain imaging to diagnose diseases, physicians and other healthcare professionals need to know what they are looking at. New guidelines co-authored by MRI scientist and physicist Dr. Alex Rauscher, published recently in Nature Reviews Neurology, may improve the process of diagnosis for multiple sclerosis (MS).
MS is a disease of the central nervous system, and though symptoms are variable the disease is a frequent cause of disability. In MS, inflammation causes loss of myelin (a fatty tissue that protects nerve fibres), resulting in damage to brain tissue. On conventional MRI, MS lesions present as bright areas, which can be difficult to distinguish from lesions caused by other conditions, such as migraine or cerebral small vessel disease. However, MS lesions predominantly form around small veins in the brain. Combining maps of MS lesions with maps of veins would create images that allow radiologists to better distinguish MS from its mimics.
Dr. Rauscher is a member of the North American Imaging in Multiple Sclerosis Cooperative, who recently came together to issue a set of recommendations aimed at helping radiologists and neurologists to better understand, refine, standardize and evaluate vein imaging in the diagnosis of MS.
“Veins carry blood with low oxygen content, which makes them more magnetic than the surrounding tissue,” says Dr. Rauscher. “The magnetism created by veins acts as a magnifying glass, which allows us to visualize veins almost as thin as a human hair. We are now able to map the brain’s entire venous architecture within a few minutes.”
“Once we know which lesions contain veins and which do not, we believe we can diagnose MS earlier, enabling physicians to begin treatment in the beginning stages of the disease course,” says Dr. Rauscher. “Vein mapping will eventually become part of the standard MRI protocol to aid the diagnosis of MS. But what we need more urgently are MRI scans that are able to tell us whether a new treatment or drug is working.”
“The ability to track tissue repair using MRI is crucial for the evaluation of future drugs. My lab’s main goal is to develop MRI scans that are able to do exactly that,” says Dr. Rauscher. “We believe that the advanced MRI scans currently under development are going to have a big impact on how MS is diagnosed and treated.”