Advanced Imaging for Multiple Sclerosis
Multiple sclerosis (MS) presents with a variety of symptoms, and advanced imaging is one of the best ways doctors can verify a patient's diagnosis.
MS is a central nervous system disease in which the body attacks the protective covering, or myelin, of the brain, spinal cord or optic nerve. This creates injured white matter, called demyelinating lesions. We offer advanced imaging through our Yale Clinical Neurosciences Imaging Center, a place where cutting-edge research overlaps with excellent patient care. There, imaging specialists can work in conjunction with neurologists outside the department.
How is multiple sclerosis diagnosed?
When a primary care physician or a neurologist suspects that you have MS, they will follow a number of steps in order to confirm the diagnosis. That includes performing lab tests that include cerebrospinal fluid samples and blood tests.
You will also have your brain scanned. “Imaging answers two questions,” says Frank Minja, MD, a Yale Medicine radiologist and assistant professor of radiology and biomedical imaging at Yale School of Medicine. “They are: Are there areas of white matter injury? Is the white matter injury active or old?”
What makes a patient a good candidate for MS imaging?
Our patients typically fall into two categories: those who worry that they may have MS, based on preliminary diagnosis by their physician, and those who already have MS and seek updates on their disease.
For patients who already have the diagnosis, a magnetic resonance imaging scan (MRI) can help doctors study whether a therapy is working. For that purpose, they’ll check an image to see whether there are new lesions, or whether previous lesions continue to be active.
If a patient presents with new symptoms, Dr. Minja says, then images help doctors answer the question, “Are there lesions that might explain the symptoms a patient is having?”
What is unique about imaging for MS?
While general brain scans are often performed using computerized tomography (CT), MRIs are used to scan for MS; in the images, doctors are looking for abnormal white matter. “The benefit of MRI is that it shows a very good depiction of brain tissue compared to CT,” Dr. Minja says. MRIs do not deliver any radiation, which means that doctors and patients don’t have to worry about the risk factor of cumulative doses of radiation.
They often introduce gadolinium, an injected contrast dye, which helps to detect active white matter injury. Magnets in the MRIs used for MS screening have the strength of 3 Tesla—some of the strongest used clinically.
(Other imaging is typically done at half that strength, or 1.5 Tesla.) This strength allows for very high-resolution imaging; the stronger the magnet, the more detailed the image that’s created.
Some doctors are now using a 7 Tesla magnet for research purposes, to help them explore hypotheses about MS. While that probably won’t make an appearance in routine clinical use any time soon, the current machines provide plenty of detail for doctors who need to diagnose, monitor and treat.
What do doctors see in the images?
When reviewing an MRI scan, doctors can discern what brain matter is normal and what is abnormal, a distinction needed for diagnosis and for monitoring. The abnormal white matter is brighter than normal white matter, Dr. Minja says.
“It’s very striking,” he says. “You have a normal brain that’s grayish, and then a brain with MS has all these white dots superimposed on the background of gray.”
What happens after imaging?
Once a radiologist finds that a patient has signs of MS, she makes the initial diagnosis and refers the patient back to his neurologist or primary care doctor, where discussions about treatment and management can begin.
What makes Yale Medicine’s approach to MS imaging unique?
At Yale Medicine, MS imaging is a clinical practice and an area of active academic research that has crossover benefits for patients. Yale Medicine has the high-strength (3 Tesla) MRI machines for advanced clinical trials or therapies.
We help MS patients get the care they need through the Multiple Sclerosis & Other Inflammatory Brain Disease Program. Here, patients can easily see a doctor, have blood drawn, and get scans during the same visit. The Yale Medicine team is working to improve the way that doctors quantify, store and analyze the data gleaned from MS imaging.
The goal, Dr. Minja says, is “to be able to use computer algorithms to dig into the data in more detail than before, and to be able to see the white matter lesions, and then to quantify the burden of white matter lesions for the patient.”