MRI in the Diagnosis of MS
Fred D. Lublin, MD: A larger diagnosis with MRI [magnetic resonance imaging] scans started in, what, 1981, at your institution Dr Calabresi?
Peter A. Calabresi, MD: MRI has certainly revolutionized our ability to study the disease and diagnose it. It’s part of the McDonald Criteria, as we just discussed. I, of course, am an advocate of getting an MRI at the time of diagnosis. And I agree with Pat that one has to get the full spinal cord down to the conus. Sometimes we will even look at the roots and the lumbosacral to look for other explanations for lower extremity problems.
I think that as Stephen said, it’s a real issue though, this issue of nonspecificity. I’m excited about some of the new techniques such as central vein sign, which may add a layer of specificity to some of these small white spots that we would otherwise, or some people might call them, demyelinating. And with some of the newer techniques we are seeing truly cortical lesions, although I think we’ll still have to be very careful about being confident that those are real and not artifactual.
Fred D. Lublin, MD: Are you using central vein sign now?
Peter A. Calabresi, MD: We are not allowed to use it on our clinical scanner. Apparently it’s not an FDA approved pulse sequence acquisition. So if we happen to get it for a research protocol, we look at it, but we’re not allowed to have it on our clinical scanner.
Patricia K. Coyle, MD: Could I say, why haven’t we been able to get our act together to standardize how we do MRI scans for MS [multiple sclerosis]? Wouldn’t that be helpful? We haven’t even been able to do that.
Fred D. Lublin, MD: CMSC [The Consortium of Multiple Sclerosis Centers] every couple of years puts out a reasonable recommendation on what’s done, but for the most part, we don’t own the scanners. Right? At academic centers there’s a radiology department that thinks they own them.
Peter A. Calabresi, MD: Ellen Mowry, MD, at our center took the CMSC pulse sequence acquisition and went to RadNet Inc, which is the national network, and asked them if they would consider using this. And they accepted, so they are starting to now use a standardized protocol for MRI. It hasn’t been a widespread application, but I think it’s a start. I think we need to advocate for that.
Stephen C. Krieger, MD: In general, as the software gets better we’re able to see things on scans that are more detailed than what we could see 5 or 10 years ago, and I do think it’s important to make sure that what we’re doing in academic settings and in research can be applied broadly. Remembering, too, that the McDonald Criteria, the way that those lesions are looked at was performed on 1.5 tesla MRI scans. We can see more than that now. But I think upgrading hardware is difficult in the community, difficult across many sites. Upgrading software is easier. I’m hopeful that things like central vein, which is really a software upgrade that just needs to get approved and rolled out, might be easier for all-comers to be able to have performed, as opposed to let’s say a 3T or 7T MRI, which is going to be incredibly expensive and cumbersome to try to implement broadly.
Fred D. Lublin, MD: What’s the best sequence for a central vein?
Stephen C. Krieger, MD: Well, there are sequences to allow for layering of the FLAIR [fluid-attenuated inversion recovery] and a susceptibility-weighted sequence, to look and see the area within the lesion that’s actually the vein itself. It’s a nice example of being able to see something with modern technology that we’ve known has been true for a hundred years, that there are veins within these lesions. It’s just they’ve been basically hiding in plain sight with our standard T2 or T2-FLAIR imaging.
