What MRI machine and protocol best detects any changes in lesions or enhancing lesions?
I'm feeling physical changes, but the MRI report shows no changes and I want to be informed.
Thank you so much for answering my question.
An MRI done to detect a change in disease state is only as good as the last MRI scan your received. Otherwise you are trying to compare apples to oranges. Let me explain.
Imagine you obtained the highest resolution MRI scan available with the thinnest possible slices and all your brain tissue is imaged (we call this a volumetric image acquisition). This scan may show 60 discrete lesions with a resolution allowing you to confidently identify lesions as small as 1 mm diameter in the cortex. This will not help you if the prior MRI was obtained on a conventional 1.5 or even a 3.0 Tesla scanner with slice thickness of 3 to 5 mm and a gap between slices. The conventional scan may only identify 20 lesions and any comparison of the scans may suggest, inappropriately, that you suddenly developed 40 new lesions !! Other technical factors can make comparisons difficult even when the scans are obtained on the same scanner.
This is why we recommend all our patients obtain a new baseline study on a 3 Tesla MRI scanner using volumetric 3-dimensional imaging with pulse sequences allowing us to perform automated registration and segmentation for comparisons of scans between time points. Unfortunately, few centers have this capability at present.
For the time being it is best for you to obtain repeat MRIs on the same scanner used previously using the same imaging protocol and slice orientation for all scans.
Even when this is done, changes on MRI do not correlate one to one with changes in symptoms or changes examination. For over three decades, we have referred to this phenomenon as the clinical radiological paradox.
In many ways MRI findings and changes on MRIs over short intervals (1-2 years) do a better job of predicting clinically meaningful changes in neurological function that may occur in the future
Gadolinium enhancement on an MRI represents new breakdown of the blood brain barrier and is associated with acute inflammation. There is not a one to one relationship between relapses and gadolinium enhancement although enhancement may flare up around periods of relapses. This gadolinium enhancement does not correlate well with future disability in untreated patients but does correlate well with future lack of response to a disease modifying therapies if the enhancement persists on future scans at least 6 months after starting the disease modifying therapy. Highly active disease modifying therapies (such as Tysabri, Alemtuzumab, Rituximab and Ocrelizumab) virtually eliminate gadolinium enhancing lesions and are often not obtained after an individual is stable on a highly active disease modifying therapy for more than a year. The vast majority of enhancing lesions persist as T2 bright spots without gadolinium and will be detected as new interval lesions on a later scan.
Revere (Rip) Kinkel MD
Director of the Multiple Sclerosis Program
Professor of Clinical Neurosciences
University of California San Diego