Researchers at the University of Nottingham and Nottingham University Hospitals NHS Trust have successfully tested a new way of using clinical MRI scanners to look for evidence of multiple sclerosis (MS) in the brain.
Multiple sclerosis is a chronic neurological condition that affects roughly 100,000 people in the UK and presents with a wide range of symptoms. Diagnosis can be difficult because symptoms vary between patients and disease progression differs widely. MRI has long been a key diagnostic tool because it detects white matter lesions in the brain, but not all white matter lesions signal MS. Distinguishing MS lesions from other types of white matter changes remains a clinical challenge.
The Nottingham research team has shown that a routine clinical MRI scanner can be used with a specific T2-weighted protocol (in this study the 3-T T2*-weighted technique was employed) to identify lesions in the brain’s white matter that are centred on a vein. This “central vein sign” is a known indicator of MS and, when detectable on clinical scanners, may help clinicians distinguish MS-related lesions from microangiopathic or other non-MS white matter lesions.
Dr Nikos Evangelou, who led the study, explained that while ultra-high-field research MRI systems (such as 7-T scanners) have previously demonstrated the value of assessing the presence of central veins in lesions, those systems are not widely available in routine clinical practice. The Nottingham team therefore tested whether a single scan performed on a standard NHS hospital scanner could reliably separate patients with MS from those with other types of white matter lesions. Their results indicate that this approach could supplement existing diagnostic methods.
The prospective study included 40 patients recruited from the neurology outpatient department at Nottingham University Hospitals NHS Trust. The investigators first scanned a test cohort of 10 patients with confirmed MS and 10 patients with non-MS white matter lesions. Scans were anonymised and reviewed blind to clinical information. From this analysis the researchers developed a simple diagnostic rule based on the proportion of lesions showing a central vein.
Within the test cohort, every patient with MS had central veins visible in more than 45% of their brain lesions, while patients with non-MS lesions showed central veins in fewer than 45% of lesions. The team then applied this simple threshold to a validation cohort of 20 additional patients (13 with MS and 7 with other lesions). A blinded observer using the same rules correctly categorised all validation patients, and each scan took less than two minutes to assess.
This technique is significant because, among patients referred to specialist MS centres with suspected disease, fewer than half are ultimately diagnosed with MS. Improving the specificity of MRI-based evaluation would help avoid unnecessary treatments, accelerate accurate diagnosis for people with MS, and reduce diagnostic uncertainty for many patients.
The Nottingham group has begun a follow-up study focused on patients with genuine diagnostic uncertainty and plans to expand recruitment to additional UK centres so more patients can take part. The investigators have presented early findings internationally, and similar studies are being planned elsewhere based on these results. Researchers involved say it may be possible within a relatively short timeframe to confirm whether this clinical MRI approach consistently improves diagnostic accuracy.
Source: Emma Rayner – University of Nottingham
Image credit: Image adapted from the University of Nottingham press release
Original research: Mistry N., Abdel-Fahim R., Samaraweera A., Mougin O., Tallantyre E., Tench C., Jaspan T., Morris P., Morgan P. S., and Evangelou N. “Imaging central veins in brain lesions with 3-T T2*-weighted magnetic resonance imaging differentiates multiple sclerosis from microangiopathic brain lesions.” Multiple Sclerosis Journal. Published online December 10, 2015. doi:10.1177/1352458515616700
Abstract (summary)
Background: White matter lesions detected on brain MRI can have multiple causes. Although many are microangiopathic, demyelinating processes such as multiple sclerosis are an important and distinct cause. Conventional MRI sequences cannot always differentiate between these pathologies, but the presence of a central vein within lesions has emerged as a distinguishing feature on high-field MRI.
Objective: To determine whether 3-T T2*-weighted MRI performed on a clinical scanner can differentiate MS lesions from microangiopathic white matter lesions.
Methods: Forty patients were prospectively studied. An initial test cohort (10 MS, 10 non-MS) underwent 3-T T2*-weighted brain MRI; anonymised scans were analysed blinded to clinical data and a diagnostic rule was devised. The rule was then applied to a validation cohort of 20 patients (13 MS, 7 non-MS) by a blinded observer.
Results: In the test cohort, patients with MS had central veins visible in more than 45% of lesions, whereas patients with microangiopathic lesions showed central veins in fewer than 45% of lesions. Applying this threshold to the validation cohort correctly classified all patients.
Conclusion: 3-T T2*-weighted clinical MRI can distinguish perivenous MS lesions from microangiopathic lesions. Implemented in routine practice, this technique could supplement existing diagnostic algorithms and reduce uncertainty in the assessment of white matter lesions.