Introduction: The aim of this study was to assess the sensitivity of McDonald’s magnetic resonance imaging (MRI) criteria for the diagnosis of multiple sclerosis (MS) in a group of Asian patients diagnosed with clinically definite MS, based on lesion characterisation on MRI scans. Materials and Methods: Forty-nine patients from 3 major neurological institutions were classified as having Asian- or Western-type MS based on clinical assessment. Each MRI scan was reviewed by 2 neuroradiologists for the presence and characteristics of brain and spinal lesions. The McDonald’s MRI criteria were then applied and its sensitivity evaluated. Results: Nine patients were excluded, leaving 34 females and 6 males who were dominantly Chinese (90%), with a mean age of 36.2 years. The MRI brain and spinal findings were detailed and tabulated. Statistically significant differences (P <0.01) in MRI brain findings and sensitivity of McDonald’s MRI criteria were found between our Asian- and Western-type MS patients. The diagnostic yield of McDonald’s MRI criteria increased by 20% when we substituted a cord for a brain lesion, and applied the substitution for enhancing cord lesions as well. Conclusion: The diagnosis is more likely to be made when using McDonald MRI criteria based on brain findings, in a patient who presents clinically with Western-type MS. The provision for substitution of “one brain for a spinal lesion” is helpful in Asian-type MS, where there is preponderance of spinal lesion load. Our findings suggest that minor modifications in the interpretation of McDonald’s MRI criteria have significant impact on the diagnosis in patients clinically presenting as Asian-type MS, with potential bearing on their subsequent management.
Since its advent in 1982, magnetic resonance imaging (MRI) has become an important component in the evaluation of multiple sclerosis (MS). MRI is a highly sensitive tool for MS, with 95% patients with clinically definite MS (CDMS) demonstrating brain abnormalities.1 However, MRI is also known to be low in specificity, with a variety of diseases causing MS-like abnormalities in the brain.2 Over the years, various composite MR features have been proposed1,3,4 to enhance the specificity of MRI for the diagnosis of MS. Most recently, the International Panel on MS Diagnosis5 has proposed using MRI as an objective tool to document dissemination in time and space, and directly incorporating the MRI findings into the overall diagnostic scheme for MS. Their proposed McDonald’s MRI criteria were chiefly based on a modification of Barkhof’s criteria4 and recommendations by Tintore et al.6
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