title: Application of the McDonald MRI criteria in multiple sclerosis.
abstract: BACKGROUND
  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.
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Diagnostic Radiology, Singapore General Hospital, Singapore. gdrcll@sgh.com.sg
authors.forename: Ling Ling
authors.initials: LL
authors.lastname: Chan
authors.forename: Yih Yian
authors.initials: YY
authors.lastname: Sitoh
authors.forename: June
authors.initials: J
authors.lastname: Chong
authors.forename: Siew Ju
authors.initials: SJ
authors.lastname: See
authors.forename: Thirugnanam N
authors.initials: TN
authors.lastname: Umapathi
authors.forename: Shih Hui
authors.initials: SH
authors.lastname: Lim
authors.forename: Benjamin
authors.initials: B
authors.lastname: Ong
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000175:diagnosis* / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008485:Medical Audit; D009103:Multiple Sclerosis / Q000145:classification / Q000175:diagnosis*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012846:Singapore; D013119:Spinal Cord Injuries / Q000175:diagnosis / Q000473:pathology