title: One year activity on subtraction MRI predicts subsequent 4 year activity and progression in multiple sclerosis.
abstract: OBJECTIVE
  To investigate the predictive value of 1 year subtraction MRI (sMRI) on activity and progression over the next 4 years in early phase multiple sclerosis (MS). To compare sensitivity of sMRI and contrast enhanced MRI towards disease activity.
  
  
  METHODS
  The study was performed on 127 MS patients with brain MRI within 5 years of symptom onset (y0), after 1 year (y1) and after 5 years (y5). Measures of clinical (Expanded Disability Status Scale, relapse rate) and conventional MRI outcomes (brain parenchyma fraction (BPF); T2 lesion volume (T2LV); contrast enhancing lesions (CEL)) were available at all time points. sMRI was obtained from y1-y0, y5-y1 and y5-y0 image pairs and the number of new, enlarged, resolved and regressed lesions was counted.
  
  
  RESULTS
  One year lesion change measured by sMRI predicted sMRI lesion change (p<0.0001), BPF and T2LV (p<0.05) changes, as well as clinical relapse rate (p<0.02) in the subsequent 4 years. sMRI measures were retained in stepwise predictive models that included other candidate MRI predictors. Active lesions on sMRI over a 1, 4 or 5 year interval provided a more sensitive assessment of disease activity than number of CEL at y0, y1 and/or y5: 83%, 93% and 90% of patients without CEL showed sMRI activity during the y1-y0, y5-y1, and y5-y0 intervals.
  
  
  CONCLUSIONS
  sMRI is a feasible and sensitive tool for detecting MS activity and may provide an alternative to contrast enhanced MRI in clinical practice, particularly in cases where CEL are not available or inconclusive. Furthermore, sMRI metrics combined with conventional MRI outcomes (CEL, T2LV, BPF) can increase the prediction of longer term MRI activity and progression.
authors.affiliation: Department of Radiology, Center for Neurological Imaging, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: Maria
authors.initials: M
authors.lastname: Liguori
authors.forename: Dominik S
authors.initials: DS
authors.lastname: Meier
authors.forename: Peter
authors.initials: P
authors.lastname: Hildenbrand
authors.forename: Brian C
authors.initials: BC
authors.lastname: Healy
authors.forename: Tanuja
authors.initials: T
authors.lastname: Chitnis
authors.forename: Natalie F
authors.initials: NF
authors.lastname: Baruch
authors.forename: Samia J
authors.initials: SJ
authors.lastname: Khoury
authors.forename: Howard L
authors.initials: HL
authors.lastname: Weiner
authors.forename: Rohit
authors.initials: R
authors.lastname: Bakshi
authors.forename: Frederik
authors.initials: F
authors.lastname: Barkhof
authors.forename: Charles R G
authors.initials: CR
authors.lastname: Guttmann
mesh_terms: D000328:Adult; D001284:Atrophy; D001921:Brain / Q000473:pathology*; D004185:Disability Evaluation; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000175:diagnosis*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D013382:Subtraction Technique