Magnetization transfer changes in the normal appering white matter precede the appearance of enhancing lesions in patients with multiple sclerosis

Authors

  • Dr Massimo Filippi MD,

    Corresponding author
    1. MS Biosignal Analysis Center, Department of Neurosciences, Scientific Institute Ospedale San Raffaele, University of Milan, Milan, Italy
    • MS Biosignal Analysis Center, Department of Neurology, Scientific Institute Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy
    Search for more papers by this author
  • Maria A. Rocca MD,

    1. MS Biosignal Analysis Center, Department of Neurosciences, Scientific Institute Ospedale San Raffaele, University of Milan, Milan, Italy
    Search for more papers by this author
  • Gianvito Martino MD,

    1. Unit of Neuroimmunology, Department of Neurosciences, Scientific Institute Ospedale San Raffaele, University of Milan, Milan, Italy
    Search for more papers by this author
  • Mark A. Horsfield PhD,

    1. Division of Medical Physics, University of Leicester, Leicester, UK
    Search for more papers by this author
  • Giancarlo Comi MD

    1. MS Biosignal Analysis Center, Department of Neurosciences, Scientific Institute Ospedale San Raffaele, University of Milan, Milan, Italy
    Search for more papers by this author

Abstract

Serial monthly magenetization transfer (MT) imaging was performed to evaluate whether a change of the normal appearing white matter (NAWM), which precedes the appearance of enhancing lesions, is seen in patients with multiple sclerosis (MS). Every 4 weeks for 3 months, 10 patients with relapsing-remitting MS were scanned with a T1-weighted sequence, 20 minutes after injection with 0.3 mmol/kg gadolinium-DTPA (Gd-DTPA). During each of the monthy sessions, MT and dual dual echo scans were also performed before Gd-DTPA injection. On coregistered images, the same slices but outside any present or future MR abnormality, and in enhancing lesions at the time of their apperance. Forty-eight new enhancing lesions with no corressponding abnormalities, the mean MTR in NAWM, measured from areas corresponding to future enhancing lesions, was significantly lower than the mean MTR in NAWM outside enhancing areas; the MTR decreased steadily as the time when the enhanced lesion approached. These results suggest that changes in the NAWM of patients with MS occur before lesions becomes evident on conventional MRI scans.

Ancillary