MRI in methotrexate-related leukoencephalopathy: Disseminated necrotising leukoencephalopathy in comparison with mild leukoencephalopathy

Neuroradiology. 2003 Jul;45(7):493-7. doi: 10.1007/s00234-003-0983-3. Epub 2003 May 22.


We report two fatal cases of methotrexate (MTX)-induced disseminated necrotising leukoencephalopathy (DNL) in which MRI was repeated from the onset. Initial T2-weighted images showed multiple areas of high signal, mainly in deep cerebral white matter, which on follow-up, spread and coalesced to involve the entire white matter. Small irregular low-signal foci on T2-weighted images were seen within the high-signal lesions. Multiple areas of contrast enhancement corresponded to these low-signal foci. The condition of both patients deteriorated and they died. We compared their MRI findings with those of seven patients with mild MTX-related leukoencephalopathy, six of whom were asymptomatic; one had transient neurological symptoms. They showed no contrast enhancement, but rather mild-to-moderate diffuse high signal in deep white matter, which later disappeared. These findings suggest that multiple low-signal foci on T2-weighted images with contrast enhancement may be characteristic of DNL, and that contrast-enhanced imaging is useful to differentiate this condition from mild leukoencephalopathy.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Brain Diseases / diagnosis
  • Child
  • Child, Preschool
  • Drug-Related Side Effects and Adverse Reactions*
  • Encephalomyelitis, Acute Disseminated / diagnosis
  • Encephalomyelitis, Acute Disseminated / pathology
  • Female
  • Follow-Up Studies
  • Humans
  • Image Enhancement
  • Leukoencephalopathy, Progressive Multifocal / chemically induced*
  • Leukoencephalopathy, Progressive Multifocal / diagnosis*
  • Magnetic Resonance Imaging*
  • Male
  • Methotrexate / adverse effects*
  • Radiotherapy, Adjuvant / adverse effects


  • Methotrexate