Use of quantitative susceptibility mapping (QSM) in progressive multifocal leukoencephalopathy

J Neuroradiol. 2016 Feb;43(1):6-10. doi: 10.1016/j.neurad.2015.08.001. Epub 2015 Oct 23.


Background: Progressive multifocal leukoencephalopathy (PML) is an opportunistic demyelinating encephalopathy related to JC virus. Its characteristics on conventional brain MRI are well known and are important for the diagnosis.

Objective: To analyze SWI hypointensities recently described in U-fibers and cortex adjacent to the white matter lesions of PML.

Methods: Prospective study including four patients with an history of definite diagnosis of PML. Clinical data were collected retrospectively. Brain MRI exams were done on a 3T magnet, including FLAIR, T2 GRE sequences and SWI.

Results: Four males were included (mean age: 47 years, mean PML duration: 24.2 months). Immunosuppression was related to AIDS (n=2), natalizumab for multiple sclerosis (n=1), B-cell lymphoma treated by chemotherapeutic agents and rituximab (n=1). All patients had SWI hypointensities in cortex and/or U-fibers adjacent to the white matter lesions. QSM always suggested a paramagnetic effect.

Conclusion: SWI and T2 GRE hypointensities in cortex and U-fibers adjacent to the white matter lesions seem highly prevalent in PML, irrespective of the delay between PML onset and the MRI. QSM data suggest a paramagnetic effect.

Keywords: HIV infection; Magnetic resonance imaging; Multiple sclerosis; Progressive multifocal leukoencephalopathy.

MeSH terms

  • Brain / diagnostic imaging*
  • Brain / pathology*
  • Humans
  • Image Processing, Computer-Assisted
  • Leukoencephalopathy, Progressive Multifocal / diagnostic imaging*
  • Leukoencephalopathy, Progressive Multifocal / pathology*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Prospective Studies
  • Signal Processing, Computer-Assisted