title: Use of quantitative susceptibility mapping (QSM) in progressive multifocal leukoencephalopathy.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Neurology, Montpellier University Hospital, Gui-de-Chauliac Hospital, 34295 Montpellier, France. Electronic address: clarisse.carra@gmail.com.
authors.forename: C
authors.initials: C
authors.lastname: Carra-Dalliere
authors.affiliation: Department of Neuroradiology, Montpellier University Hospital, Gui-de-Chauliac Hospital, 34295 Montpellier, France; Institut d'imagerie fonctionnelle humaine (I2FH), Montpellier University Hospital, 34295 Montpellier, France.
authors.forename: N
authors.initials: N
authors.lastname: Menjot de Champfleur
authors.affiliation: Department of Neuroradiology, Montpellier University Hospital, Gui-de-Chauliac Hospital, 34295 Montpellier, France; Institut d'imagerie fonctionnelle humaine (I2FH), Montpellier University Hospital, 34295 Montpellier, France.
authors.forename: J
authors.initials: J
authors.lastname: Deverdun
authors.affiliation: Department of Neurology, Montpellier University Hospital, Gui-de-Chauliac Hospital, 34295 Montpellier, France.
authors.forename: X
authors.initials: X
authors.lastname: Ayrignac
authors.affiliation: Department of Neurology, Montpellier University Hospital, Gui-de-Chauliac Hospital, 34295 Montpellier, France.
authors.forename: E
authors.initials: E
authors.lastname: Nerrant
authors.affiliation: Department of Infectious Diseases, Montpellier University Hospital, Saint-Éloi Hospital, 34295 Montpellier, France.
authors.forename: A
authors.initials: A
authors.lastname: Makinson
authors.affiliation: Department of Infectious Diseases, Montpellier University Hospital, Saint-Éloi Hospital, 34295 Montpellier, France.
authors.forename: M L
authors.initials: ML
authors.lastname: Casanova
authors.affiliation: Department of Neurology, Montpellier University Hospital, Gui-de-Chauliac Hospital, 34295 Montpellier, France.
authors.forename: P
authors.initials: P
authors.lastname: Labauge
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007968:Leukoencephalopathy, Progressive Multifocal / Q000000981:diagnostic imaging* / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted
keywords: HIV infection; Magnetic resonance imaging; Multiple sclerosis; Progressive multifocal leukoencephalopathy