title: Progressive multifocal leukoencephalopathy and human immunodeficiency virus-associated white matter lesions in AIDS: magnetization transfer MR imaging.
abstract: OBJECTIVE
  To determine the magnetization transfer features of progressive multifocal leukoencephalopathy (PML) and human immunodeficiency virus (HIV)-associated white matter lesions (WML) (hereafter, HIV-WML) on magnetic resonance (MR) images obtained in patients with acquired immunodeficiency syndrome (AIDS).
  
  
  METHODS
  Conventional MR imaging and magnetization transfer MR imaging were performed in 21 AIDS patients with 42 areas of white matter hyperintensity on MR images (13 patients had 25 PML lesions, eight patients had 17 WML). The magnetization transfer ratio was calculated for each lesion.
  
  
  RESULTS
  Compared with normal-appearing white matter (magnetization transfer ratio = 47.9%), both PML and HIV-WML showed reduced magnetization transfer ratio. The magnetization transfer ratio was significantly lower in PML lesions (magnetization transfer ratio = 26.1%) than in HIV-WML (magnetization transfer ratio = 38.0%, P < .0001), and there was no overlap in the magnetization transfer ratio between PML lesions and HIV-WML. The separation in magnetization transfer ratio between the two lesion types was valid for lesion as small as 0.5 cm2.
  
  
  CONCLUSIONS
  The larger reduction in magnetization transfer ratio for PML lesions is most likely due to demyelination, whereas the reduction in HIV-WML may be associated primarily with gliosis. PML lesions appear to cause strong reductions in magnetization transfer ratio early in the course of disease. Magnetization transfer MR imaging is a noninvasive tool that improves the differentiation between PML and HIV-WML in patients with AIDS.
authors: Department of Radiology, Harbor-UCLA Medical Center, Torrance 90502, USA.
authors: T
authors: T
authors: Ernst
authors: L
authors: L
authors: Chang
authors: M
authors: M
authors: Witt
authors: I
authors: I
authors: Walot
authors: H
authors: H
authors: Aronow
authors: M
authors: M
authors: Leonido-Yee
authors: E
authors: E
authors: Singer
mesh_terms: D015526:AIDS Dementia Complex / Q000473:pathology*; D000328:Adult; D001921:Brain / Q000473:pathology*; D003937:Diagnosis, Differential; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007968:Leukoencephalopathy, Progressive Multifocal / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D011446:Prospective Studies