title: Detection of neuritic plaques in Alzheimer's disease by magnetic resonance microscopy.
abstract: Magnetic resonance microscopy (MRM) theoretically provides the spatial resolution and signal-to-noise ratio needed to resolve neuritic plaques, the neuropathological hallmark of Alzheimer's disease (AD). Two previously unexplored MR contrast parameters, T2* and diffusion, are tested for plaque-specific contrast to noise. Autopsy specimens from nondemented controls (n = 3) and patients with AD (n = 5) were used. Three-dimensional T2* and diffusion MR images with voxel sizes ranging from 3 x 10(-3) mm(3) to 5.9 x 10(-5) mm(3) were acquired. After imaging, specimens were cut and stained with a microwave king silver stain to demonstrate neuritic plaques. From controls, the alveus, fimbria, pyramidal cell layer, hippocampal sulcus, and granule cell layer were detected by either T2* or diffusion contrast. These structures were used as landmarks when correlating MRMs with histological sections. At a voxel resolution of 5.9 x 10(-5) mm(3), neuritic plaques could be detected by T2*. The neuritic plaques emerged as black, spherical elements on T2* MRMs and could be distinguished from vessels only in cross-section when presented in three dimension. Here we provide MR images of neuritic plaques in vitro. The MRM results reported provide a new direction for applying this technology in vivo. Clearly, the ability to detect and follow the early progression of amyloid-positive brain lesions will greatly aid and simplify the many possibilities to intervene pharmacologically in AD.
authors.affiliation: Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA. hb@orion.mc.duke.edu
authors.forename: H
authors.initials: H
authors.lastname: Benveniste
authors.forename: G
authors.initials: G
authors.lastname: Einstein
authors.forename: K R
authors.initials: KR
authors.lastname: Kim
authors.forename: C
authors.initials: C
authors.lastname: Hulette
authors.forename: G A
authors.initials: GA
authors.lastname: Johnson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology*; D004396:Coloring Agents; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008875:Middle Aged; D058225:Plaque, Amyloid / Q000473:pathology*; D011522:Protons
chemical_list: D004396:Coloring Agents; D011522:Protons