Govind Nair1, Machelle T Pardue, Moon Kim, Timothy Q Duong. 1. Graduate School of Biomedical Science, University of Massachusetts Medical School and Worcester Polytechnic Institute, Worcester, Massachusetts, USA; Yerkes Imaging Center, Neuroscience Division, Emory University, Atlanta, Georgia, USA.
Abstract
PURPOSE: To use manganese-enhanced magnetic resonance imaging (MEMRI) at 25 × 25 × 800 μm(3) to image different retinal and vascular layers in the rat retinas. MATERIALS AND METHODS: Manganese-chloride was injected intraocularly in normal (n = 5) and Royal College of Surgeons (RCS, an model of photoreceptor degeneration) (n = 5) rats at postnatal day 90. MEMRI at 4.7 T was performed 24 hours later. MRI was repeated following intravenous Gd-DTPA in the same animals to highlight the vasculatures. Layer assignment and thickness were compared to histology. RESULTS: MEMRI 24 hours after intravitreal manganese-chloride injection revealed seven bands of alternating hyper- and hypointensities, corresponding histologically to the ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, photoreceptor-segment layer, and choroidal vascular layer. Intravenous Gd-DTPA-which does not cross the blood-retinal barrier and the retinal pigment epithelium-further enhanced the two layers bounding the retina, corresponding to the retinal and choroidal vascular layers, but not the avascular outer nuclear layer and the photoreceptor-segment layer. MEMRI of the RCS retinas revealed the loss of the outer plexiform layer, outer nuclear layer, and photoreceptor-segment layer. Histological analysis corroborated the MRI laminar assignments and thicknesses. CONCLUSION: Lamina-specific retinal structures neurodegenerative changes to structure in retinal diseases can be detected using MEMRI.
PURPOSE: To use manganese-enhanced magnetic resonance imaging (MEMRI) at 25 × 25 × 800 μm(3) to image different retinal and vascular layers in the rat retinas. MATERIALS AND METHODS:Manganese-chloride was injected intraocularly in normal (n = 5) and Royal College of Surgeons (RCS, an model of photoreceptor degeneration) (n = 5) rats at postnatal day 90. MEMRI at 4.7 T was performed 24 hours later. MRI was repeated following intravenous Gd-DTPA in the same animals to highlight the vasculatures. Layer assignment and thickness were compared to histology. RESULTS: MEMRI 24 hours after intravitreal manganese-chloride injection revealed seven bands of alternating hyper- and hypointensities, corresponding histologically to the ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, photoreceptor-segment layer, and choroidal vascular layer. Intravenous Gd-DTPA-which does not cross the blood-retinal barrier and the retinal pigment epithelium-further enhanced the two layers bounding the retina, corresponding to the retinal and choroidal vascular layers, but not the avascular outer nuclear layer and the photoreceptor-segment layer. MEMRI of the RCS retinas revealed the loss of the outer plexiform layer, outer nuclear layer, and photoreceptor-segment layer. Histological analysis corroborated the MRI laminar assignments and thicknesses. CONCLUSION: Lamina-specific retinal structures neurodegenerative changes to structure in retinal diseases can be detected using MEMRI.
Authors: F J Ollivier; D A Samuelson; D E Brooks; P A Lewis; M E Kallberg; A M Komáromy Journal: Vet Ophthalmol Date: 2004 Jan-Feb Impact factor: 1.644
Authors: S Wang; M P Villegas-Pérez; T Holmes; J M Lawrence; M Vidal-Sanz; N Hurtado-Montalbán; R D Lund Journal: Curr Eye Res Date: 2003-09 Impact factor: 2.424
Authors: Yi Zhang; Oscar San Emeterio Nateras; Qi Peng; Roman V Kuranov; Joseph M Harrison; Thomas E Milner; Timothy Q Duong Journal: Invest Ophthalmol Vis Sci Date: 2011-09-14 Impact factor: 4.799
Authors: Yi Zhang; Joseph M Harrison; Oscar San Emeterio Nateras; Steven Chalfin; Timothy Q Duong Journal: Doc Ophthalmol Date: 2013-02-14 Impact factor: 2.379