Magnetic resonance imaging of the retina: From mice to men

Duong, Timothy Q.

doi:10.1002/mrm.24797

Cited by 24 publications

(18 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In section A, we describe the general features of the lightevoked changes in intraretinal 1/T1r in untreated or manganese-treated mice; manganese imparts functional information about calcium channels as measured by manganese-enhanced MRI (MEMRI), the imaging modality of choice when performing studies of retinal ion activity (17,18). The MRI axial resolution (in the present mouse study, 21.9 mm) used in all sections herein is sufficient to generate very high spatial resolution functional maps of central retina, as demonstrated in many publications from our group and others (19)(20)(21)(22)(23)(24)(25). In section B, we examine the sensitivity of 1/T1r MRI to purified tet-ARR1 in solution and in transgenic mice in vivo (11,26).…”

mentioning

confidence: 65%

Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light‐evoked translocation in vivo

Berkowitz¹,

Gorgis²,

Patel

et al. 2014

FASEB j.

View full text Add to dashboard Cite

Rod tetrameric arrestin 1 (tet-ARR1), stored in the outer nuclear layer/inner segments in the dark, modulates photoreceptor synaptic activity; light exposure stimulates a reduction via translocation to the outer segments for terminating G-protein coupled phototransduction signaling. Here, we test the hypothesis that intraretinal spin-lattice relaxation rate in the rotating frame (1/T1r), an endogenous MRI contrast mechanism, has high potential for evaluating rod tet-ARR1 and its reduction via translocation. Dark-and light-exposed mice (null for the ARR1 gene, overexpressing ARR1, diabetic, or wild type with or without treatment with Mn 2+ , a calcium channel probe) were studied using 1/T1r MRI. Immunohistochemistry and single-cell recordings of the retinas were also performed. In wild-type mice with or without treatment with Mn 2+ , 1/T1r of avascular outer retina (64% to 72% depth) was significantly (P < 0.05) greater in the dark than in the light; a significant (P < 0.05) but opposite pattern was noted in the inner retina (<50% depth). Light-evoked outer retina D1/T1r was absent in ARR1-null mice and supernormal in overexpressing mice. In diabetic mice, the outer retinal D1/T1r pattern suggested normal darkto-light tet-ARR1 translocation and chromophore content, conclusions confirmed ex vivo. Light-stimulated D1/ T1r in inner retina was linked to changes in blood volume. Our data support 1/T1r MRI for noninvasively assessing rod tet-ARR1 and its reduction via protein translocation, which can be combined with other metrics of retinal function in vivo.-Berkowitz, B. A., Gorgis, J., Patel, A., Baameur, F., Gurevich, V. V., Craft, C. M., Kefalov, V. J., Roberts, R. Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light-evoked translocation in vivo. FASEB J. 29, 554-564 (2015). www.fasebj.org

show abstract

mentioning

confidence: 65%

Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light‐evoked translocation in vivo

Berkowitz¹,

Gorgis²,

Patel

et al. 2014

FASEB j.

View full text Add to dashboard Cite

show abstract

“…2) (Chan et al, 2012;Chen et al, 2008Chen et al, , 2011Duong, 2014;Wang et al, 2011). This 23.4 mm resolution is important because it allows for the collection of MRI data that can distinguish inner retina structure/ function from that in the outer retina aided by the 200 mm thick retina having a well-defined laminar structure (Berkowitz et al, 2009a(Berkowitz et al, , 2012a(Berkowitz et al, , 2007dBissig and Berkowitz, 2011).…”

Section: Breakthroughmentioning

confidence: 97%

MRI of rod cell compartment-specific function in disease and treatment in vivo

Berkowitz

Bissig

Roberts

2016

Progress in Retinal and Eye Research

View full text Add to dashboard Cite

Rod cell oxidative stress is a major pathogenic factor in retinal disease, such as diabetic retinopathy (DR) and retinitis pigmentosa (RP). Personalized, non-destructive, and targeted treatment for these diseases remains elusive since current imaging methods cannot analytically measure treatment efficacy against rod cell compartment-specific oxidative stress in vivo. Over the last decade, novel MRI-based approaches that address this technology gap have been developed. This review summarizes progress in the development of MRI since 2006 that enables earlier evaluation of the impact of disease on rod cell compartment-specific function and the efficacy of anti-oxidant treatment than is currently possible with other methods. Most of the new assays of rod cell compartment-specific function are based on endogenous contrast mechanisms, and this is expected to facilitate their translation into patients with DR and RP, and other oxidative stress-based retinal diseases.

show abstract

“…Although functional MRI has been explored for quantifying ocular sO 2 (Berkowitz and Wilson, 1995; Duong, 2014), the optical methods have played a dominant role (Harris et al, 2003). The physical basis of almost all the optical methods is the distinctive molar extinction coefficients of oxygenated and deoxygenated hemoglobin across a wide optical spectral range (Friebel et al, 2006; Hammer et al, 1995), which leads to different optical attenuation in blood with different sO 2 levels.…”

Section: Approaches To Retinal Oxygenmentioning

confidence: 99%

Retinal oxygen: from animals to humans

Linsenmeier

Zhang

2017

Progress in Retinal and Eye Research

184

150

View full text Add to dashboard Cite

This article discusses retinal oxygenation and retinal metabolism by focusing on measurements made with two of the principal methods used to study O2 in the retina: measurements of PO2 with oxygen-sensitive microelectrodes in vivo in animals with a retinal circulation similar to that of humans, and oximetry, which can be used non-invasively in both animals and humans to measure O2 concentration in retinal vessels. Microelectrodes uniquely have high spatial resolution, allowing the mapping of PO2 in detail, and when combined with mathematical models of diffusion and consumption, they provide information about retinal metabolism. Mathematical models, grounded in experiments, can also be used to simulate situations that are not amenable to experimental study. New methods of oximetry, particularly photoacoustic ophthalmoscopy and visible light optical coherence tomography, provide depth-resolved methods that can separate signals from blood vessels and surrounding tissues, and can be combined with blood flow measures to determine metabolic rate. We discuss the effects on retinal oxygenation of illumination, hypoxia and hyperoxia, and describe retinal oxygenation in diabetes, retinal detachment, arterial occlusion, and macular degeneration. We explain how the metabolic measurements obtained from microelectrodes and imaging are different, and how they need to be brought together in the future. Finally, we argue for revisiting the clinical use of hyperoxia in ophthalmology, particularly in retinal arterial occlusions and retinal detachment, based on animal research and diffusion theory.

show abstract

Magnetic resonance imaging of the retina: From mice to men

Cited by 24 publications

References 53 publications

Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light‐evoked translocation in vivo

Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light‐evoked translocation in vivo

MRI of rod cell compartment-specific function in disease and treatment in vivo

Retinal oxygen: from animals to humans

Contact Info

Product

Resources

About