Document Detail


Blood flow MRI of the human retina/choroid during rest and isometric exercise.
MedLine Citation:
PMID:  22661466     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE: To investigate blood flow (BF) in the human retina/choroid during rest and handgrip isometric exercise using magnetic resonance imaging (MRI).
METHODS: Four healthy volunteers (25-36 years old) in multiple sessions (1-3) on different days. MRI studies were performed on a 3-Tesla scanner using a custom-made surface coil (7×5cm in diameter) at the spatial resolution of 0.5×0.8×6.0 mm. BF was measured using the pseudo-continuous arterial-spin-labeling technique with background suppression and turbo-spin-echo acquisition. During MRI, subjects rested for 1 minute followed by 1 minute of handgrip, repeating three times, while maintaining stable eye fixation on a target with cued eye blinks at the end of each data acquisition (every 4.6 seconds).
RESULTS: Robust BF of the unanesthetized human retina/choroid was detected. Basal BF in the posterior retina/choroid was 149±48 mL/100 mL/min with a mean heart rate of 60±5 beats per minute, mean arterial pressure of 78±5 mm Hg, ocular perfusion pressure of 67±4 mm Hg at rest (mean±SD, n=4 subjects). Handgrip significantly increased retina/choroid BF by 25%±7%, heart rate by 19%±8%, mean arterial pressure by 22%±5% (measured at the middle of the handgrip task), and ocular perfusion pressure by 25%±6% (averaged across the entire handgrip task) (P<0.01), but did not change intraocular pressure, arterial oxygen saturation, end-tidal CO2, and respiration rate (P>0.05).
CONCLUSIONS: This study demonstrates a novel MRI application to image quantitative BF of the human retina/choroid during rest and isometric exercise. Retina/choroid BF increases during brief handgrip exercise, paralleling increases in mean arterial pressure. Handgrip exercise changes ocular perfusion pressure free of potential drug side effect and can be done in the MRI scanner. MRI offers quantitative BF with large field of view without depth limitation, potentially providing insights into retinal pathophysiology.
Authors:
Yi Zhang; Oscar San Emeterio Nateras; Qi Peng; Carlos A Rosende; Timothy Q Duong
Related Documents :
1828226 - Lead, blood pressure, and cardiovascular disease in men and women.
19895756 - Recommendations for global hypertension monitoring and prevention.
18216206 - Individual differences in stressor-evoked blood pressure reactivity vary with activatio...
9386166 - Prospective prognostic assessment of blood pressure response during exercise in patient...
16461816 - Larger cell size in rabbits with heart failure increases myocardial conduction velocity...
9538286 - Measurement of intraocular pressure by both invasive and noninvasive techniques in rabb...
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2012-06-28
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  53     ISSN:  1552-5783     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  2012  
Date Detail:
Created Date:  2012-06-29     Completed Date:  2012-09-18     Revised Date:  2013-07-08    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  United States    
Other Details:
Languages:  eng     Pagination:  4299-305     Citation Subset:  IM    
Affiliation:
Research Imaging Institute, Department of Ophthalmology, University of Texas Health Science Center, San Antonio, TX 78229, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Adult
Choroid / blood supply,  physiology*
Exercise / physiology*
Female
Humans
Magnetic Resonance Angiography / methods*
Male
Reference Values
Regional Blood Flow / physiology*
Rest / physiology*
Retina / physiology*
Grant Support
ID/Acronym/Agency:
EY018855/EY/NEI NIH HHS; R01 EY014211/EY/NEI NIH HHS; R01 EY014211/EY/NEI NIH HHS; R01 EY018855/EY/NEI NIH HHS; UL1 RR025767/RR/NCRR NIH HHS; UL1 TR000149/TR/NCATS NIH HHS; UL1RR025767/RR/NCRR NIH HHS
Comments/Corrections

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  En face enhanced depth imaging optical coherence tomography of fibrovascular pigment epithelium deta...
Next Document:  Double concentric autofluorescence ring in NR2E3-p.G56R-linked autosomal dominant retinitis pigmento...