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Exercise-related changes in aortic flow measured with spiral echo-planar MR velocity mapping
R H Mohiaddin1, P D Gatehouse, D N Firmin
1Magnetic Resonance Unit, Royal Brompton Hospital, London, England.
Journal of Magnetic Resonance Imaging : JMRI
|March 1, 1995
Summary
Spiral echo-planar magnetic resonance (MR) velocity mapping revealed significant increases in descending thoracic aorta blood flow after dynamic exercise. This technique accurately measured exercise-induced hemodynamic changes in healthy volunteers.
Area of Science:
- Cardiovascular Physiology
- Magnetic Resonance Imaging
Background:
- Assessing exercise-induced hemodynamic changes in the aorta is crucial for understanding cardiovascular function.
- Magnetic resonance (MR) imaging offers non-invasive methods for flow quantification.
Purpose of the Study:
- To evaluate exercise-related changes in descending thoracic aorta blood flow using spiral echo-planar MR velocity mapping.
- To assess the feasibility and reproducibility of this MR technique in healthy volunteers.
Main Methods:
- Utilized spiral echo-planar MR velocity mapping on a 0.5-T imager with electrocardiographic triggering.
- Measured aortic flow at rest and immediately after supine dynamic exercise in 10 healthy volunteers.
- Acquired data over four heartbeats with a temporal resolution of 50 msec.
Main Results:
- Resting mean aortic flow was 41 mL/beat, increasing to 57 mL/beat after exercise (P < .001).
- Peak aortic flow increased from 107 mL/sec to 158 mL/sec post-exercise (P < .001).
- Time to peak flow significantly decreased from 175 msec to 115 msec after exercise (P < .001).
Conclusions:
- Spiral echo-planar MR velocity mapping is a reproducible technique for measuring acute exercise-induced changes in thoracic aortic blood flow.
- Exercise significantly increases aortic flow volume and velocity while reducing the time to peak flow.