Repeatability and sensitivity of the skeletal muscle response to in-scanner isometric exercise with vPIVOT MRI

Motivation: Quantification of the blood flow response to exercise provides insight into skeletal muscle health. Goal(s): To define the repeatability and sensitivity of perfusion changes in activated skeletal muscle in response to in-scanner isometric plantarflexion contraction in healthy individuals. Approach: vPIVOT MRI was used to measure perfusion throughout either two 70% maximum or a series of 30%, 50%, and 70% maximum isometric plantarflexion contractions. Intra-session repeatability and sensitivity of perfusion time course metrics to varied doses of exercise intensity were evaluated. Results: The area and timing to half recovery were both repeatable and sensitive to exercise-induced changes in activated muscles. Impact: Dynamic measurement of skeletal muscle perfusion in response to in-scanner exercise with vPIVOT MRI was repeatable and sensitive to varied exercise intensity in healthy adults. These results will help to facilitate comparison in future studies of patient populations.