Simultaneous Measurement of Perfusion and T2* in Calf Muscle at 7T with Dynamic Exercise using Radial Acquisition.

Abstract

Impairments in oxygen delivery and consumption can lead to muscle weakness and physical disability. Reduced blood flow, O2 delivery and consumption to the working muscle are likely to cause decline in muscle ability to sustain workloads. Perfusion is a measure of microvascular blood flow and provides information on nutrients delivery. T2* provides information about relative tissue oxygenation. Changes in these parameters following stress, such as exercise, can yield important information about imbalance between delivery and consumption. In this study, we implemented a novel MRI projection reconstruction technique to simultaneously quantify muscle perfusion and T2* at high magnetic field, 7T, and demonstrate assessment of spatial and temporal changes in these parameters within calf muscles both during and recovery from dynamic exercise. The high magnetic field offers significant improvement in the signal to noise ratio and the projection based reconstruction, which uses golden angle radial acquisition, offers very low sensitivity to bulk motion of the subject inside the MRI scanner.