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Updated: Apr 20, 2026
Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
Published on: December 18, 2016
Muscle velocity and inertial force from phase contrast MRI
Andrew L Wentland1, Emily J McWalter2, Saikat Pal3
1Department of Medical Physics, University of Wisconsin School of Medicine & Public Health, Madison, Wisconsin, USA.
Purpose:
To evaluate velocity waveforms in muscle and to create a tool and algorithm for computing and analyzing muscle inertial forces derived from 2D phase contrast (PC) magnetic resonance imaging (MRI).
Materials And Methods:
PC MRI was performed in the forearm of four healthy volunteers during 1 Hz cycles of wrist flexion-extension as well as in the lower leg of six healthy volunteers during 1 Hz cycles of plantarflexion-dorsiflexion. Inertial forces (F) were derived via the equation F = ma. The mass, m, was derived by multiplying voxel volume by voxel-by-voxel estimates of density via fat-water separation techniques. Acceleration, a, was obtained via the derivative of the PC MRI velocity waveform.
Results:
Mean velocities in the flexors of the forearm and lower leg were 1.94 ± 0.97 cm/s and 5.57 ± 2.72 cm/s, respectively, as averaged across all subjects; the inertial forces in the flexors of the forearm and lower leg were 1.9 × 10(-3) ± 1.3 × 10(-3) N and 1.1 × 10(-2) ± 6.1 × 10(-3) N, respectively, as averaged across all subjects.
Conclusion:
PC MRI provided a promising means of computing muscle velocities and inertial forces-providing the first method for quantifying inertial forces.
