TY - JOUR

T1 - Assessment of muscle function using hybrid PET/MRI

T2 - comparison of 18F-FDG PET and T2-weighted MRI for quantifying muscle activation in human subjects

AU - Haddock, Bryan

AU - Holm, Søren

AU - Poulsen, Jákup M.

AU - Enevoldsen, Lotte H.

AU - Larsson, Henrik B.W.

AU - Kjær, Andreas

AU - Suetta, Charlotte

PY - 2017

Y1 - 2017

N2 - Purpose: The aim of this study was to determine the relationship between relative glucose uptake and MRI T2 changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Methods: Ten young healthy recreationally active men (age 21 – 28 years) were injected with 18F-FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with 18F-FDG PET/MRI and muscle groups were evaluated for increases in 18F-FDG uptake and MRI T2 values. Results: A significant linear correlation between 18F-FDG uptake and changes in muscle T2 (R2 = 0.71) was found. for both small and large muscles and in voxel to voxel comparisons. Despite large intersubject differences in muscle recruitment, the linear correlation between 18F-FDG uptake and changes in muscle T2 did not vary among subjects. Conclusion: This is the first assessment of skeletal muscle activation using hybrid PET/MRI and the first study to demonstrate a high correlation between 18F-FDG uptake and changes in muscle T2 with physical exercise. Accordingly, it seems that changes in muscle T2 may be used as a surrogate marker for glucose uptake and lead to an improved insight into the metabolic changes that occur with muscle activation. Such knowledge may lead to improved treatment strategies in patients with neuromuscular pathologies such as stroke, spinal cord injuries and muscular dystrophies.

AB - Purpose: The aim of this study was to determine the relationship between relative glucose uptake and MRI T2 changes in skeletal muscles following resistance exercise using simultaneous PET/MRI scans. Methods: Ten young healthy recreationally active men (age 21 – 28 years) were injected with 18F-FDG while activating the quadriceps of one leg with repeated knee extension exercises followed by hand-grip exercises for one arm. Immediately following the exercises, the subjects were scanned simultaneously with 18F-FDG PET/MRI and muscle groups were evaluated for increases in 18F-FDG uptake and MRI T2 values. Results: A significant linear correlation between 18F-FDG uptake and changes in muscle T2 (R2 = 0.71) was found. for both small and large muscles and in voxel to voxel comparisons. Despite large intersubject differences in muscle recruitment, the linear correlation between 18F-FDG uptake and changes in muscle T2 did not vary among subjects. Conclusion: This is the first assessment of skeletal muscle activation using hybrid PET/MRI and the first study to demonstrate a high correlation between 18F-FDG uptake and changes in muscle T2 with physical exercise. Accordingly, it seems that changes in muscle T2 may be used as a surrogate marker for glucose uptake and lead to an improved insight into the metabolic changes that occur with muscle activation. Such knowledge may lead to improved treatment strategies in patients with neuromuscular pathologies such as stroke, spinal cord injuries and muscular dystrophies.

KW - Exercise

KW - Hybrid imaging

KW - Muscle

KW - PET/MRI

KW - T

U2 - 10.1007/s00259-016-3507-1

DO - 10.1007/s00259-016-3507-1

M3 - Journal article

C2 - 27604791

AN - SCOPUS:84986277765

VL - 44

SP - 704

EP - 711

JO - European Journal of Nuclear Medicine and Molecular Imaging

JF - European Journal of Nuclear Medicine and Molecular Imaging

SN - 1619-7070

IS - 4

ER -