Alterations of the proton-T2 time in relaxed skeletal muscle induced by passive extremity flexions. Rump, J.; Braun, J.R.; Papazoglou, S.; Taupitz, M.; and Sack, I. J Magn Reson Imaging, 23(4):541--546, Apr, 2006.
Paper doi abstract bibtex To demonstrate reciprocal changes of the apparent proton-T2 time in the biceps and triceps due to passive contraction and extension of the muscle fibers.The contraction state of the upper arm muscles of six healthy volunteers was passively changed by alternating the forearm position between the straight-arm position and an elbow flexion of 90 degrees. The relaxation of the muscle during passive contraction and extension was measured with the use of muscle electromyography (EMG) experiments. Spin-echo (SE) MRI with increasing echo times (TEs) of 12-90 msec was used to acquire the averaged signal decay of the segmented biceps and triceps. The apparent T2 was deduced using monoexponential least-square fitting.The median T2 alterations in biceps and triceps among all volunteers were found to be 1.2 and -1.3 msec in the straight and bent forearm positions, respectively. The confidence intervals (0.5 to 1.7 msec in biceps, and -2.6 to -1.1 msec in triceps) clearly indicate that proton-T2 in MR images is significantly (P < 0.05) prolonged with muscle contraction.The observed increase of the proton-T2 time was correlated with a passive contraction of skeletal muscle fibers. This passive effect can be attributed to changes in the intracellular water mobility corresponding to the well-known "active" T2 increase that occurs after stimulation of muscle.
@article{ Rump2006,
author = {Rump, Jens and Braun, J�rgen and Papazoglou, Sebastian and Taupitz,
Matthias and Sack, Ingolf},
title = {Alterations of the proton-T2 time in relaxed skeletal muscle induced
by passive extremity flexions.},
journal = {J Magn Reson Imaging},
year = {2006},
volume = {23},
pages = {541--546},
number = {4},
month = {Apr},
abstract = {To demonstrate reciprocal changes of the apparent proton-T2 time in
the biceps and triceps due to passive contraction and extension of
the muscle fibers.The contraction state of the upper arm muscles
of six healthy volunteers was passively changed by alternating the
forearm position between the straight-arm position and an elbow flexion
of 90 degrees. The relaxation of the muscle during passive contraction
and extension was measured with the use of muscle electromyography
(EMG) experiments. Spin-echo (SE) MRI with increasing echo times
(TEs) of 12-90 msec was used to acquire the averaged signal decay
of the segmented biceps and triceps. The apparent T2 was deduced
using monoexponential least-square fitting.The median T2 alterations
in biceps and triceps among all volunteers were found to be 1.2 and
-1.3 msec in the straight and bent forearm positions, respectively.
The confidence intervals (0.5 to 1.7 msec in biceps, and -2.6 to
-1.1 msec in triceps) clearly indicate that proton-T2 in MR images
is significantly (P < 0.05) prolonged with muscle contraction.The
observed increase of the proton-T2 time was correlated with a passive
contraction of skeletal muscle fibers. This passive effect can be
attributed to changes in the intracellular water mobility corresponding
to the well-known "active" T2 increase that occurs after stimulation
of muscle.},
doi = {10.1002/jmri.20534},
institution = {Institute of Radiology, Charit�-University Medicine Berlin, Berlin,
Germany.},
keywords = {Humans; Image Processing, Computer-Assisted; Isometric Contraction;
Magnetic Resonance Imaging, methods; Muscle Contraction, physiology;
Muscle, Skeletal, physiology; Prone Position; Protons; Statistics,
Nonparametric; Upper Extremity, physiology},
language = {eng},
medline-pst = {ppublish},
owner = {Heiko},
pmid = {16514596},
timestamp = {2013.07.26},
url = {http://dx.doi.org/10.1002/jmri.20534}
}