Dynamic intravoxel incoherent motion imaging of skeletal muscle at rest and after exercise

Abstract

The purpose of this work was to demonstrate the feasibility of intravoxel incoherent motion imaging (IVIM) for non-invasive quantification of perfusion and diffusion effects in skeletal muscle at rest and following exercise. After IRB approval, eight healthy volunteers underwent diffusion-weighted MRI of the forearm at 3 T and eight different b values between 0 and 500 s/mm(2) with a temporal resolution of 57 s per dataset. Dynamic images were acquired before and after a standardized handgrip exercise. Diffusion (D) and pseudodiffusion (D*) coefficients as well as the perfusion fraction (FP ) were measured in regions of interest in the flexor digitorum superficialis and profundus (FDS/FDP), brachioradialis, and extensor carpi radialis longus and brevis muscles by using a multi-step bi-exponential analysis in MATLAB. Parametrical maps were calculated voxel-wise. Differences in D, D*, and FP between muscle groups and between time points were calculated using a repeated measures analysis of variance with post hoc Bonferroni tests. Mean values and standard deviations at rest were the following: D*, 28.5 ± 11.4 × 10(-3) mm(2) /s; FP , 0.03 ± 0.01; D, 1.45 ± 0.09 × 10(-3) mm(2) /s. Changes of IVIM parameters were clearly visible on the parametrical maps. In the FDS/FDP, D* increased by 289 ± 236% (p < 0.029), FP by 138 ± 58% (p< 0.01), and D by 17 ± 9% (p < 0.01). A significant increase of IVIM parameters could also be detected in the brachioradialis muscle, which however was significantly lower than in the FDS/FDP. After 20 min, all parameters were still significantly elevated in the FDS/FDP but not in the brachioradialis muscle compared with the resting state. The IVIM approach allows simultaneous quantification of muscle perfusion and diffusion effects at rest and following exercise. It may thus provide a useful alternative to other non-invasive methods such as arterial spin labeling. Possible fields of interest for this technique include perfusion-related muscle diseases, such as peripheral arterial occlusive disease.

Effects of perfusion on DTI and DKI estimates in the skeletal muscle

“…Simulated data for Experiment I was generated using Equation [] and two biologically feasible values of f : 1) f = 5 % , that is, the average value we observed in vivo (see the MRI experiments section); and 2) f = 15%, that is, the highest value observed in our invivo data in muscle. Noteworthy, these values are in line with previous studies . Simulations for Experiment II were generated using Equation [] and four sets of biologically feasible values of f and K : 1) f = 5% and K = 3; 2) f = 15% and K = 3; 3) f = 5% and K = 3.5; and 4) and f = 15% and K = 3.5.…”

Skeletal muscle quantitative nuclear magnetic resonance imaging and spectroscopy as an outcome measure for clinical trials (part II)

“…В зависимости от схемы кодирования диффузии в скелетных мышцах также могут быть оп-ределены параметры, связанные с перфузией и микро-циркуляцией [44,181]. Хотя большинство DWI в скелетных мышцах было проведено у здоровых добровольцев, в нескольких случаях метод DWI также был использован при мы-шечных патологиях [176,177,[182][183][184] для изучения возможного применения полученных количественных параметров DWI в качестве биомаркеров.…”

Imagerie et spectroscopie par résonance magnétique nucléaire du muscle strié squelettique

“…La fiabilité des variables de diffusion mesurées dans le muscle squelettique a été améliorée par l'optimisation des paramètres de séquence de diffusion ainsi que des méthodes de traitement de données diffusion (Heemskerk et al 2010 ;Froeling et al 2010 ;Froeling et al 2013). Avec des schémas de séquence de diffusion dédiés, les variables calculées ont montré une corrélation satisfaisante avec la perfusion et la vascularisation du muscle squelettique (Karampinos et al 2010 ;Filli et al 2015). La plupart des études humaines sur la diffusion musculaire ont été menées sur des volontaires sains.…”