Xeni Deligianni1,2, Michele Pansini3, Meritxell Garcia4, Anna Hirschmann4, Arno Schmidt-Trucksäss5, Oliver Bieri1,2, Francesco Santini1,2. 1. Department of Radiology, Division of Radiological Physics, University of Basel Hospital, Basel, Switzerland. 2. Department of Biomedical Engineering, University of Basel, Basel, Switzerland. 3. Department of Radiology, Kantonsspital Basel-Landschaft Bruderholz, Bruderholz, Switzerland. 4. Department of Radiology, University of Basel Hospital, Basel, Switzerland. 5. Department of Sports Medicine, University of Basel, Basel, Switzerland.
Abstract
PURPOSE: Assessing the functionality of muscle fibers is essential to monitor both pathological and physiological processes. Here, we present a new method for accurate, quantitative measurement of muscle contraction with magnetic resonance imaging (MRI) using an electrical muscle stimulator (EMS), hence allowing the direct assessment of muscle kinematics. METHODS: A commercially available EMS device was used to induce involuntary periodic muscle contraction of the vastus lateralis muscle (VL) synchronized with high-temporal-resolution cine phase contrast MRI acquisition at 3T. The proposed method was evaluated in ten male volunteers at varying levels of stimulation (10-18 mA) and maximum velocity, strain, and strain rate were calculated offline. RESULTS: Artifact-free velocity, strain and strain rate maps were produced and were consistent across the volunteers. Quantitatively, all parameters varied significantly at different levels of stimulation, in an approximately power-law dependence on the stimulation current. At 18 mA maximum contraction speeds at the beginning of the contraction were 4.28 ± 2.64 cm/s; principal strain was 0.30 ± 0.12; and positive in-plane strain rate was 0.25 ± 0.14 s-1 . CONCLUSION: MRI of EMS-controlled involuntary muscle contraction is feasible and allows offline calculation of velocity, strain and strain rate maps, which appear to depend significantly on the stimulation current used. Magn Reson Med 77:664-672, 2017.
PURPOSE: Assessing the functionality of muscle fibers is essential to monitor both pathological and physiological processes. Here, we present a new method for accurate, quantitative measurement of muscle contraction with magnetic resonance imaging (MRI) using an electrical muscle stimulator (EMS), hence allowing the direct assessment of muscle kinematics. METHODS: A commercially available EMS device was used to induce involuntary periodic muscle contraction of the vastus lateralis muscle (VL) synchronized with high-temporal-resolution cine phase contrast MRI acquisition at 3T. The proposed method was evaluated in ten male volunteers at varying levels of stimulation (10-18 mA) and maximum velocity, strain, and strain rate were calculated offline. RESULTS: Artifact-free velocity, strain and strain rate maps were produced and were consistent across the volunteers. Quantitatively, all parameters varied significantly at different levels of stimulation, in an approximately power-law dependence on the stimulation current. At 18 mA maximum contraction speeds at the beginning of the contraction were 4.28 ± 2.64 cm/s; principal strain was 0.30 ± 0.12; and positive in-plane strain rate was 0.25 ± 0.14 s-1 . CONCLUSION: MRI of EMS-controlled involuntary muscle contraction is feasible and allows offline calculation of velocity, strain and strain rate maps, which appear to depend significantly on the stimulation current used. Magn Reson Med 77:664-672, 2017.
Authors: Gustav J Strijkers; Ericky C A Araujo; Noura Azzabou; David Bendahan; Andrew Blamire; Jedrek Burakiewicz; Pierre G Carlier; Bruce Damon; Xeni Deligianni; Martijn Froeling; Arend Heerschap; Kieren G Hollingsworth; Melissa T Hooijmans; Dimitrios C Karampinos; George Loudos; Guillaume Madelin; Benjamin Marty; Armin M Nagel; Aart J Nederveen; Jules L Nelissen; Francesco Santini; Olivier Scheidegger; Fritz Schick; Christopher Sinclair; Ralph Sinkus; Paulo L de Sousa; Volker Straub; Glenn Walter; Hermien E Kan Journal: J Neuromuscul Dis Date: 2019