In vivo tibiofemoral cartilage strain mapping under static mechanical loading using continuous GRASP‐MRI

Abstract

Background Quantification of dynamic biomechanical strain in articular cartilage in vivo; in situ using noninvasive MRI techniques is desirable and may potentially be used to assess joint pathology. Purpose To demonstrate the use of static mechanical loading and continuous 3D‐MRI acquisition of the human knee joint in vivo to measure the strain in the tibiofemoral articular cartilage. Study Type Prospective. Subjects Five healthy human volunteers (four women, one man; age 25.6 ± 1.7) underwent MRI at rest, under static mechanical loading condition, and during recovery. Field Strength/Sequence A field strength of 3T was used. The sequence used was 3D‐continuous golden angle radial sparse parallel (GRASP) MRI and compressed sensing (CS) reconstruction. Assessment Tibiofemoral cartilage deformation maps under loading and during recovery were calculated using an optical flow algorithm. The corresponding Lagrangian strain was calculated in the articular cartilage. Statistical Tests Range of displacement and strain in each subject, and the resulting mean and standard deviation, were calculated. Results During the loading condition, the cartilage displacement in the direction of loading ranged from a minimum of –673.6 ± 121.9 μm to a maximum of 726.5 ± 169.5 μm. Corresponding strain ranged from a minimum of –7.0 ± 4.2% to a maximum of 5.4 ± 1.6%. During the recovery condition, the cartilage displacement in the same direction reduced to a minimum of –613.0 ± 129.5 μm and a maximum of 555.7 ± 311.4 μm. The corresponding strain range reduced to a minimum of –1.6 ± 7.5% to a maximum of 4.2 ± 2.6%. Data Conclusion This study shows the feasibility of using static mechanical loading with continuous GRASP‐MRI acquisition to measure the strain in the articular cartilage. By measuring strain during the loading and recovery phases, dynamic strain information in the articular cartilage might be able to be investigated. Level of Evidence: 2 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2020;51:426–434.

3D Muscle Deformation Mapping at Submaximal Isometric Contractions: Applications to Aging Muscle

“…MR imaging has been employed to map regional muscle or cartilage deformation based on sequences that map voxel displacement (displacement encoded imaging) or voxel velocity [Velocity encoded phase contrast imaging (VE-PC)] or MR tagging to track voxel displacements (Spatial Modulation of Magnetization, SPAMM) ( Chan et al, 2017 ; Malis et al, 2018 ; Sinha et al, 2018 ; Tan et al, 2018 ). In addition, deformation analysis of volumetric morphological images acquired in the relaxed and deformed states have been employed to study strain in the muscle ( Pamuk et al, 2016 ) and in the cartilage ( Menon et al, 2019 ). Velocity encoded MRI has been established as a method for strain and strain rate imaging of skeletal muscle ( Malis et al, 2018 ; Sinha et al, 2018 , 2020 ).…”

Updates on Compositional MRI Mapping of the Cartilage: Emerging Techniques and Applications

“…The MRF framework is highly flexible for multiparametric cartilage mapping but still poses a significant computational burden and scan time as the dimensionality FIGURE 11: (a) A photograph of the experimental setup used to asses cartilage strain maps under mechanical loading during MRI scan. 99 (b) Illustration of the process, consisting of an 18 minutes continuous acquisition using golden-angle radial acquisitions while the knee joint at rest, during mechanical loading, and during recovery. The image reconstruction is performed with compressed sensing methods, followed by motion correction using optical flow methods, and finally, Lagrangian strain is calculated to produce cartilage strain maps.…”

In-Situ Cartilage Functionality Assessment Based on Advanced MRI Techniques and Precise Compartmental Knee Joint Loading through Varus and Valgus Stress

“…Consequently, recent approaches have combined MRI techniques with simultaneous loading to assess the tissue's response to loading as an imaging surrogate parameter of its functionality. Recently, static mechanical loading has been combined with continuous 3D-MRI acquisition to measure the intra-tissue strain of articular cartilage [8], while earlier approaches aimed to determine displacement under applied loading by synchronizing loading with the MRI acquisition [9]. Principally, imaging of the knee joint under loading is possible in open low-field MRI scanners (i.e., B 0 ≤ 0.5 T) where the patient bears weight [10] or in closed-bore high-field (clinical) MRI scanners (i.e., B 0 ≥ 1.5 T) where the patient is loaded by prototypical devices.…”