Personalised gait retraining for medial compartment knee osteoarthritis: a randomised controlled trial.

Background: Retraining individuals with medial compartment knee osteoarthritis to walk with a patient-specific change in their foot angle (ie, toe-in or toe-out angle) can reduce excessive joint loading related to disease progression. This study investigated the clinical, biomechanical, and structural efficacy of personalised foot progression angle modifications compared with sham treatment in patients with mild-to-moderate medial compartment knee osteoarthritis.

Methods: In this single-center, parallel-group, randomised controlled trial, we recruited individuals with symptomatic medial compartment knee osteoarthritis at the Human Performance Laboratory and Lucas Center for Imaging at Stanford University, CA, USA, using online and print media.

Exercise-Induced Changes in Knee Cartilage In Vivo: Comparing MRI Sequences.

The purpose was to assess the agreement in measures of acute knee cartilage thickness and composition change after loading in clinical knee osteoarthritis (OA) between two magnetic resonance imaging (MRI) acquisition approaches: (1) single sequence approach using quantitative double-echo in steady-state (qDESS), which allows simultaneous morphological and compositional scanning, versus (2) multi-sequence approach that captures morphology (fast spoiled gradient recalled (FSPGR) or qDESS) and composition (multi-echo spin echo (MESE)) separately. Twenty adults with clinical knee OA participated. 3T MR scans were acquired before and immediately after a 25-min treadmill walk at a standardized speed.

Improved Strength Prediction Combining MRI Biomarkers of Muscle Quantity and Quality.

Muscle strength declines with aging at a faster rate compared with muscle mass, suggesting that not only muscle quantity but also muscle quality and architecture are age-dependent. This study tested the hypothesis that quantitative MRI (qMRI)-derived biomarkers of muscle quality (fractional anisotropy [FA], radial diffusivity [RD], axial diffusivity [AD], fat fraction [FF], and T relaxation time) and architecture (fascicle length) could improve the prediction of skeletal muscle strength over muscle mass alone. We recruited 24 adults (12 female, age range 30-79 years).

Hamstring muscle architecture and microstructure changes following Nordic hamstring exercise training and detraining.

Background: While Nordic hamstring exercise (NHE) training has been shown to reduce hamstring strains, the muscle-specific adaptations to NHE across the 4 hamstrings remain unclear. This study investigates architectural and microstructural adaptations of the biceps femoris short head (BFsh), biceps femoris long head (BFlh), semitendinosus (ST), and semimembranosus (SM) in response to an NHE intervention.

Methods: Eleven subjects completed 9 weeks of supervised NHE training followed by 3 weeks of detraining.

T Clusters Are More Sensitive Than Mean T Change to Detect Early and Longitudinal Changes in Anterior Cruciate Ligament Reconstructed and Healthy Knees.

Background: Post-traumatic osteoarthritis (PTOA) often follows anterior cruciate ligament reconstruction (ACLR), leading to early cartilage degradation. Change in mean T fails to capture subject-specific spatial-temporal variations, highlighting the need for robust quantitative methods for early PTOA detection and monitoring.

Purpose/hypothesis: Develop and apply 3D T cluster analysis to ACLR and healthy knees over 2.

Improving Accuracy and Reproducibility of Cartilage T Mapping in the OAI Dataset Through Extended Phase Graph Modeling.

Background: The Osteoarthritis Initiative (OAI) collected extensive imaging data, including Multi-Echo Spin-Echo (MESE) sequences for measuring knee cartilage T relaxation times. Mono-exponential models are used in the OAI for T fitting, which neglects stimulated echoes and B inhomogeneities. Extended Phase Graph (EPG) modeling addresses these limitations but has not been applied to the OAI dataset.

Effects of dynamic [F]NaF PET scan duration on kinetic uptake parameters in the knee.

Introduction: Accurately estimating bone perfusion and metabolism using [F]NaF kinetics from shorter scan times could help address concerns related to patient comfort, motion, and throughput for PET scans. We examined the impact of changing the PET scan duration on the accuracy of [F]NaF kinetic parameters in the knee.

Methods: Both knees of twenty participants with and without osteoarthritis were scanned using a hybrid PET-MRI system (53 ± 13 years, BMI 25.

A deep learning approach for fast muscle water T2 mapping with subject specific fat T2 calibration from multi-spin-echo acquisitions.

This work presents a deep learning approach for rapid and accurate muscle water T with subject-specific fat T calibration using multi-spin-echo acquisitions. This method addresses the computational limitations of conventional bi-component Extended Phase Graph fitting methods (nonlinear-least-squares and dictionary-based) by leveraging fully connected neural networks for fast processing with minimal computational resources. We validated the approach through in vivo experiments using two different MRI vendors.

Advanced MRI Approaches for Evaluating Common Lower Extremity Injuries in Basketball Players: Current and Emerging Techniques.

Magnetic resonance imaging (MRI) can provide accurate and non-invasive diagnoses of lower extremity injuries in athletes. Sport-related injuries commonly occur in and around the knee and can affect the articular cartilage, patellar tendon, hamstring muscles, and bone. Sports medicine physicians utilize MRI to evaluate and diagnose injury, track recovery, estimate return to sport timelines, and assess the risk of recurrent injury.

Design and rationale of re-energize fontan: Randomized exercise intervention designed to maximize fitness in fontan patients.

In this manuscript, we describe the design and rationale of a randomized controlled trial in pediatric Fontan patients to test the hypothesis that a live-video-supervised exercise (aerobic+resistance) intervention will improve cardiac and physical capacity; muscle mass, strength, and function; and endothelial function. Survival of children with single ventricles beyond the neonatal period has increased dramatically with the staged Fontan palliation. Yet, long-term morbidity remains high.

Imaging of joint response to exercise with MRI and PET.

Imaging of the joint in response to loading stress may provide additional measures of joint structure and function beyond conventional, static imaging studies. Exercise such as running, stair climbing, and squatting allows evaluation of the joint response to larger loading forces than during weight bearing. Quantitative MRI (qMRI) may assess properties of cartilage and meniscus hydration and organization in vivo that have been investigated to assess the functional response of these tissues to physiological stress.

Latest advancements in imaging techniques in OA.

The osteoarthritis (OA) research community has been advocating a shift from radiography-based screening criteria and outcome measures in OA clinical trials to a magnetic resonance imaging (MRI)-based definition of eligibility and endpoint. For conventional morphological MRI, various semiquantitative evaluation tools are available. We have lately witnessed a remarkable technological advance in MRI techniques, including compositional/physiologic imaging and automated quantitative analyses of articular and periarticular structures.

PET Imaging in Osteoarthritis.

Osteoarthritis is a common cause of pain and morbidity resulting in heavy economic burden and large societal costs. Although cross-sectional imaging and in particular MR imaging have largely contributed to a better understanding of the complexity of this complex disease, especially in large joints such as the hip and knee joints, metabolic information of the subchondral bone and periarticular synovial environment has been consistently suggested to provide valuable supplemental information to morphologic and compositional MR imaging. The aim of this narrative review is to provide an overview of the role of the hybrid PET imaging in osteoarthritis with particular focus on PET/MR imaging.

A method for measuring B field inhomogeneity using quantitative double-echo in steady-state.

Purpose: To develop and validate a method for mapping for knee imaging using the quantitative Double-Echo in Steady-State (qDESS) exploiting the phase difference ( ) between the two echoes acquired. Contrary to a two-gradient-echo (2-GRE) method, depends only on the first echo time.

Methods: Bloch simulations were applied to investigate robustness to noise of the proposed methodology and all imaging studies were validated with phantoms and in vivo simultaneous bilateral knee acquisitions.

Gadolinium-free assessment of synovitis using diffusion tensor imaging.

The dynamic contrast-enhanced (DCE)-MRI parameter K can quantify the intensity of synovial inflammation (synovitis) in knees with osteoarthritis (OA), but requires the use of gadolinium-based contrast agent (GBCA). Diffusion tensor imaging (DTI) measures the diffusion of water molecules with parameters mean diffusivity (MD) and fractional anisotropy (FA), and has been proposed as a method to detect synovial inflammation without the use of GBCA. The purpose of this study is to (1) determine the ability of DTI to quantify the intensity of synovitis in OA by comparing MD and FA with our imaging gold standard K within the synovium and (2) compare DTI and DCE-MRI measures with the semi-quantitative grading of OA severity with the Kellgren-Lawrence (KL) and MRI Osteoarthritis Knee Score (MOAKS) systems, in order to assess the relationship between synovitis intensity and OA severity.

Characterization of Structural Bone Properties through Portable Single-Sided NMR Devices: State of the Art and Future Perspectives.

Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening.