Search results for "MR"

Myostatin/activin blocking combined with exercise reconditions skeletal muscle expression profile of mdx mice

2015

Duchenne Muscular Dystrophy is characterized by muscle wasting and decreased aerobic metabolism. Exercise and blocking of myostatin/activin signaling may independently or combined counteract muscle wasting and dystrophies. The effects of myostatin/activin blocking using soluble activin receptor-Fc (sActRIIB-Fc) administration and wheel running were tested alone or in combination for seven weeks in dystrophic mdx mice. Expression microarray analysis revealed decreased aerobic metabolism in the gastrocnemius muscle of mdx mice compared to healthy mice. This was not due to reduced home-cage physical activity, and was further downregulated upon sActRIIB-Fc treatment in enlarged muscles. However…

Hoffa’s fat pad thickness: a measurement method with sagittal MRI sequences

2021

Abstract Background Hoffa’s fat pad is a structure located within the fibrous joint capsule of the knee joint, but outside the synovial cavity. It plays an important biomechanical and metabolic role in knee joint, reducing the impact of forces generated by loading and producing cytokines. Changes in its size can induce modifications in the knee homeostasis. However, a great variability exists regarding its measurements. This work aims to evaluate the reliability of a measurement method of Hoffa’s fat pad dimensions through MRI. Methods 3T sagittal IW 2D TSE fat-suppressed MRI sequences, taken from the OAI (Osteoarthritis initiative) database, of 191 male and female patients, aged between 40…

Stellenwert der MR-Tomographie bei traumatischen Patellaluxationen

1995

PURPOSE To describe the MR imaging findings in patients with lateral patellar dislocation. MATERIAL AND METHODS The MRIs of 31 patients with patellar dislocation were evaluated retrospectively. Arthroscopic surgery was performed in 23 cases. RESULTS Hemarthrosis was found in 30/31, contusions of the lateral femoral condyle in 30/31 and of the medial patellar facet in 26/31 cases. Injury of the medial patellar retinaculum was seen in 28/31 cases. Osteochondral fractures were found in 18 patients; compared to arthroscopy there were one false-positive and 5 false-negative findings concerning loose cartilage bodies. In 7 cases, patellar dislocation was not suspected before MR imaging. CONCLUSIO…

Bone and cartilage characteristics in postmenopausal women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis

2015

Objectives: To evaluate the association between radiographically-assessed knee osteoarthritis and femoral neck bone characteristics in women with mild knee radiographic osteoarthritis and those without radiographic osteoarthritis. Methods: Ninety postmenopausal women (mean age [SD], 58 [4] years; height, 163 [6] cm; weight, 71 [11] kg) participated in this cross-sectional study. The severity of radiographic knee osteoarthritis was defined using Kellgren-Lawrence grades 0=normal (n=12), 1=doubtful (n=25) or 2=minimal (n=53). Femoral neck bone mineral content (BMC), section modulus (Z), and cross-sectional area (CSA) were measured with DXA. The biochemical composition of ipsilateral knee cart…

2020

(1) Background: Assessments of intervertebral disc (IVD) changes, and IVD tissue adaptations due to physical activity, for example, remains challenging. Newer magnetic resonance imaging techniques can quantify detailed features of the IVD, where T2-mapping and T2-weighted (T2w) and Dixon imaging are potential candidates. Yet, their relative utility has not been examined. The performances of these techniques were investigated to characterize IVD differences in asymptomatic individuals with distinct physical activity histories. (2) Methods: In total, 101 participants (54 women) aged 25–35 years with distinct physical activity histories but without histories of spinal disease were included. T1…

MRI findings and physical performance as predictors of flight-induced musculoskeletal pain incidence among fighter pilots

2017

Summary Study aim: The aim of this study was to evaluate the possible association of pre-career magnetic resonance imaging (MRI) find­ings and physical performance level with possible musculoskeletal disorders during jet flight training. Material and methods: The study group consisted of 73 fighter pilots who had undergone pre-career cervical and lumbar spine MRI. Physical performance of a subgroup of the pilots (n = 67) was measured initially at the same time and followed up to the fast jet training phase (ranging from 3.8 to 7.0 years). Musculoskeletal pain history during pilot training was taken from the medical charts. MRI findings and physical performance were associated with perceived…

MRI evaluation to predict tendon size for knee ligament reconstruction.

2017

Background The aim of this study is to evaluate a possible correlation between specific anthropometric parameters and sizes of knee tendons commonly used for ACL reconstruction. We hypothesized that specific clinical and radiological knee measurements could be better tendon sizes predictors than age, gender, height and weight. Materials and methods 100 consecutive patients were enrolled and 77 patients met the inclusion criteria of the study. All patients underwent a MRI of the knee with a 1.5 T super conducting MR System. For each patient, anthropometric data such as gender, height, weight, body mass index (BMI) and knee circumference were recorded. Specific MRI knee measurements were perf…

MUSCLE BIOENERGETIC ABNORMALITY IN MYOTONIC-DYSTROPHY - A SECONDARY MITOCHONDRIAL DISORDER

1993

International audience; Abstract: The thenar muscles and gastrocnemius of a patient with myotonic dystrophy were investigated, at rest, by phosphorus nuclear magnetic resonance spectroscopy. A decrease in phosphocreatine level and an increase in inorganic phosphate and phosphodiester levels were found in the gastrocnemius, which was clinically spared, whilst the thenar muscles, which were wasted and affected by myotonia, exhibited only an increased inorganic phosphate level and an elevated pH. These findings were comparable with those found in other muscular disorders, such as Duchenne's and Becker's dystrophies, as well as in limb girdle dystrophy. They suggested that the abnormalities obs…

On application of kernel PCA for generating stimulus features for fMRI during continuous music listening

2018

Background There has been growing interest towards naturalistic neuroimaging experiments, which deepen our understanding of how human brain processes and integrates incoming streams of multifaceted sensory information, as commonly occurs in real world. Music is a good example of such complex continuous phenomenon. In a few recent fMRI studies examining neural correlates of music in continuous listening settings, multiple perceptual attributes of music stimulus were represented by a set of high-level features, produced as the linear combination of the acoustic descriptors computationally extracted from the stimulus audio. New method fMRI data from naturalistic music listening experiment were…

Connectivity Patterns During Music Listening: Evidence for Action-Based Processing in Musicians

2017

Musical expertise is visible both in the morphology and functionality of the brain. Recent research indicates that functional integration between multi-sensory, somato-motor, default-mode (DMN), and salience (SN) networks of the brain differentiates musicians from non-musicians during resting state. Here, we aimed at determining whether brain networks differentially exchange information in musicians as opposed to non-musicians during naturalistic music listening. Whole-brain graph-theory analyses were performed on participants' fMRI responses. Group-level differences revealed that musicians' primary hubs comprised cerebral and cerebellar sensorimotor regions whereas non-musicians' dominant …