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![(top row) Representative reconstructed water images of the right lower leg and (bottom row) 31 P spectra of the TP muscle of a DMD patient at (A) baseline, (B) 12-months and (C) 24-months. PDE/ATP ratios in TP muscles are shown in the graph and %fat for the all analyzed muscle for all three time points are as follows. Baseline: GCL = 5.6%; GCM = 7.3%; SOL = 7.1%; PER = 14,4%; TA = 6.24%; TP = 4.2%; 12-months: GCL = 6,6%; GCM = 8.8%; SOL = 5.2%; PER = 20.6%; TA = 5.71%; TP = 4.3%; 24-months: GCL = 10.1%; GCM = 11.3% SOL = 5.9%; PER = 24.7%; TA = 7.3%; TP = 4.3%. GCL = gastrocnemius lateral head, GCM = gastrocnemius medial head, SOL = soleus, PER = peroneus, TA = tibialis anterior, TP = tibialis posterior. Figure reproduced with permission from Hooijmans et al. [157].](publication/330759190/figure/fig3/AS:721125415870469@1548941105436/top-row-Representative-reconstructed-water-images-of-the-right-lower-leg-and-bottom.png)
(top row) Representative reconstructed water images of the right lower leg and (bottom row) 31 P spectra of the TP muscle of a DMD patient at (A) baseline, (B) 12-months and (C) 24-months. PDE/ATP ratios in TP muscles are shown in the graph and %fat for the all analyzed muscle for all three time points are as follows. Baseline: GCL = 5.6%; GCM = 7.3%; SOL = 7.1%; PER = 14,4%; TA = 6.24%; TP = 4.2%; 12-months: GCL = 6,6%; GCM = 8.8%; SOL = 5.2%; PER = 20.6%; TA = 5.71%; TP = 4.3%; 24-months: GCL = 10.1%; GCM = 11.3% SOL = 5.9%; PER = 24.7%; TA = 7.3%; TP = 4.3%. GCL = gastrocnemius lateral head, GCM = gastrocnemius medial head, SOL = soleus, PER = peroneus, TA = tibialis anterior, TP = tibialis posterior. Figure reproduced with permission from Hooijmans et al. [157].
Source publication
Neuromuscular diseases are characterized by progressive muscle degeneration and muscle weakness resulting in functional disabilities. While each of these diseases is individually rare, they are common as a group, and a large majority lacks effective treatment with fully market approved drugs. Magnetic resonance imaging and spectroscopy techniques (...
Context in source publication
Context 1
... stud- ies which followed 31 P MRS changes over time in NMD patients are scarce [9,152,157]. In the forearms of patients with DMD, it was shown that the ratio of the alkaline Pi signal over Pi and Pi/PCr were increased over one year in non-ambulant patients only [9,152]. In the legs of patients with DMD (an exam- ple is demonstrated in Fig. 3), no changes in 31 P MR indices were observed in a 2-year follow up, but in this study no distinction was made between ambulant and non-ambulant patients ...
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Citations
... MRI is frequently used as a tool to assess muscle atrophy and fat replacement in human subjects with muscle pathologies [36][37][38]. It has also been employed to study muscle involvement patterns during disease progression in OPMD [30,39]. ...
Background
Oculopharyngeal muscular dystrophy (OPMD) is an adult‐onset autosomal dominant myopathy. OPMD is caused by a short alanine expansion in the gene encoding for poly(A) binding protein nuclear 1 (PABPN1) forming insoluble nuclear aggregates. OPMD patients are predominantly heterozygous, and the knock‐in Pabpn1+/A17 mouse, which expresses one copy of the expanded Pabpn1 gene under the PABPN1 promoter genetically, mimics OPMD. Insights into the A17/+ mouse model are necessary to evaluate its preclinical value and test therapeutics for OPMD. Here, we performed a natural disease history study for the A17/+ model.
Methods
We combined muscle force measurements of the tibialis anterior with magnetic resonance imaging (MRI) measurements of the calf muscles made in 4‐, 8‐ and 12‐month‐old wild‐type and A17/+ mice. These measures were complemented by muscle histopathology staining and image quantification to detect PABPN1 aggregates and to assess muscle wasting. Statistical significance between genotypes over the three time points was assessed using ANOVA or Student's t test.
Results
PABPN1 nuclear aggregates were found in the 12‐month‐old A17/+ mice at similar quantities of ~2% across hindlimb muscles. We did not observe changes in muscle strength of the tibialis anterior in A17/+ mice. MRI analyses of hindlimb muscles revealed no metabolic difference, no fatty infiltration and limited muscle atrophy between A17/+ and +/+ mice. The plantaris muscle in A17/+ showed 30% atrophy at 12 months of age, which was corroborated by a 30% myofiber shift in the myosin heavy chain −2A to −2B ratio. Histopathologic staining did not reveal muscle wasting in the hindlimb muscles.
Conclusions
Despite the presence of PABPN1 insoluble aggregates in hindlimb muscles, muscle involvement in the 12‐month‐old A17/+ mice was limited. Our results query the usefulness of A17/+ hindlimb muscles for preclinical studies.
... Quantification of wT 2 can be achieved by fitting the Multi-Echo Spin Echo (MESE) images to a multi-exponential model on a pixel-by-pixel basis. This approach separated the contribution of fat protons from the water protons, providing information solely related to the relaxation of the water component in the tissue [15,16]. In addition, Weigel [17] proposed the Extended Phase Graph (EPG) theory as a powerful tool to effectively model the effect of gradients, radiofrequency (RF) pulses, relaxation, recovery and dephasing processes during the Magnetic Resonance Imaging (MRI) sequences. ...
... Additionally, while we considered FF measured from the MESE sequence as g.t. values [2,16], supervised training of the Myo-DINO network with 6-point Dixon FF maps could improve the accuracy of our methodology. Additionally, we did not compare the performance of our customized U-net architecture Table 3 Comparison between the reference FF, wT2 and B1 mean ROI-wise values and those reconstructed by Myo-DINO trained with Cycling Loss 2 with different λ cnn constraints, using the 17 echoes Multi-Echo Spin-Echo sequence as input volume. ...
... However, despite advancements, the precise quantification of fat remains challenging and an active field of research. [3][4][5] The multiple echoes necessary for water-fat imaging can be acquired through spin echo or gradient echo imaging using multiple acquisitions or a single acquisition with multiple echoes. 6,7 Research indicates that increasing the number of echoes significantly benefits signal-to-noise ratio (SNR) and reconstruction quality. ...
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... Paediatric neuromuscular diseases (NMDs) include a variety of rare disorders that are characterized by progressive muscle degeneration and muscle weakness, which lead to functional disabilities (1,2). There are approximately 600 different NMDs affecting 1 in 3,000 individuals around the world (3). ...
Introduction
Parents of children with neuromuscular diseases experience multiple difficulties in their daily lives that affect their physical and psychological health. The risk factors for these health issues have not been sufficiently investigated. Therefore, the aim of this study was to analyze the potential predictors of overload in these parents, including QoL, somatic symptomatology, life satisfaction, psychological adjustment and certain sociodemographic variables.
Methods
A cross-sectional research study was conducted among parents who are caregivers for children with NMD in Spain. A convenience sample of 110 parents who were contacted by associations and hospitals was used. Variables were evaluated using the sociodemographic questionnaire, CarerQol-7D, PHQ-15, Barthel Index, Psychological Adaptation Scale, Zarit Overload Scale and Satisfaction with Life Scale.
Results
One of the most relevant findings of the present study is the identification of 3 overload groups (mild to moderate, moderate to severe, and severe overload) based on life satisfaction and somatic symptom scores within the predictive model of the discriminate analysis. Wilk’s lambda of the discriminant function was 0.568, χ² (2, n = 55) = 8.815, p < 0.001.
Discussion
This study presents a model that reveals the influence of unemployment, having a child with a severe level of dependency, the presence of somatic symptomatology and life satisfaction on caregiver overload. Likewise, the caregiver’s self-esteem could be a protective factor against overload.
... Magnetic resonance elastography (MRE) is based on the imaging of shear waves and enables quantitative evaluation of biomechanical tissue properties of skeletal muscle. MRE-derived biomechanical properties during skeletal muscle contraction and relaxation can reflect skeletal muscle function [94]. Recent studies demonstrated that MRE was a reliable technique to quantitatively detect muscle stiffness on thigh muscles and paraspinal muscles [95,96]. ...
Sarcopenia is a syndrome described as a progressive and generalized loss of muscle mass and strength, with decrease in physical performance. It is related to an increased risk of many adverse events, such as falls, fractures, osteoporosis, major postoperative complications, loss of quality of life, prolonged hospital stay, disability, and even death. Although sarcopenia can also be assessed using a handheld dynamometer and a short physical performance battery (SPPB); it has lower accuracy, sensitivity, and specificity. Previous studies confirmed that imaging methods can serve as an important tool in the assessment of muscle mass and quality, and can even detect microscopic changes in muscle, achieving an early diagnosis of sarcopenia. Therefore, this article reviews the advantages and disadvantages of clinical and imaging assessment methods, specific applications, and the development of imaging techniques for the assessment of sarcopenia, including the currently unresolved problems.
... For example, magnetic resonance imaging (MRI) provides detailed images of muscle tissue anatomy, and can provide quantitative estimates of muscle metabolites, edema and fat replacement not visible using neurophysiological techniques, and with excellent spatial resolution. 9,10 The fundamental limitation of current muscle MRI is that although it provides detailed information on muscle structure, images are static and provide no indication of muscle function. Clinically, this poses a particular challenge because muscle fat replacement usually occurs as the disease's end-stage, representing permanent contractile muscle tissue loss. ...
Magnetic resonance imaging (MRI) is routinely used in the musculoskeletal system to measure skeletal muscle structure and pathology in health and disease. Recently, it has been shown that MRI also has promise for detecting the functional changes, which occur in muscles, commonly associated with a range of neuromuscular disorders. This review focuses on novel adaptations of MRI, which can detect the activity of the functional sub‐units of skeletal muscle, the motor units, referred to as “motor unit MRI (MUMRI).” MUMRI utilizes pulsed gradient spin echo, pulsed gradient stimulated echo and phase contrast MRI sequences and has, so far, been used to investigate spontaneous motor unit activity (fasciculation) and used in combination with electrical nerve stimulation to study motor unit morphology and muscle twitch dynamics. Through detection of disease driven changes in motor unit activity, MUMRI shows promise as a tool to aid in both earlier diagnosis of neuromuscular disorders and to help in furthering our understanding of the underlying mechanisms, which proceed gross structural and anatomical changes within diseased muscle. Here, we summarize evidence for the use of MUMRI in neuromuscular disorders and discuss what future research is required to translate MUMRI toward clinical practice.
Level of Evidence
5
Technical Efficacy
Stage 3
... with muscle injury are disruption of the architecture and microstructure, inflammation, fibrosis, and sometimes the replacement of muscle tissue by fat. 2 Training interventions aim to improve muscle function through for example compositional adaptations including hypertrophy of the muscle cells and changes in fiber length and pennation angle. In recent years, Quantitative Magnetic Resonance Imaging (qMRI) emerged as an invaluable tool and enabled researchers and healthcare professionals to noninvasively assess the composition and overall health of skeletal muscle, providing crucial insights into various health conditions, such as muscle wasting diseases, sports injuries, and age-related muscle decline. ...
... 21 In patients with neuromuscular diseases (NMD), progressive replacement of muscle fibers by adipose tissue occurs during disease progression. 2 The patterns of muscles affected by fat infiltration are quite characteristic of the respective (Fig. 2a-c). In NMD, PDFF allowed the detection of marginal longitudinal changes in muscle fat content and has been shown to be superior to qualitative MRI and functional tests. ...
... 12 Because fat content is highly correlated with muscle strength and function tests in NMD, it is likely to play a central role in determining endpoints for future therapeutic trials. 2 In metabolic diseases, higher body mass index (BMI) was associated with increasing muscular PDFF values, possibly indicating pathological ectopic fat deposition. In patients with type 2 diabetes mellitus, high HbA1c levels were associated with significantly higher muscle PDFF. ...
Due to its exceptional sensitivity to soft tissues, MRI has been extensively utilized to assess anatomical muscle parameters such as muscle volume and cross‐sectional area. Quantitative Magnetic Resonance Imaging (qMRI) adds to the capabilities of MRI, by providing information on muscle composition such as fat content, water content, microstructure, hypertrophy, atrophy, as well as muscle architecture. In addition to compositional changes, qMRI can also be used to assess function for example by measuring muscle quality or through characterization of muscle deformation during passive lengthening/shortening and active contractions. The overall aim of this review is to provide an updated overview of qMRI techniques that can quantitatively evaluate muscle structure and composition, provide insights into the underlying biological basis of the qMRI signal, and illustrate how qMRI biomarkers of muscle health relate to function in healthy and diseased/injured muscles. While some applications still require systematic clinical validation, qMRI is now established as a comprehensive technique, that can be used to characterize a wide variety of structural and compositional changes in healthy and diseased skeletal muscle. Taken together, multiparametric muscle MRI holds great potential in the diagnosis and monitoring of muscle conditions in research and clinical applications.
Evidence Level
5
Technical Efficacy
Stage 2
... 1 Among those, intramuscular fat fraction (FF) is a marker of disease severity and water T1 (T1 H 2 0 ) is an MRI biomarker sensitive to active muscle damage including edema, inflammation or myocyte necrosis. 2,3 Recently, MR fingerprinting (MRF) has been proposed for fast and simultaneous quantification of FF, T1 H 2 0 , T2 H 2 0 , and/or fat T1 (T1 fat ) in different anatomical targets, [4][5][6][7][8] including skeletal muscle. [9][10][11][12][13] Various approaches were proposed to isolate the water and lipid components of the MR fingerprints. ...
... (w, f) is calculated by nulling the derivative of J with regard to . We obtain: J = 2(̂(w, f)||d|| 2 ...
Purpose
To propose an efficient bi‐component MR fingerprinting (MRF) fitting method using a Variable Projection (VARPRO) strategy, applied to the quantification of fat fraction (FF) and water T1 (T1H20) in skeletal muscle tissues.
Methods
The MRF signals were analyzed in a two‐step process by comparing them to the elements of separate water and fat dictionaries (bi‐component dictionary matching). First, each pair of water and fat dictionary elements was fitted to the acquired signal to determine an optimal FF that was used to merge the fingerprints in a combined water/fat dictionary. Second, standard dictionary matching was applied to the combined dictionary for determining the remaining parameters. A clustering method was implemented to further accelerate the fitting. Accuracy, precision, and matching time of this approach were evaluated on both numerical and in vivo datasets, and compared to the reference dictionary‐matching approach that includes FF as a dictionary parameter.
Results
In numerical phantoms, all MRF parameters showed high correlation with ground truth for the reference and the bi‐component method (R² > 0.98). In vivo, the estimated parameters from the proposed method were highly correlated with those from the reference approach (R² > 0.997). The bi‐component method achieved an acceleration factor of up to 360 compared to the reference dictionary matching.
Conclusion
The proposed bi‐component fitting approach enables a significant acceleration of the reconstruction of MRF parameter maps for fat‐water imaging, while maintaining comparable precision and accuracy to the reference on FF and T1H20 estimation.
... It provides a direct assessment of muscle and nerve function, identifies the location of the neuromuscular system's dysfunction, and is sensitive to minor abnormalities in muscle and nerve function. In addition, Therefore, EMG is often preferred over MRI for the diagnosis of NMDs [3]. ...
... Diffusion tensor imaging (DTI) has proved its superiority in the demonstration of alterations in the muscle microstructures which occur in various diseases [11][12][13]. Fractional anisotropy (FA) and mean diffusivity (MD) are the main diagnostic DTI parameters used in detecting changes in isotropic/anisotropic water molecule diffusion which occur in different pathologies [14,15]. However, these changes are not disease-specific limiting DTI role so far [16,17]. ...
... Muscle performance capacity has shown considerable dependance on microstructural variations which can result in decreased power of contraction and increased muscle rigidity. Such matrix changes have been noticed with increased volume of the extra-cellular matrix (e.g., fibrosis) [2,10,12,24]. ...
Background
Low back pain (LBP) is one of the most common musculoskeletal complaints and considered as the most disabling condition among general population. Magnetic resonance imaging (MRI) is the preferred modality in imaging of LBP. Diffusion tensor imaging (DTI) is a version of MRI that can detect tissue microstructure changes occurring in different pathologies. The commonly used parameters are fractional anisotropy (FA) and mean diffusivity (MD). We aimed in this study to evaluate the role of DTI in the assessment of back muscles in young adults with chronic LBP with no major neurological or orthopedic disorders.
Results
There was a statistically significant difference in MD values of back muscles between patients and control groups. At the ROC curve, for psoas muscle, the AUC was 0.906 with a cutoff point of 0.951. Sensitivity and specificity were 89.2% and 90.9% with accuracy 89.8%. For multifidus muscle, the AUC was 0.919 with a cutoff point of 1.29. Sensitivity and specificity were 91.9% and 90.9% with accuracy 91.4%. For erector spinae muscle, the AUC was 0.834 with a cutoff point of 1.224. Sensitivity and specificity were 81.1% and 72.7% with accuracy 77.9%. There was a statistically significant difference in FA values of back muscles between the patients and control groups. At the ROC curve, for psoas muscle, the AUC was 0.840 with a cutoff point of 0.546. Sensitivity and specificity were 81.1% and 72.7% with accuracy 77.97%. For multifidus muscle, the AUC was 0.875 with a cutoff point of 0.415. Sensitivity and specificity were 81.1% and 90.9% with accuracy 84.7%. For erector spinae muscle, the AUC was 0.805 with a cutoff point of 0.437. Sensitivity and specificity were 81.1% and 77.3% with accuracy 79.7%.
Conclusions
DTI is a valuable promising noninvasive tool in the assessment of back muscles quality in patient with chronic low back pain, with no detected neurological or orthopedic pathologies. This is due to its sensitivity to microscopic intracellular changes that could not be detected on conventional imaging, allowing better tissue characterization.
