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The purpose of this study was to assess leg muscle quality and give a detailed description of leg muscle involvement in a series of Duchenne muscular dystrophy patients using quantitative MRI and strength measurements. Fatty infiltration, as well as total and contractile (not fatty infiltrated) cross sectional areas of various leg muscles were determined in(More)
The feasibility of a novel method for the noninvasive and local assessment of creatine (Cr) and phosphocreatine (PCr) dynamics in human skeletal muscle based on (13)C magnetic resonance (MR) spectroscopy is presented. A high dose of Cr, labeled at the guanidino C-4 position with (13)C 11% enrichment, was administered orally to a human subject for 5 days.(More)
The purpose of this work was to harmonize data acquisition and post-processing of single voxel proton MRS ((1) H-MRS) at 7 T, and to determine metabolite concentrations and the accuracy and reproducibility of metabolite levels in the adult human brain. This study was performed in compliance with local institutional human ethics committees. The same seven(More)
Force characteristics of skeletal muscle of knockout mice lacking creatine (Cr) due to a deletion of guanidinoacetate methyltransferase (GAMT) were studied in situ. Medial gastrocnemius muscles of anesthetized GAMT-deficient (GAMT-/-) and control (Con) littermates were stimulated at optimum length via the sciatic nerve at different stimulation frequencies(More)
The intrinsic nonuniformities in the transmit radiofrequency field from standard quadrature volume resonators at high field are particularly problematic for localized MRS in areas such as the temporal lobe, where a low signal-to-noise ratio and poor metabolite quantification result from destructive B₁⁺ field interference, in addition to line broadening and(More)
The purpose of this study was to implement a quantitative MR imaging method for the determination of muscular and fat content in individual skeletal muscles of patients with facioscapulohumeral muscular dystrophy (FSHD). Turbo Inversion Recovery Magnitude (TIRM) and multiecho MR images were acquired from seven FSHD patients and healthy volunteers. Signal(More)
Facioscapulohumeral muscular dystrophy (FSHD) is an untreatable disease, characterized by asymmetric progressive weakness of skeletal muscle with fatty infiltration. Although the main genetic defect has been uncovered, the downstream mechanisms causing FSHD are not understood. The objective of this study was to determine natural disease state and(More)
PURPOSE Microstructural and metabolic changes directly related to neuronal activation have been investigated using functional diffusion-weighted spectroscopy. METHODS The volume of interest was positioned in the primary visual cortex. A time series of alternating diffusion- and non-diffusion-weighted (1)H spectra was acquired at 7 T employing stimulated(More)
OBJECTIVE Becker muscular dystrophy (BMD) is characterised by broad clinical variability. Ongoing studies exploring dystrophin restoration in Duchenne muscular dystrophy ask for better understanding of the relation between dystrophin levels and disease severity. We studied this relation in BMD patients with varying mutations, including a large subset with(More)
Large variations of tip angle within a slice can lead to suboptimal pulse power optimization using standard techniques, which measure the average tip angle over a slice; this effect is especially pronounced at fields of 7 T and above. A technique was introduced that performed a volume-selective power optimization in less than 10 sec and automatically(More)