Duchenne and Becker muscular dystrophy (DMD and BMD, respectively) are characterized by progressive loss of muscle function combined with an increase in fat tissue in muscle. In some muscles this... Show moreDuchenne and Becker muscular dystrophy (DMD and BMD, respectively) are characterized by progressive loss of muscle function combined with an increase in fat tissue in muscle. In some muscles this process of ‘fat replacement’ starts earlier or progresses faster than in others and this occurs in a consistent temporal pattern. In addition, even within muscles fat replacement seems to progress heterogeneously. Evidently there are factors that vary between and within muscles which cause differential fat replacement of muscle tissue, but these are currently unknown. The identification of factors that influence this process of muscle degeneration could support the selection of current, and the development of future, therapies.The aim of part 1 of this thesis was to identify differences between muscles that are related to muscle fat replacement over time. These can provide therapeutical targets for, and support the design of, future clinical trials in DMD and BMD. Part 2 aimed to develop new approaches to study intramuscular differences in muscle physiology and mechanics in healthy muscle. These can be applied in neuromuscular disease in the future, and can be related to intramuscular differences in disease progression. Show less
In this thesis, multiple approaches have been investigated for the simultaneous acquisition of 4D angiography and perfusion images using arterial spin labeling (ASL) MRI. Time-encoded pseudo... Show moreIn this thesis, multiple approaches have been investigated for the simultaneous acquisition of 4D angiography and perfusion images using arterial spin labeling (ASL) MRI. Time-encoded pseudo-continuous (ASL) preparation was combined with multiple different readout modules, such as Look-Locker, Simultaneous multi-slice acquisition or a golden angle based non-Cartesian k-space trajectory to obtain high temporal resolution multi-time point data. These datasets were then used to improve the quantification of ASL signal and to obtain cerebral blood flow, arterial transit time and arterial blood volume maps. These quantitative maps hold the potential to provide important information in for example patients with stroke or Alzheimer’s disease. In addition, one of the assumptions within the two-component kinetic model to obtain these quantitative maps was investigated to study the separation of the macrovascular and perfusion component of the ASL signal. Show less
