High resolution 3D myelin water imaging in excised rat spinal cord

Introduction Myelin water imaging has been successfully used to assess myelin content in human and animal CNS tissue [1,2]. It has been shown that fractional amounts of water trapped between myelin sheaths – the so called myelin water fraction (MWF) [3] correlates well with the amount of myelin in a rat model of spinal cord injury (SCI) [2] and can therefore be an important marker of the cord pathology. One of the limitations of the current CPMG based myelin water imaging technique is that it is a single slice technique. It has been shown that a 3D version of this technique can be achieved by applying a second phase encoding gradient to provide localization along the slice direction [4]. In this pilot study we applied the 3D CPMG sequence to acquire very high spatial resolution 3D MWF maps from excised rat spinal cord. The 3D technique produced high quality data that compared favourably with the 2D measurements.