High resolution myelin water imaging in rat spinal cord in vivo with actively decoupled implanted RF coil

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 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. Quantitative T2 measurements used in myelin water imaging require very high SNR and homogeneity of the B1 field, making it challenging to apply this technique in rat spinal cord in vivo. Although the use of a small surface coil implanted surgically next to the cord significantly improves SNR [4], the B1 field inhomogeneity remains a problem. We have designed and built an RF implanted coil, which is actively decoupled from a volume coil. Here we present preliminary results of high spatial resolution myelin water imaging using this system.