Mean magnetic susceptibility regularized susceptibility tensor imaging (MMSR-STI) for estimating orientations of white matter fibers in human brain

Xu Li, Peter C. M. van Zijl
2014 Magnetic Resonance in Medicine  
Purpose-There is an increasing number of studies showing that magnetic susceptibility in white matter fibers is anisotropic and may be described by a tensor. However, the limited head rotation possible for in vivo human studies leads to an ill-conditioned inverse problem in susceptibility tensor imaging (STI). Here we suggest combined use of limiting the susceptibility anisotropy to white matter and imposing morphology constraints on the mean magnetic susceptibility (MMS) for regularizing the
more » ... I inverse problem. Methods-The proposed MMS regularized STI (MMSR-STI) method was tested using computer simulations and in vivo human data collected at 3T. The fiber orientation estimated from both the STI and MMSR-STI method was compared to that from diffusion tensor imaging (DTI). Results-Computer simulations show that MMSR-STI method provides a more accurate estimation of the susceptibility tensor than the conventional STI approach. Similarly, in vivo data show that use of MMSR-STI method leads to a smaller difference between the fiber orientation estimated from STI and DTI for most selected white matter fibers. Conclusion-The proposed regularization strategy for STI can improve estimation of the susceptibility tensor in white matter.
doi:10.1002/mrm.25322 pmid:24974830 pmcid:PMC4134695 fatcat:zaxejiqwdzh6tjxnxvzgh6lmwe