title: Quantitative Susceptibility Mapping: Contrast Mechanisms and Clinical Applications.
abstract: Quantitative susceptibility mapping (QSM) is a recently developed MRI technique for quantifying the spatial distribution of magnetic susceptibility within biological tissues. It first uses the frequency shift in the MRI signal to map the magnetic field profile within the tissue. The resulting field map is then used to determine the spatial distribution of the underlying magnetic susceptibility by solving an inverse problem. The solution is achieved by deconvolving the field map with a dipole field, under the assumption that the magnetic field is a result of the superposition of the dipole fields generated by all voxels and that each voxel has its unique magnetic susceptibility. QSM provides improved contrast to noise ratio for certain tissues and structures compared to its magnitude counterpart. More importantly, magnetic susceptibility is a direct reflection of the molecular composition and cellular architecture of the tissue. Consequently, by quantifying magnetic susceptibility, QSM is becoming a quantitative imaging approach for characterizing normal and pathological tissue properties. This article reviews the mechanism generating susceptibility contrast within tissues and some associated applications.
authors: Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, NC 27710; Department of Radiology, Duke University School of Medicine, Durham, NC 27710; Center for In Vivo Microscopy, Duke University School of Medicine, Durham, NC 27710.
authors: Chunlei
authors: C
authors: Liu
authors: Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, NC 27710.
authors: Hongjiang
authors: H
authors: Wei
authors: Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, NC 27710.
authors: Nan-Jie
authors: NJ
authors: Gong
authors: Brain Imaging and Analysis Center, Duke University School of Medicine, Durham, NC 27710.
authors: Matthew
authors: M
authors: Cronin
authors: Center for In Vivo Microscopy, Duke University School of Medicine, Durham, NC 27710.
authors: Russel
authors: R
authors: Dibb
authors: Center for In Vivo Microscopy, Duke University School of Medicine, Durham, NC 27710.
authors: Kyle
authors: K
authors: Decker
keywords: Alzheimer's disease; Parkinson's disease; brain; iron; multiple sclerosis; myelin; quantitative susceptibility mapping (QSM); susceptibility tensor imaging (STI)