title: Susceptibility-weighted imaging: current status and future directions.
abstract: Susceptibility-weighted imaging (SWI) is a method that uses the intrinsic nature of local magnetic fields to enhance image contrast in order to improve the visibility of various susceptibility sources and to facilitate diagnostic interpretation. It is also the precursor to the concept of the use of phase for quantitative susceptibility mapping (QSM). Nowadays, SWI has become a widely used clinical tool to image deoxyhemoglobin in veins, iron deposition in the brain, hemorrhages, microbleeds and calcification. In this article, we review the basics of SWI, including data acquisition, data reconstruction and post-processing. In particular, the source of cusp artifacts in phase images is investigated in detail and an improved multi-channel phase data combination algorithm is provided. In addition, we show a few clinical applications of SWI for the imaging of stroke, traumatic brain injury, carotid vessel wall, siderotic nodules in cirrhotic liver, prostate cancer, prostatic calcification, spinal cord injury and intervertebral disc degeneration. As the clinical applications of SWI continue to expand both in and outside the brain, the improvement of SWI in conjunction with QSM is an important future direction of this technology. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: The MRI Institute for Biomedical Research, Waterloo, ON, Canada.
authors.forename: Saifeng
authors.initials: S
authors.lastname: Liu
authors.affiliation: The MRI Institute for Biomedical Research, Waterloo, ON, Canada.
authors.forename: Sagar
authors.initials: S
authors.lastname: Buch
authors.affiliation: Department of Radiology, Wayne State University, Detroit, MI, USA.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Radiology, St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Hyun-Seok
authors.initials: HS
authors.lastname: Choi
authors.affiliation: The MRI Institute of Biomedical Research, Detroit, MI, USA.
authors.forename: Yongming
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Department of Radiology, Wayne State University, Detroit, MI, USA.
authors.forename: Charbel
authors.initials: C
authors.lastname: Habib
authors.affiliation: Department of Radiology, Wayne State University, Detroit, MI, USA.
authors.forename: Jiani
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Radiology, St. Mary's Hospital, The Catholic University of Korea, Seoul, South Korea.
authors.forename: Joon-Yong
authors.initials: JY
authors.lastname: Jung
authors.affiliation: Department of Radiology, Branch of Shanghai First Hospital, Shanghai, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Luo
authors.affiliation: The MRI Institute of Biomedical Research, Detroit, MI, USA.
authors.forename: David
authors.initials: D
authors.lastname: Utriainen
authors.affiliation: Department of Radiology, Henan Provincial People's Hospital, Zhengzhou, Henan, China.
authors.forename: Meiyun
authors.initials: M
authors.lastname: Wang
authors.affiliation: Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China.
authors.forename: Dongmei
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Radiology, Tianjin First Central Hospital, Tianjin, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Xia
authors.affiliation: The MRI Institute for Biomedical Research, Waterloo, ON, Canada.|Department of Radiology, Wayne State University, Detroit, MI, USA.|The MRI Institute of Biomedical Research, Detroit, MI, USA.|Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China.
authors.forename: E Mark
authors.initials: EM
authors.lastname: Haacke
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D001927:Brain Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods* / Q000639:trends; D005544:Forecasting; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods / Q000639:trends; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: cerebral microbleeds; multi-channel phase data combination; phase imaging; quantitative susceptibility mapping; stroke; susceptibility-weighted imaging