title: The clinical utility of QSM: disease diagnosis, medical management, and surgical planning.
abstract: Quantitative susceptibility mapping (QSM) is an MR technique that depicts and quantifies magnetic susceptibility sources. Mapping iron, the dominant susceptibility source in the brain, has many important clinical applications. Herein, we review QSM applications in the diagnosis, medical management, and surgical treatment of disease. To assist in early disease diagnosis, QSM can identify elevated iron levels in the motor cortex of amyotrophic lateral sclerosis patients, in the substantia nigra of Parkinson's disease (PD) patients, in the globus pallidus, putamen, and caudate of Huntington's disease patients, and in the basal ganglia of Wilson's disease patients. Additionally, QSM can distinguish between hemorrhage and calcification, which could prove useful in tumor subclassification, and can measure microbleeds in traumatic brain injury patients. In guiding medical management, QSM can be used to monitor iron chelation therapy in PD patients, to monitor smoldering inflammation of multiple sclerosis (MS) lesions after the blood-brain barrier (BBB) seals, to monitor active inflammation of MS lesions before the BBB seals without using gadolinium, and to monitor hematoma volume in intracerebral hemorrhage. QSM can also guide neurosurgical treatment. Neurosurgeons require accurate depiction of the subthalamic nucleus, a tiny deep gray matter nucleus, prior to inserting deep brain stimulation electrodes into the brains of PD patients. QSM is arguably the best imaging tool for depiction of the subthalamic nucleus. Finally, we discuss future directions, including bone QSM, cardiac QSM, and using QSM to map cerebral metabolic rate of oxygen. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Eskreis-Winkler
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Jingwei
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Alexey
authors.initials: A
authors.lastname: Dimov
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Ajay
authors.initials: A
authors.lastname: Gupta
authors.affiliation: Department of Radiology, Weill Cornell Medicine, New York, NY, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D001927:Brain Diseases / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000601:surgery*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D057054:Molecular Imaging / Q000379:methods*; D011300:Preoperative Care / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*
chemical_list: D015415:Biomarkers
keywords: QSM; iron; neurodegenerative diseases; neurological; quantitative susceptibility mapping; susceptibility-weighted imaging