title: Functional Neuroimaging: Fundamental Principles and Clinical Applications.
abstract: Functional imaging modalities, such as functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), are rapidly changing the scope and practice of neuroradiology. While these modalities have long been used in research, they are increasingly being used in clinical practice to enable reliable identification of eloquent cortex and white matter tracts in order to guide treatment planning and to serve as a diagnostic supplement when traditional imaging fails. An understanding of the scientific principles underlying fMRI and DTI is necessary in current radiological practice. fMRI relies on a compensatory hemodynamic response seen in cortical activation and the intrinsic discrepant magnetic properties of deoxy- and oxyhemoglobin. Neuronal activity can be indirectly visualized based on a hemodynamic response, termed neurovascular coupling. fMRI demonstrates utility in identifying areas of cortical activation (i.e., task-based activation) and in discerning areas of neuronal connectivity when used during the resting state, termed resting state fMRI. While fMRI is limited to visualization of gray matter, DTI permits visualization of white matter tracts through diffusion restriction along different axes. We will discuss the physical, statistical and physiological principles underlying these functional imaging modalities and explore new promising clinical applications.
authors.affiliation: Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine; Baltimore, MD, USA nkhanna1@umm.edu.
authors.forename: Nishanth
authors.initials: N
authors.lastname: Khanna
authors.affiliation: Section of Neuroradiology, University of Texas Health Science Center San Antonio; San Antonio, TX, USA.
authors.forename: Wilson
authors.initials: W
authors.lastname: Altmeyer
authors.affiliation: Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Medical Center; Baltimore MD, USA.
authors.forename: Jiachen
authors.initials: J
authors.lastname: Zhuo
authors.affiliation: Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland Medical Center; Baltimore MD, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Steven
mesh_terms: D001921:Brain / Q000503:physiopathology* / Q000601:surgery*; D001927:Brain Diseases / Q000503:physiopathology* / Q000601:surgery*; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000379:methods*
keywords: DTI; diffusion; fMRI; functional; tensor