title: Diffusion tensor imaging and tractography of the human language pathways: moving into the clinical realm.
abstract: The functional correlates of anatomical derangements are of interest to the neurological clinician. Diffusion tensor tractography (DTT) is a relatively new tool in the arsenal of functional neuroimaging, by which to assess white matter tracts in the brain. While much import has been given to tracking corticospinal tracts in neurological disease, studying language pathway interconnections using DTT has largely remained in the research realm. Hardware and software advances have allowed this tool to ease into clinical practice, with several radiologists, neurologists, and neurosurgeons now familiar with its applications. DTT images, although visually appealing, are founded in mathematical equations and assumptions, and require a more than basic understanding of principles and limitations before they can be integrated into routine clinical practice. Cognitive pathways like that of language, that are normally hard to assess and especially more so when pathologically affected, have been at the receiving end of several opposing and often controversial hypotheses, and the past decade has seen the clarification, validation or rejection of several of these by the in vivo charting of functional connectivity using DTT. The focus of this review is to illustrate DTT of the language pathways with emphasis on practical considerations, clinical applications, and limitations.
authors.affiliation: Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute of Medical Sciences and Technology, Trivandrum.
authors.forename: Prakash
authors.initials: P
authors.lastname: Muthusami
authors.forename: Jija
authors.initials: J
authors.lastname: James
authors.forename: Bejoy
authors.initials: B
authors.lastname: Thomas
authors.forename: T R
authors.initials: TR
authors.lastname: Kapilamoorthy
authors.forename: Chandrasekharan
authors.initials: C
authors.lastname: Kesavadas
mesh_terms: D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001925:Brain Damage, Chronic / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D001927:Brain Diseases / Q000473:pathology / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D056324:Diffusion Tensor Imaging / Q000379:methods*; D004292:Dominance, Cerebral / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D009412:Nerve Fibers / Q000473:pathology / Q000502:physiology; D009434:Neural Pathways / Q000503:physiopathology*; D009473:Neuronal Plasticity / Q000502:physiology; D011932:Reading; D013060:Speech / Q000502:physiology*; D013067:Speech Perception / Q000502:physiology*
keywords: arcuate fasciculus; diffusion tensor imaging; hemispheric dominance; language pathways; language plasticity; tractography