Susceptibility Sensitive Magnetic Resonance Imaging Displays Pallidofugal and Striatonigral Fiber Tracts. Issue 4 (December 2016)

• Record Type: Journal Article
• Authors: Schneider, Till M.; Deistung, Andreas; Biedermann, Uta; Matthies, Cordula; Ernestus, Ralf-Ingo; Volkmann, Jens; Heiland, Sabine; Bendszus, Martin; Reichenbach, Jürgen R.
• Is Part Of: Operative neurosurgery. Volume 12:Issue 4(2016)
• Publication Date: 2016-12
• Subjects: Ansa lenticularis -- Deep brain stimulation -- Magnetic susceptibility -- Pallidofugal fibers -- Striatonigral fibers -- Subthalamic nucleus -- Quantitative susceptibility mapping; Nervous system -- Surgery -- Periodicals; 617.480590
• DOI: 10.1227/NEU.0000000000001256
• Languages: English
• ISSNs: 2332-4252

Abstract

Abstract : BACKGROUND: The pallidofugal and striatonigral fiber tracts form a functional part of the basal ganglionic neuronal networks. For deep brain stimulation, a surgical procedure applied in the treatment of Parkinson disease and dystonia, precise localization of pallidofugal pathways may be of particular clinical relevance for correct electrode positioning. OBJECTIVE: To investigate whether the pallidofugal and striatonigral pathways can be visualized with magnetic resonance imaging in vivo by exploiting their intrinsic magnetic susceptibility. METHODS: Three-dimensional gradient-echo imaging of 5 volunteers was performed on a 7 T magnetic resonance imaging system. To demonstrate that the displayed tubular structures in the vicinity of the subthalamic nucleus and substantia nigra truly represent fiber tracts rather than veins, gradient-echo data of a formalin-fixated brain and a volunteer during inhalation of ambient air and carbogen were collected at 3 T. Susceptibility weighted images, quantitative susceptibility maps, and effective transverse relaxation maps were reconstructed and the depiction of fiber tracts was qualitatively assessed. RESULTS: High-resolution susceptibility-based magnetic resonance imaging contrasts enabled visualization of pallidofugal and striatonigral fiber tracts noninvasively at 3 T and 7 T. We verified that the stripe-like pattern observed on susceptibility-sensitive images is not caused by veins crossing the internal capsule but by fiber tracts traversing the internal capsule. CONCLUSION: Pallidofugal and striatonigral fiber tracts have been visualized in vivo for the first time by using susceptibility-sensitive image contrasts. Considering the course of pallidofugal pathways, in particular for deep brain stimulation procedures in the vicinity of the subthalamic nucleus, could provide landmarks for optimal targeting during stereotactic planning. ABBREVIATIONS: 3D, 3-dimensional AC-PC, anterior commissure–posterior commissure AL, ansa lenticularis DBS, deep brain stimulation GPi, globus pallidus internus IC, internal capsule LF, lenticular fasciculus PD, Parkinson disease QSM, quantitative susceptibility maps R2*, relaxation rate STN, subthalamic nucleus STNF, subthalamic fasciculus SWI, susceptibility weighted images