Magnetic resonance imaging of the subthalamic nucleus for deep brain stimulation

Abstract

The subthalamic nucleus (STN) is one of the most important stereotactic targets in neurosurgery, and its accurate imaging is crucial. With improving MRI sequences there is impetus for direct targeting of the STN. High-quality, distortion-free images are paramount. Image reconstruction techniques appear to show the greatest promise in balancing the issue of geometrical distortion and STN edge detection. Existing spin echo- and susceptibility-based MRI sequences are compared with new image reconstruction methods. Quantitative susceptibility mapping is the most promising technique for stereotactic imaging of the STN.

Keywords: CNR = contrast-to-noise ratio; DBS = deep brain stimulation; DTI = diffusion tensor imaging; FA = fractional anisotropy; FGATIR = fast gray matter acquisition T1 IR; FLAIR = fluid attenuated IR; FLASH = fast low-angle shot; FSE = fast spin echo; GRE = gradient echo; IR = inversion recovery; NSA = number of signal averages; PSIR = phase-sensitive IR; QSM = quantitative susceptibility mapping; SE = spin echo; SN = substantia nigra; SNR = signal-to-noise ratio; STIR = short tau IR; STN = subthalamic nucleus; SWI = susceptibility-weighted imaging; SWPI = susceptibility-weighted phase imaging; T = tesla; T2*WI = T2-weighted magnitude imaging; T2WI = T2-weighted imaging; TI = inversion time; TR = relaxation time; ZI = zona incerta; deep brain stimulation; functional neurosurgery; magnetic resonance imaging; subthalamic nucleus.