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.
Arjun S. Chandran, Michael Bynevelt and Christopher R. P. Lind
Alex J. Koefman, Melissa Licari, Michael Bynevelt and Christopher R. P. Lind
An objective biomarker for pain is yet to be established. Functional MRI (fMRI) is a promising neuroimaging technique that may reveal an objective radiological biomarker. The purpose of this study was to evaluate fMRI technology in the setting of lumbosacral radiculopathy and discuss its application in revealing a biomarker for pain in the future.
A prospective, within-participant control study was conducted. Twenty participants with painful lumbosacral radiculopathy from intervertebral disc pathology were recruited. Functional imaging of the brain was performed during a randomly generated series of nonprovocative and provocative straight leg raise maneuvers.
With a statistical threshold set at p < 0.000001, 3 areas showed significant blood oxygen level–dependent (BOLD) signal change: right superior frontal gyrus (x = 2, y = 13, z = 48, k = 29, Brodmann area 6 [BA6]), left supramarginal cortex (x = −37, y = −44, z = 33, k = 1084, BA40), and left parietal cortex (x = −19, y = −41, z = 63, k = 354, BA5). With a statistical threshold set at p < 0.0002, 2 structures showed significant BOLD signal change: right putamen (x = 29, y = −11, z = 6, k = 72) and bilateral thalami (right: x = 23, y = −11, z = 21, k = 29; x = 8, y = −11, z = 9, k = 274; and left: x = −28, y = −32, z = 6, k = 21).
The results in this study compare with those in previous studies and suggest that fMRI technology can provide an objective assessment of the pain experience.