Lack of agreement between direct magnetic resonance imaging and statistical determination of a subthalamic target: the role of electrophysiological guidance

Abstract

The target that is directly identified by MR imaging is more remote (mainly in the lateral axis) from the site of the optimal functional response than targets obtained using other procedures, and the variability of this method in the lateral and superoinferior axes is greater. In contrast, the target defined by 3D MR imaging is closest to the target of optimal functional response and the variability of this method is the least great. Thus, 3D reconstruction adjusted to the AC-PC line is the most accurate technique for STN targeting, whereas direct visualization of the STN on MR images is the least effective. Electrophysiological guidance makes it possible to correct the inherent inaccuracy of the imaging and surgical techniques and is not designed to modify the initial targeting.

Imaging for deep brain stimulation: The zona incerta at 7 Tesla

“…Progress in medical imaging has improved the visualization of the DBS target structures. In the era of 1.5 T the direct visualization failed, secondary to insufficient contrast and low resolution [27,53] . At 3.0 T initial promis- ing results for the visualization of the ZI have been presented [54] .…”

Surgical targeting accuracy analysis of six methods for subthalamic nucleus deep brain stimulation

“…This procedure can be performed in 15 min including the time for the registration step. Nevertheless, although it is commonly used in many clinical institutions, employing T 2 -weighted MR images alone may result in less accurate target localization as we, as well as others [27,28] have shown. The other five targeting methods all require the use of non-rigid registration.…”

“…In addition, registered surgical targets from previous patients [24], as well as integration of multiple functional and anatomical references [25,26], may also be employed to facilitate STN DBS surgical targeting. Although the STN is often distinguishable on patient-specific T 2 -weighted MR images, which allow better visualization of this nucleus, the discrepancy between the target positions localized with T 2 -weighted MR images and those finalized using electrophysiological measurements should be taken into consideration, and the use of T 2 -weighted MR images alone should be employed cautiously [27,28]. Anatomical atlases, once linearly [29] or nonlinearly [14] mapped to individual pre-operative brain images, may provide information about subdivisions of deep-brain nuclei that are not directly visible on standard MR images.…”

Controversial Issues in Deep Brain Stimulation in Parkinson's Disease

“…While it is still used by some teams, there are concerns over its invasiveness and serious complications, such as CSF leakage and intracranial hemorrhage, which are major obstacles for most functional neurosurgeons [40]. The method involves injecting a contrast medium into the right frontal horn and acquiring representative images to determine the location of the anterior commissure and posterior commissure, which then can be used to calculate various target coordinates [41]. Compared with targeting methods that may have higher accuracy (e.g., ventriculography), targeting with MRI can be affected by the anterior displacement of the anterior commissure (AC), which elongates anterior commissure -posterior commissure (AC-PC) length [40].…”