Fig 1.
Representative axial T2-weighted (a) and MDEFT (b) sequence of a patient undergoing DBS implantation of the GPi.
Note the good demarcation of the subnuclei of the basal ganglia on the MDEFT image.
Table 1.
Demographics and lead characteristics in patients with GPi DBS.
Fig 2.
Determination of the AP-, ML- and VD-Index of the active contact C.
A: A line between the most anterior (A) and posterior (P) points of the GPi constitutes the AP-line. Another line through the active contact C and perpendicular to AP intersects the AP-line in S. The AP-Index can be calculated as AP-Index = AS/AP. B: The medial (M) and lateral (L) point of the GPi are located on a line perpendicular to the AP-line crossing the active contact C. The ML-Index can be calculated as ML-Index = MC/ML. C: The ventral (V) and dorsal (D) point of the GPi are located on a line perpendicular to the ML-line crossing the active contact C. The VD-Index can be calculated as VD-Index = VC/VD. D: An overlay of the postoperative CT-scan at the level of the active contact and the MDEFT MRI sequence shows the border of the GPi after segmentation reveals the position of the active contact in relation to the anatomical borders of the GPi.
Fig 3.
Representative MDEFT sequences of different patients undergoing DBS implantation of the GPi.
(GPi, globus pallidus internus; GPe, globus pallidus externus; Put, Putamen)
Table 2.
Comparison of target coordinates relative to MCP for DBS leads of indirect atlas-based and direct MDEFT-based planning.
Table 3.
Comparison of the average of the differences (Δ) of LAT-, AP- and VERT-coordinates between the selected target defined by direct MDEFT-based and indirect atlas-based planning.
Table 4.
Comparison of target coordinates relative to MCP for DBS leads of direct MDEFT-based planning between Parkinson and dystonia patients.
Fig 4.
Reconstruction of the implanted DBS leads and 3D-scatterplot of the actice contact position.
A: Reconstruction of DBS leads of a patient with bilateral DBS demonstrates lead location in the posterior part of the GPi. B: 3D-scatterplot of the actice contact position (red dots) relative to the border of the GPi. Position of the vast majority of the active contacts is in the posterior (AP-Index > 0.5) and ventral (VD-Index < 0.5) part of the GPi.
Table 5.
Comparison of the coordinates of the tip of the DBS lead relative to MCP in PD and dystonia patients with MDEFT-based planning.
Table 6.
Parameters of different T1 weighted sequences used for targeting the GPi in DBS surgery.