Catheter-based polarimetric imaging to complement MRI for deep brain stimulation neurosurgery

Abstract

Significance: Deep brain stimulation (DBS) is an established treatment for movement disorders and other neurological conditions. Accurate localization of small deep brain nuclei, such as the subthalamic nucleus (STN) and internal pallidum (GPi), is crucial for successful DBS outcomes. However, magnetic resonance imaging (MRI), commonly used for DBS planning, lacks the resolution and contrast needed to directly delineate these target structures.

Aim: We aim to explore the potential of catheter-based polarization-sensitive optical coherence tomography (PS-OCT) as a complementary imaging tool for high-resolution visualization of tissue surrounding the DBS insertion trajectory.

Approach: We simulated DBS implantation surgery at three targets in a post-mortem nonhuman primate head. PS-OCT, using advanced reconstruction algorithms for absolute depth-resolved birefringence, was compared with MRI for its ability to visualize and differentiate structural details.

Results: PS-OCT provided more detailed and accurate structural information than MRI while maintaining consistency with MRI results. Its compact form factor and imaging paradigm integrate seamlessly into the surgical workflow, offering new insights for intraoperative decision-making.

Conclusions: PS-OCT functions as an intraoperative imaging tool, offering valuable guidance during the procedure. These findings establish PS-OCT as a promising complementary tool for DBS, with potential for further clinical validation and in vivo studies.

Keywords: Parkinson’s disease; birefringence; nonhuman primates; polarization-sensitive optical coherence tomography; white matter fiber tract.

Fig. 1

Overview of the skull removal and registration process, aligning the post-op MRI to the pre-op MRI to determine the imaging trajectory coordinates in the pre-op MRI scan, followed by the registration of the SCMAC-MRI63 template to the pre-op MRI from the CERVO-MRI dataset.

Fig. 2

Co-registration of PS-OCT and MRI data. (a) The imaged track is displayed in a CERVO-MRI T1w scan, visualized in three dimensions. (b) The extraction of the imaged volume from the T1w CERVO-MRI scan is shown, along with the corresponding volume from the SCMAC-MRI63 template. (c) A stereotactic frame with an attached PS-OCT catheter is depicted, illustrating its positioning during imaging, along with a magnified view of the catheter tip. (d) The PS-OCT image formation process is illustrated, showing the acquisition of a single A-line, the formation of rotations and one pullback, as well as the unfolded en face PS-OCT image (carpet view) with OA colormap.

Fig. 3

PS-OCT and T1w MRI carpet views for three target nuclei. From top to bottom, each column shows Int, Ret, OA orientation, T1w MRI from the SMAC-MRI63 template registered to pre-op MRI, and the corresponding binary tissue barcodes derived from the PS-OCT retardance and T1w profile. Colorbars for each modality are shown on the right.

Fig. 4

Tissue photographs, corresponding brain atlas sections, and the OA carpet views for three distinct trajectories: (a) GPe, (b) CD, and (c) STN. Dashed black rectangles highlight the imaged regions, whereas red outlines mark specific WM anatomical landmarks in the brain atlas. The yellow shaded areas denote the target regions. The scale bar represents 5 mm, and the annotated tissue structures are as follows: CD, caudate tail (CDt), GPe, GPi, IC, PUT, and STN. The two-way red arrows indicating spatial correspondence between the tissue photographs and OA maps.