Imaging of the Centromedian Thalamic Nucleus using 3D Fast Gray Matter Acquisition T1 Inversion Recovery Sequence in 3T MRI in Epilepsy

Background: The centromedian thalamic nucleus (CM) is an emerging deep brain stimulation (DBS) target for neurological disorders, including drug-resistant epilepsy. Traditional DBS localization relies on predefined stereotactic coordinates, which may be imprecise. Novel MRI sequences enhance gray-white matter contrast, potentially allowing direct CM visualization, improving accuracy in DBS planning and targeting. Objective: This study evaluates the 3D Fast Gray Matter Acquisition T1 Inversion Recovery (FGATIR) MRI sequence for the visualization of the CM in epilepsy patients. Methods: This prospective IRB-approved descriptive study included adult epilepsy patients who underwent 3D FGATIR MRI sequence at 3 Tesla. Two neuroradiologists independently assessed CM visualization using qualitative grading and quantitative measurements of signal-to-noise (SNR) and contrast-to-noise ratios (CNR) of the CM and three neighboring nuclei, including the mediodorsal (MD), medial pulvinar (PuM), and ventrolateral (VL) nuclei in each thalamus. Interobserver agreement for quantitative assessment was evaluated using the intraclass correlation coefficient. Results: A total of 16 epilepsy patients (mean age 42.8 ± 21.3 years, 44% male) were included. The qualitative assessment showed good CM visualization in 84% and poor CM visualization in 16% of cases. Mean signal intensities and SNRs differed significantly between CM and other neighboring thalamic nuclei (p < 0.001). CNRs of the CM relative to MD, PuM, and VL varied across both thalami. Interobserver agreement was excellent, with ICC > 0.95 for all measurements. Conclusion: The 3D FGATIR MRI sequence is a practical tool to visualize the CM. Its adoption in clinical practice could potentially improve DBS planning.