A GROUNDBREAKING study from earlier this year comparing the effectiveness of 7 Tesla (7T) MRI to the more widely used 3 Tesla (3T) MRI for planning deep brain stimulation (DBS) in essential tremor patients has demonstrated significant advantages of 7T imaging. Researchers have revealed that 7T MRI achieves greater precision in electrode placement, improved tremor control, and reduced stimulation currents.
The retrospective study, conducted between 2021 and 2023, analysed outcomes in 34 patients undergoing unilateral thalamic DBS for essential tremor. The patients were divided into two groups of 17, with surgeries planned using either 7T or 3T MRI. The primary outcome measured was the percentage improvement in Fahn-Tolosa-Marin Tremor Rating Scale (TRS) scores, with additional assessments of electrode positioning and stimulation requirements.
Key findings indicated that patients in the 7T group achieved significantly greater tremor reduction, with an average TRS improvement of 64.9% compared to 50.9% in the 3T cohort. Furthermore, the 7T group required lower mean stimulation currents (2.0 ± 0.8 mA) compared to the 3T group (2.7 ± 0.9 mA), highlighting the efficiency of the higher-resolution imaging technique.
Postoperative imaging revealed a striking difference in electrode precision. While mean electrode positions were similar between the groups, 7T electrodes showed significantly less variance, with a mean Euclidean distance from the group centroid of 1.82 mm compared to 2.75 mm for 3T electrodes.
These findings address longstanding concerns about potential imaging artefacts and distortions associated with 7T MRI. Researchers demonstrated that meticulous workflow adjustments effectively mitigate these issues, enabling superior surgical outcomes.
Lead researchers emphasised the potential for 7T MRI to enhance DBS targeting for other neurological conditions. “Our results confirm that 7T MRI offers greater precision in electrode placement, leading to improved patient outcomes,” the authors stated.
Further studies are planned to explore the application of 7T MRI in targeting additional subcortical structures. If confirmed, this could mark a major advancement in neurosurgical imaging and treatment precision.
Reference
Middlebrooks EH et al. Enhancing outcomes in deep brain stimulation: a comparative study of direct targeting using 7T versus 3T MRI. J Neurosurg. 2024;141(1):252-9.
