Magnetic resonance-guided transcranial focused ultrasound (MRgFUS) represents one of the most notable advances in the interface between neurotechnology and clinical therapeutics. This minimally invasive method allows the precise ablation or modulation of deep brain structures, using real-time magnetic resonance imaging (MRI) to guide and monitor the application of high-intensity ultrasound waves. Its clinical application is already consolidated in the treatment of movement disorders, such as essential tremor (ET) and Parkinson’s disease (PD), with FDA approval for ablation of the ventral nucleus intermedius (Vim) and globus pallidus internus (GPi) in cases refractory to conventional therapies (Kamimura & Sokolov, 2025).
One of the major advantages of MRgFUS compared to other neurosurgical interventions, such as deep brain stimulation (DBS), is its noninvasive nature and the absence of permanent implants, which reduces the risk of postoperative complications and eliminates the need for chronic maintenance. Additionally, the use of resonance thermometry allows precise thermal control, minimizing damage to adjacent tissues. However, it is worth noting that thermal ablation is irreversible and, if poorly directed, can result in lasting neurological deficits — hence the importance of continuous improvements in imaging techniques, targeting, and therapeutic planning algorithms (Kamimura & Sokolov, 2025).
Available clinical evidence demonstrates that unilateral Vim ablation by MRgFUS provides sustained relief of motor symptoms in ET, with generally mild and transient side effects. Five-year follow-up data indicate significant maintenance of motor improvement and absence of progressive or late complications. Furthermore, bilateral application in stages, with a minimum interval of nine months between procedures, has been shown to be effective and safe, with predominantly reversible adverse events, such as dysarthria, paresthesia and postural instability (Kamimura & Sokolov, 2025).
The expansion of MRgFUS technology to alternative targets, such as the cerebellothalamic tract (CTT), the subthalamic nucleus (STN) and the pallidothalamic tract (PTT), opens new therapeutic perspectives, especially in tremor subtypes or parkinsonian symptoms unresponsive to Vim ablation. Recent clinical trials also point to its potential to treat neuropathic pain, epilepsy, psychiatric disorders (such as OCD and resistant depression) and even pathologies in pediatric populations – which demonstrates the plasticity and versatility of this approach (Kamimura & Sokolov, 2025).
Despite advances, MRgFUS still faces technical challenges, especially related to the variability of cranial anatomy and the attenuation of ultrasound energy by bone. The bone density ratio (SDR) and other skull characteristics, such as thickness and angle of incidence of waves, directly impact the efficacy of focusing. Cavitation detection systems, pseudo-CT correction algorithms, and new approaches with artificial intelligence are being developed to optimize the planning and delivery of therapeutic energy, reducing risks and expanding patient eligibility (Kamimura & Sokolov, 2025).
Looking ahead, the integration of emerging technologies such as ultra-high-field MRI (7T or higher), artificial intelligence for predicting optimal treatment targets and parameters, and portable devices for tremor assessment and efficacy monitoring, promises to further boost the applicability of MRgFUS. Additionally, strategies such as temporary opening of the blood-brain barrier and therapeutic sonodynamics (TDS) position focused ultrasound as a versatile platform for personalized therapies in the field of neurology and neurooncology.
In summary, MRgFUS represents not only a new frontier in neurotherapies, but a transformative paradigm that converges technological innovation, safety, and clinical efficacy. Although challenges persist, the disruptive potential of this approach is evident, especially in a medicine that is increasingly moving towards precise, minimally invasive, and real-time image-guided interventions.
Reference:
KAMIMURA, HAS; SOKOLOV, A. Transcranial magnetic resonance-guided focused ultrasound for neurological applications: industry challenges, innovations, and future directions. Journal of Neural Engineering, [Sl], v. 22, n. 2, p. 021003, 2025. DOI: https://doi.org/10.1088/1741-2552/adc8d2. Available at: https://doi.org/10.1088/1741-2552/adc8d2. Accessed on: Apr. 23, 2025.
