Purpose MRI may cause brain tissue around deep stimulation (DBS) electrodes to become excessively hot, causing lesions. The presence of extracranial loops in the DBS lead trajectory has been shown affect specific absorption rate (SAR) radiofrequency energy at electrode tip, but experimental studies have reported controversial results. goal this study was perform a systematic numerical provide better understanding effects leads on local SAR during 64 and 127 MHz. Methods A total 160...

Purpose MRI of patients with deep brain stimulation (DBS) implants is strictly limited due to safety concerns, including high levels local specific absorption rate (SAR) radiofrequency (RF) fields near the implant and related RF-induced heating. This study demonstrates feasibility using a rotating linearly polarized birdcage transmitter 32-channel close-fit receive array significantly reduce SAR in DBS patients. Methods Electromagnetic simulations phantom experiments were performed generic...

Deep Brain Stimulation (DBS) is increasingly used to treat a variety of brain diseases by sending electrical impulses deep nuclei through long, electrically conductive leads. Magnetic resonance imaging (MRI) patients pre- and post-implantation desirable target position the implant, evaluate possible side-effects examine DBS who have other health conditions. Although MRI preferred modality for pre-operative planning, limited due risk high local power deposition, therefore tissue heating, at...

Abstract Patients with deep brain stimulation (DBS) implants may be subject to heating during MRI due interaction excitatory radiofrequency (RF) fields. Parallel RF transmit (pTx) has been proposed minimize such RF-induced in preliminary proof-of-concept studies. The present work evaluates the efficacy of pTx technique on realistic lead trajectories obtained from nine DBS patients. Electromagnetic simulations were performed using 4- and 8-element coils compared a standard birdcage coil...

Patients with implanted medical devices such as deep brain stimulation or spinal cord are often unable to receive magnetic resonance imaging (MRI). This is because, once the device within radio frequency (RF) field of MRI scanner, electrically conductive leads act antenna, amplifying RF energy deposition in tissue and causing possible excessive heating. Here, we propose a novel concept lead design which 40-cm wires coated ~1.2-mm layer high dielectric constant material (155 <; ε <sub...

Elongated implanted conductors can interact with the radiofrequency (RF) transmission field during MRI, posing safety concerns of excessive heating in patients deep brain stimulators. A technique using parallel RF (pTx) is evaluated on an anthropomorphic heterogeneous model bilateral and unilateral curved wires.Amplitude phase were optimized by simulation to minimize surrounding wires B1+ inhomogeneity for four-channel eight-channel pTx a model. MRI experiments conducted equivalent test...

Patients with deep brain stimulation (DBS) implants can significantly benefit from magnetic resonance imaging (MRI), however access to MRI is restricted in these patients because of safety concerns due RF heating the leads. Recently we introduced a patient-adjustable reconfigurable transmit coil for low-SAR DBS at 1.5T. A previous simulation study demonstrated substantial reduction local SAR around single leads 9 unilateral lead models. This work reports first experimental results...

Patients with deep brain stimulation (DBS) implants have limited access to MRI due safety concerns associated RF-induced heating. Currently, in these patients is allowed 1.5T horizontal bore scanners utilizing pulse sequences reduced power. However, the use of 3T such increasingly reported based on assessments. Here we present results comprehensive RF heating measurements for two commercially available DBS systems during at and 3T.To assess effect imaging landmark, lead configuration,...

Patients with active implants such as deep brain stimulation (DBS) devices are often denied access to MRI due safety concerns associated the radiofrequency (RF) heating of their electrodes. The majority studies on RF conductive have been performed in horizontal close-bore scanners. Vertical scanners which a 90° rotated transmit coil generate fundamentally different electric and magnetic field distributions, yet very little is known about this class We numerical simulations well phantom...

Purpose To evaluate the local specific absorption rate (SAR) and heating around retained cardiac leads during MRI at 64 MHz (1.5T) 127 (3T) as a function of RF coil type imaging landmark. Methods Numerical models were built from CT X‐ray images 6 patients with leads. Electromagnetic simulations bio‐heat modeling performed body head coils tuned to positioned 9 different landmarks covering an area lower limbs. Results For all both 1.5T 3T, transmit produced negligible temperature rise ( ) for...

Purpose Patients with deep brain stimulation (DBS) implants benefit highly from MRI, however, access to MRI is restricted for these patients because of safety hazards associated RF heating the implant. To date, all studies on medical have been performed in horizontal closed‐bore systems. Vertical scanners a fundamentally different distribution electric and magnetic fields are now available at 1.2T, capable high‐resolution structural functional MRI. This work presents first simulation study...

Ultra-high field MRI at 7 T can produce much better visualization of sub-cortical structures compared to lower field, which greatly help target verification as well overall treatment monitoring for patients with deep brain stimulation (DBS) implants. However, use such is currently contra-indicated by guidelines from the device manufacturers due safety issues. The aim this study was provide an assessment and image quality ultra-high magnetic resonance imaging in We performed experiments both...

Background Since the advent of magnetic resonance imaging (MRI) nearly four decades ago, there has been a quest for ever-higher field strengths. Strong incentives exist to do so, as increasing strength increases signal-to-noise ratio images. However, ensuring patient safety becomes more challenging at high and ultrahigh MRI (i.e., ≥3 T) compared lower fields. The problem is exacerbated patients with conductive implants, such those deep brain stimulation (DBS) devices, excessive local heating...

Planar electrodes are increasingly used in therapeutic neural stimulation techniques such as functional electrical stimulation, epidural spinal cord and cortical stimulation. Recently, optimized electrode geometries have been shown to increase the efficiency of by increasing variation current density on surface. In present work, a new family modified fractal is developed enhance It that promising approach activation function "edginess" surface, concept explained quantified mathematics....

Electrical stimulation of the central and peripheral nervous systems - such as deep brain stimulation, spinal cord epidural cortical are common therapeutic options increasingly used to treat a large variety neurological psychiatric conditions. Despite their remarkable success, there limitations which if overcome, could enhance outcomes potentially reduce side-effects. Micromagnetic (μMS) was introduced address some these limitations. One most properties is that μMS theoretically capable...

Patients with active implants such as deep brain stimulation (DBS) devices have limited access to magnetic resonance imaging (MRI) due risks associated RF heating of in MRI environment. With an aging population and increased prevalence neurodegenerative disease, the indication for exams patients increases well. In response this growing need, many groups investigated strategies mitigate DBS during MRI. These efforts fall into two main categories: field-shaping methods, where electric field...

Interaction of an active electronic implant such as a deep brain stimulation (DBS) system and MRI RF fields can induce excessive tissue heating, limiting accessibility. Efforts to quantify heating mostly rely on electromagnetic (EM) simulations assess individualized specific absorption rate (SAR), but require extensive computational resources. Here, we investigate if predictive model using machine learning (ML) predict the local SAR in around tips implanted leads from distribution tangential...

The majority of studies that assess magnetic resonance imaging (MRI) induced radiofrequency (RF) heating the tissue when active electronic implants are present have been performed in horizontal, closed-bore MRI systems. Vertical, open-bore systems a 90° rotated magnet and fundamentally different RF coil geometry, thus generating substantially field distribution inside body. Little is known about elongated such as deep brain stimulation (DBS) devices this class scanners. Here, we conducted...

Deep brain stimulation (DBS) is a well-established treatment for Parkinson's disease, essential tremor and dystonia.It has also been successfully applied to treat various other neurological psychiatric conditions including depression obsessive-compulsive disorder.Numerous computational models, mostly based on the Finite Element Method (FEM) approach have suggested investigate biophysical mechanisms of electromagnetic wave-tissue interaction during DBS.These although emphasizing importance...

Radiofrequency (RF) tissue heating around deep brain stimulation (DBS) leads is a well-known safety risk during MRI, resulting in strict imaging guidelines and limited allowable protocols. The implanted lead's trajectory orientation with respect to the MRI electric fields contribute variations magnitude of RF across patients. Currently, there are no surgical requirements for implanting extracranial portion DBS lead, substantial clinical lead trajectories consequently heating. Recent studies...