Laleh Golestanirad1,2, Ehsan Kazemivalipour1,3,4, David Lampman5, Hideta Habara6, Ergin Atalar3,4, Joshua Rosenow7, Julie Pilitsis8, John Kirsch9. 1. Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. 2. Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois. 3. Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey. 4. National Magnetic Resonance Research Center (UMRAM), Bilkent University, Ankara, Turkey. 5. Hitachi Healthcare Americas, Twinsburg, Ohio. 6. Hitachi, Ltd. Healthcare Business Unit, Tokyo, Japan. 7. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. 8. Department of Neurosurgery, Albany Medical Center, Albany, New York. 9. A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, Massachusetts.
Abstract
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 with RF heating of the implant. To date, all MRI studies on RF heating of medical implants have been performed in horizontal closed-bore systems. Vertical MRI scanners have a fundamentally different distribution of electric and magnetic fields and are now available at 1.2T, capable of high-resolution structural and functional MRI. This work presents the first simulation study of RF heating of DBS implants in high-field vertical scanners. METHODS: We performed finite element electromagnetic simulations to calculate specific absorption rate (SAR) at tips of DBS leads during MRI in a commercially available 1.2T vertical coil compared to a 1.5T horizontal scanner. Both isolated leads and fully implanted systems were included. RESULTS: We found 10- to 30-fold reduction in SAR implication at tips of isolated DBS leads, and up to 19-fold SAR reduction at tips of leads in fully implanted systems in vertical coils compared to horizontal birdcage coils. CONCLUSIONS: If confirmed in larger patient cohorts and verified experimentally, this result can open the door to plethora of structural and functional MRI applications to guide, interpret, and advance DBS therapy.
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 with RF heating of the implant. To date, all MRI studies on RF heating of medical implants have been performed in horizontal closed-bore systems. Vertical MRI scanners have a fundamentally different distribution of electric and magnetic fields and are now available at 1.2T, capable of high-resolution structural and functional MRI. This work presents the first simulation study of RF heating of DBS implants in high-field vertical scanners. METHODS: We performed finite element electromagnetic simulations to calculate specific absorption rate (SAR) at tips of DBS leads during MRI in a commercially available 1.2T vertical coil compared to a 1.5T horizontal scanner. Both isolated leads and fully implanted systems were included. RESULTS: We found 10- to 30-fold reduction in SAR implication at tips of isolated DBS leads, and up to 19-fold SAR reduction at tips of leads in fully implanted systems in vertical coils compared to horizontal birdcage coils. CONCLUSIONS: If confirmed in larger patient cohorts and verified experimentally, this result can open the door to plethora of structural and functional MRI applications to guide, interpret, and advance DBS therapy.
Authors: Clare E McElcheran; Benson Yang; Kevan J T Anderson; Laleh Golestanirad; Simon J Graham Journal: Magn Reson Med Date: 2017-02-28 Impact factor: 4.668
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Authors: Laleh Golestanirad; Ehsan Kazemivalipour; Boris Keil; Sean Downs; John Kirsch; Behzad Elahi; Julie Pilitsis; Lawrence L Wald Journal: PLoS One Date: 2019-08-07 Impact factor: 3.240
Authors: Alexandre Boutet; Clement T Chow; Keshav Narang; Gavin J B Elias; Clemens Neudorfer; Jürgen Germann; Manish Ranjan; Aaron Loh; Alastair J Martin; Walter Kucharczyk; Christopher J Steele; Ileana Hancu; Ali R Rezai; Andres M Lozano Journal: Radiology Date: 2020-06-23 Impact factor: 11.105
Authors: Bach T Nguyen; Bhumi Bhusal; Amir Ali Rahsepar; Kate Fawcett; Stella Lin; Daniel S Marks; Rod Passman; Donny Nieto; Richard Niemzcura; Laleh Golestanirad Journal: Magn Reson Med Date: 2021-12-27 Impact factor: 3.737