Recommended citation for the data: Sadeghi-Tarakameh, Alireza; DelaBarre, Lance; Zulkarnain, Nur Izzati Huda; Harel, Noam; Eryaman, Yigitcan. (2023). Deep Brain Stimulation (DBS) and Implant-friendly (IF) Mode Calculator. Retrieved from the Data Repository for the University of Minnesota, https://doi.org/10.13020/h56h-bd77. ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: Deep Brain Stimulation (DBS) and Implant-friendly (IF) Mode Calculator 2. Author Information Author Contact: Alireza Sadeghi-Tarakameh (sadeg032@umn.edu) Name: Alireza Sadeghi-Tarakameh Institution: University of Minnesota Email: sadeg032@umn.edu ORCID: 0000-0001-5718-6553 Name: Lance DelaBarre Institution: University of Minnesota Name: Nur Izzati Huda Zulkarnain Institution: University of Minnesota Name: Noam Harel Institution: University of Minnesota Name: Yigitcan Eryaman Institution: University of Minnesota Email: yigitcan@umn.edu 3. Date published or finalized for release: 2023-07-20 4. Date of data collection: Feb 2021 to May 2023 5. Geographic location of data collection: University of Minnesota, Minneapolis, MN 6. Information about funding sources that supported the collection of the data: NIH R01 NS115180, NIH P41 EB027061 7. Overview of the data (abstract): Purpose: The purpose of this study is to present a strategy to calculate the implant-friendly (IF) excitation modes—which mitigate the radiofrequency (RF) heating at the contacts of deep brain stimulation (DBS) electrodes—of multi-channel RF coils at 7T. Methods: An induced RF current on an implantable electrode generates a scattered magnetic field whose left-handed circularly polarizing component (B1+) is approximated using a -mapping technique and subsequently utilized as a gauge for the electrode’s induced current. Using this approach, the relative induced currents due to each channel of a multi-channel RF coil on the DBS electrode were calculated. The IF modes of the corresponding multi-channel coil were determined by calculating the null space of the relative induced currents. The proposed strategy was tested and validated for unilateral and bilateral commercial DBS electrodes (directional lead, Infinity DBS system, Abbott Laboratories) placed inside a uniform phantom by performing heating and imaging studies on a 7T MRI scanner using a 16-channel transceive RF coil. Results: Individual IF modes nor shim solutions obtained from IF modes did not induce significant temperature increase when used for a high-power Turbo Spin Echo sequence. In contrast, shimming with the scanner’s toolbox (i.e., based on per-channel B1+ fields) resulted in a more than 2°C temperature increase for the same amount of input power. Conclusion: A strategy for calculating the IF modes of a multi-channel RF coil is presented. This strategy was validated using a 16-channel RF coil at 7T for unilateral and bilateral commercial DBS electrodes inside a uniform phantom. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC0 1.0 Universal (http://creativecommons.org/publicdomain/zero/1.0/) 2. Links to publications that cite or use the data: Sadeghi-Tarakameh A, DelaBarre L, Zulkarnain NI, Harel N, Eryaman Y. Implant-friendly MRI of deep brain stimulation electrodes at 7 T. Magnetic Resonance in Medicine. 2023 Dec;90(6):2627-42. https://doi.org/10.1002/mrm.29825 3. Was data derived from another source? No If yes, list source(s): 4. Terms of Use: Data Repository for the U of Minnesota (DRUM) By using these files, users agree to the Terms of Use. https://conservancy.umn.edu/pages/drum/policies/#terms-of-use --------------------- DATA & FILE OVERVIEW --------------------- File List A. Filename: Data_extractor_Lead1.m Short description: Type: "MATLAB code", Input: "DICOM files corresponding to the relative B1 mapping", Output: "B1_Lead1_Chs.mat", Description: "Complex B1 maps around the first DBS electrode corresponding to each channel" B. Filename: Current_Zero_modes_calculator_Lead1.m Short description: Type: "MATLAB code", Input: "B1_Lead1_Chs.mat (output of the Step A)", Output: "Currents_Lead1.mat", Description: "Current induced on the first DBS electrode due to each channel's excitation relative to the first channel excitation" C. Filename: NullSpace_of_current_Lead1.m Short description: Type: "MATLAB code", Input: "Currents_Lead1.mat (output of the Step B)", Output: "NullSpace_Lead1.mat",Description: "Null space of the current comprised of the implant-friendly modes (I=0) for the first electrode (IF1 modes)" D. Filename: Data_extractor_Lead2.m Short description: Type: "MATLAB code", Input: "DICOM files corresponding to the relative B1 mapping", Output: "B1_Lead2_IF1.mat", Description: "Complex B1 maps around the second DBS electrode corresponding to each IF1 modes" E. Filename: Current_Zero_modes_calculator_Lead2.m Short description: Type: "MATLAB code", Input: "B1_Lead2_IF1.mat (output of the Step D)", Output: "Currents_Lead2.mat", Description: "Current induced on the second DBS electrode due to each IF1 mode excitation relative to the first IF1 mode excitation" F. Filename: NullSpace_of_current_Leads.m Short description: Type: "MATLAB code", Input: "Currents_Lead2.mat (output of the Step E)", Output: "INullSpace.mat", Description: "Null space of the current comprised of the IF modes for both leads" Filename: Readme.txt Short description: Description of data 2. Relationship between files: It is provided in the short description of each file. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: complex relative B1+ maps corresponding to each Tx channel were acquired on two axial planes—one plane (P2) intersecting one of the electrodes at the shaft and the other plane (P1) underneath the tip of the same electrode—using consecutive fast, low-flip-angle gradient-echo sequences. For the detailed workflow, please see the Figure 2 of the cited publication. 2. Methods for processing the data: Only MATLAB (2019a) codes are submitted, and the corresponding descriptions are provided. The code that supports the findings of this study is openly available at https://github.com/AliSaMRI/DBS_IF_Mode_Calculator 3. Instrument- or software-specific information needed to interpret the data: Implementation of the manuscript entitled "Implant-Friendly MRI of Deep Brain Stimulation Electrodes at 7T": **Perform B1 mapping on two planes (P1:tip & P2:shaft given in the manuscript) then run the sctripts in this order: A. Data_extractor_Lead1.m --> output: B1_Lead1_Chs.mat "B1 maps corresponding to each channel" B. Current_Zero_modes_calculator_Lead1.m --> output: Currents_Lead1.mat "corresponding to each channel" C. NullSpace_of_current_Lead1.m --> output: INullSpace_Lead1.mat "Null space of the current comprised of the implant-friendly modes (I=0) for lead 1" **If this is a unilateral configuration stop here, otherwise proceed to calculate the IF modes for lead 2 D. Data_extractor_Lead2.m --> output: B1_Lead2_IF1.mat "B1 maps corresponding to IF modes of lead 1" E. Current_Zero_modes_calculator_Lead2.m --> output: Currents_Lead2.mat "corresponding to IF modes for Lead 1" F. NullSpace_of_current_Leads.m --> output: INullSpace.mat "Null space of the current comprised of the IF modes for both leads" Now, you can use the implant-friendly modes with any suitable shimming scenarios. 4. Standards and calibration information, if appropriate: N/A 5. Environmental/experimental conditions: All experiments and data collection were performed in vitro. 6. Describe any quality-assurance procedures performed on the data: N/A 7. People involved with sample collection, processing, analysis and/or submission: Alireza Sadeghi-Tarakameh, Lance DelaBarre, Nur Izzati Huda Zulkarnain, Noam Harel, Yigitcan Eryaman