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A 1.5T MRI‐conditional 12‐lead electrocardiogram for MRI and intra‐MR intervention
Author(s) -
Tse Zion Tsz Ho,
Dumoulin Charles L.,
Clifford Gari D.,
Schweitzer Jeff,
Qin Lei,
Oster Julien,
JeroschHerold Michael,
Kwong Raymond Y.,
Michaud Gregory,
Stevenson William G.,
Schmidt Ehud J.
Publication year - 2014
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24744
Subject(s) - magnetic resonance imaging , lead (geology) , qrs complex , medicine , real time mri , biomedical engineering , cardiology , radiology , geomorphology , geology
Purpose High‐fidelity 12‐lead electrocardiogram (ECG) is important for physiological monitoring of patients during MR‐guided intervention and cardiac MRI. Issues in obtaining noncorrupted ECGs inside MRI include a superimposed magneto‐hydro‐dynamic voltage, gradient switching‐induced voltages, and radiofrequency heating. These problems increase with magnetic field. The aim of this study is to develop and clinically validate a 1.5T MRI‐conditional 12‐lead ECG system. Methods The system was constructed with transmission lines to reduce radiofrequency induction and switching circuits to remove induced voltages. Adaptive filters, trained by 12‐lead measurements outside MRI and in two orientations inside MRI, were used to remove the magneto‐hydro‐dynamic voltage. The system was tested on 10 (one exercising) volunteers and four arrhythmia patients. Results Switching circuits removed most imaging‐induced voltages (residual noise <3% of the R‐wave). Magneto‐hydro‐dynamic voltage removal provided intra‐MRI ECGs that varied by <3.8% from those outside the MRI, preserving the true S‐wave to T‐wave segment. In premature ventricular contraction (PVC) patients, clean ECGs separated premature ventricular contraction and sinus rhythm beats. Measured heating was <1.5°C. The system reliably acquired multiphase (steady‐state free precession) wall‐motion‐cine and phase‐contrast‐cine scans, including subjects in whom 4‐lead gating failed. The system required a minimum repetition time of 4 ms to allow robust ECG processing. Conclusion High‐fidelity intra‐MRI 12‐lead ECG is possible. Magn Reson Med 71:1336–1347, 2014. © 2013 Wiley Periodicals, Inc .