Left-Ventricular Mechanical Activation and Aortic-Arch Orientation Recovered from Magneto-Hydrodynamic Voltages Observed in 12-Lead ECGs Obtained Inside MRIs: A Feasibility Study

T. Stan Gregory, Ehud J. Schmidt, Shelley Hualei Zhang, Raymond Y. Kwong, William G. Stevenson, Jonathan R. Murrow, Zion Tsz Ho Tse

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

To explore use of the Magnetohydrodynamic Voltage (VMHD), observed in intra-MRI 12-lead electrocardiograms (ECG), to indicate the timing of the onset of left-ventricular mechanical activation (LVMA) and the orientation of the aortic-arch (AAO). Blood flow through the aortic arch during systole, in the presence of the MRI magnetic field (B0), generates VMHD. Since the magnitude and direction of VMHD are determined by the timing and directionality of blood flow relative to B0, we hypothesized that clinically useful measures, LVMA and AAO, could be extracted from temporal and vectorial VMHD characteristics. VMHD signals were extracted from 12-lead ECG traces by comparing traces obtained inside and outside the MRI scanner. VMHD was converted into the Vectorcardiogram frame of reference. LVMA was quantified in 1 subject at 1.5T and 3 subjects at 3T, and the result compared to CINE MRI. AAO was inferred for 4 subjects at 3T and compared to anatomical imaging of the aortic arch orientation in the transverse plane. A < 10% error was observed in LVMA measurements, while a < 3° error was observed in aortic arch orientation measurements. The temporal and vectorial nature of VMHD is useful in estimating these clinically relevant parameters.

Original languageEnglish (US)
Pages (from-to)2480-2489
Number of pages10
JournalAnnals of Biomedical Engineering
Volume42
Issue number12
DOIs
StatePublished - Nov 21 2014
Externally publishedYes

Keywords

  • 12-Lead Electrocardiogram
  • Cardiac MRI
  • ECG
  • High-field MRI
  • MHD
  • Magnetohydrodynamic
  • Mechanical activation
  • Orientation

ASJC Scopus subject areas

  • Biomedical Engineering

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