Multiscale Parameter Estimation (msPE) of QRS complexes distorted by magnetohydrodynamic effects at 7 Tesla

Abstract

During ultra-high-field magnetic resonance imaging, the acquisition of electrocardiography is impeded by artifacts. This poses a challenge in examinations where the QRS complex is used as a trigger for activating image acquisition. In this work, we customize a framework for multiscale parameter estimation for processing electrocardiography signals acquired inside and outside an ultra-high-field scanner bore: The parameters of a QRS complex modeled by a Gaussian function were estimated using scale-dependent algebraic expressions for 600 heartbeats from three subjects. Sensitivity ≥ 94% and accuracy ≤ 5ms in each experiment indicate feasibility of this approach, and, additionally, run time is within the acceptable range for triggering latency in the majority of cases. Hence, we see a real-time implementation as an avenue for future work.

Keywords

• magnetic resonance imaging
• electrocardiography
• artifacts
• wavelet transform
• parameter estimation