Three-Dimensional Reconstruction of a Cardiac Outline by Magnetocardiography

Abstract

A 3-D cardiac visualization is significantly helpful toward clinical applications of magnetocardiography (MCG), but the cardiac reconstruction requires a segmentation process using additional image modalities. This paper proposes a 3-D cardiac outline reconstruction method using only MCG measurement data without further imaging techniques. The cardiac outline was reconstructed by a combination of both spatial filtering and coherence mapping method. The strength of cardiac activities was first estimated by the array-gain constraint minimum-norm spatial filter with recursively updated gram matrix (AGMN-RUG). Then, waveforms were reconstructed at whole source grids, and the maximum source points of an atrium and ventricle were selected as a reference, respectively. Next, the coherence between each maximum source point and whole source points was compared by the coherence mapping method. A reconstructed cardiac outline was validated by comparing with an overlapped volume ratio when the reconstructed volume was identically matched with the original volume. The results obtained by the AGMN-RUG were compared to the results by other spatial filters. The accuracy of numerical simulation and phantom experiment by the AGMN-RUG was superior 10% and 8%, respectively, than the accuracy by the standardized low-resolution electromagnetic tomography. This accuracy demonstrated the efficacy of the proposed 3-D cardiac reconstruction method.

An Interactive Holographic Environment for Visualization of Heart Structure and Activity

“…The three-dimensional reconstruction of a cardiac contour by Magnetocardiography proposed by [16] worked with reconstruction of 3D cardiac contour using only measurement data, without other imaging techniques. The cardiac outline was reconstructed by a combination of spatial filtering method and coherence mapping.…”

Vector magnetocardiography using compact optically-pumped magnetometers

“…In contrast to traditional electrocardiogram techniques, the diagnostic approach using MCG signals presents a notable advantage by minimizing distortions caused by the intricate conductivity distribution within the tissues between the heart's anatomical position and the skin surface. This characteristic can enhance the precision of cardiac source localization and facilitates the establishment of comprehensive cardiac models [ 13 , 14 ]. The utilization of MCG as a diagnostic technique holds promising advantages for the early detection of myocardial ischemia and other indicative symptoms of heart disease [ 15 ].…”

Toward a novel semi‐invasive activation mapping tool for the diagnosis of supraventricular arrhythmias from the esophagus

“…On the forefront of the field are electrocardiographic imaging (ECGI) systems, which combine multi-electrode measurements from up to 252 body surface electrodes with patient-specific anatomical information from computed tomography (CT) imaging to reconstruct epicardial depolarization sequences (Rudy, 2013;Shah, Hocini, Xhaet, et al, 2013). Alternative approaches include measurements of the heart magnetic field (Ha, Kim, Lim, Yu, & Kwon, 2015;Kim, Kim, Lee, & Ahn, 2007;Sorbo et al, 2018), the exploitation of vectorcardiograms (Castells et al, 2011;Hasan, Abbott, & Baumert, 2012;Man, Maan, Schalij, & Swenne, 2015), or the acquisition of esophageal electrocardiograms (eECGs) (Haeberlin, Niederhauser, et al, 2013;Niederhauser et al, 2012). Esophageal ECGs have interesting properties, the most notable of which is an excellent atrial signal quality.…”