Noninvasively diagnosing coronary artery disease with 61-channel MCG data

Magnetocardiography (MCG) has been investigated as a tool for noninvasive detection of coronary artery disease (CAD). In this study, the area ratio of positive and negative magnetic induction extracted from an extrema circle in the magnetocardiogram was analyzed at specific time points in the cardiac cycle: P maximum, R peak, J point, T onset, T peak and T end. The area of the positive proportion of the magnetic field relative to the total area within a circle encompassing the field extrema was determined and proposed for fast-speed CAD diagnosis. MCG was performed with a 61-channel biomagnetometer in a shielded environment in 38 healthy subjects and 15 CAD patients. A notable difference in area ratio was found between healthy and CAD subjects at the peak time of T wave: 0.416 +/- 0.090 versus 0.465 +/- 0.065 (p = 0.013). Using a cutoff value of 0.4506 resulted in a sensitivity and specificity of 86.7 % and 73.8 %, respectively. This approach may enable a fast-speed CAD diagnosis in a clinical setting.