Determination of three-dimensional torso, heart and electrode geometries from magnetic resonance images

ECG (electrocardiogram) inverse solutions require accurate determination of three-dimensional torso, heart, and electrode geometries. Magnetic resonance imaging (MRI) provides a noninvasive method for obtaining this information. Subjects initially undergo body surface potential mapping using a 195-channel data recording system. Limitations imposed by the intense magnetic field of the imaging system require that the metallic recording electrodes be replaced with nonmetallic oil-filled phantom electrodes. These are easily delineated in the MRI images. Transverse MRI sections of the subject are imaged at 10-mm intervals. Digital data representing the resulting images are transferred to a Macintosh II computer for definition of surface boundaries. This is a practical technique for obtaining geometrical data for ECG inverse solutions.<>