Digital analysis of myocardial contrast echocardiography: A clinical studyusing an air-filled agent in normal subjects

The purpose of the present study was to determine whether direct digital im age analysis would allow improved detection of myocardial contrast. Eightee n normal subjects were recruited and separated into two groups. In group I, the time-brightness curves of the left ventricular cavity and three myocar dial perfusion beds were formed from digitized video tape, with output powe r and imaging time as secondary variables. In group 2, curves constructed f rom direct polar digital data were compared, with, fundamental and second h armonic image formation as variables. In group I subjects, using fundamenta l imaging, the area under the cui-ve in the left ventricular cavity increas ed slightly with intermittent imaging. No consistent myocardial opacificati on was identified. In, group 2 subjects, using intermittent imaging, the ar ea under the myocardial curve and peak intensity increased with high output , second harmonic imaging in, the left anterior descending and right corona ry artery regions. Intermittent, second harmonic imaging and digital proces sing can demonstrate myocardial contrast even with an air-filled agent.