Fast coronary Doppler vibrometry to detect myocardial vibration associated with coronary artery stenosis using flash imaging

Recently, a new noninvasive ultrasonic technique called the coronary Doppler vibrometry (CDV) was developed to detect the audio-frequency vibrations in the vessel wall and surrounding tissues generated by the turbulence flow associated with the stenosed artery. Inspiring clinical data for diagnosing coronary artery stenosis (CAS) were obtained from CDV with high sensitivity and specificity. However, there still exists a significant limitation, one of which is the long examination time. In estimating myocardial vibrations, we must extract the myocardial tissue Doppler data from the multiple segments that are adjacent to the coronary artery in each echocardiography view and hence we need to acquire multiple data that are as many as the number of segments. To deal with this problem, we consider the use of unfocused transmission which is called the flash imaging. By using the flash imaging technique, we can interrogate all segments associated the coronary artery by using only one unfocused beam in each echocardiography view, and we need less data acquisitions. As a result, the data acquisition time is reduced significantly and so is the examination time. Vibrations were characterized by the vibration index (VI) computed from the tissue velocity spectrum for diagnosing coronary artery stenosis. The feasibility of the proposed approach was confirmed through a series of the clinical testing.