Abstract
For the purpose of visualization and measurement of the intracardiac blood flow, contrast cardiotomography which is a method of recording simultaneously the intracardiac blood flow and cross section pictures of the heart in dynamic status by using the ultrasonic pulse reflection technique is investigated. From the fundamental experiment, it is confirmed that saline is the most suitalbe material for producing the artificial contrast echoes in the blood because it differs in acoustic impedance from the blood and is harmless fo patients.
In clinical application of this method, about 10 to 15 cc of saline is injected into the cardiac chambers through the catheter or a peripheral rein which a ultrasonic cardiotomogram is continuously displayed on the CRT screen by a high speed sector scanning. Artificial echoes are produced in the cardiac chambers just after injection of the saline and flow together with the intracardiac blood stream. Thus we can easily determine the direction, flowing status, and timing of the occurrence of an abnormal flow in the cardiac chambers in such cases with a regurgitant flow in valvular diseases and with a shunt flow in congenital heart diseases.
Furthermore, according to this method utilizing the M-mode, the direction and flowing status such as eddy or jet can be identified by the echo pattern in more details. Also the flow velocity can be determined by measuring the inclination of the M-mode pattern.
