<International Circulation>: How are the current situation and the perspectives of myocardial contrast echocardiography right now?

　　Prof. Jim Thomas: Myocardial contrast echocardiography is one of the more interesting tales of the echo world of the last 20 to 25 years. What we’ve been talking about is the use of very tiny micro-bubbles that are around the size of a red blood cell， 2 to 6 microns in diameter， which are able to freely pass through the pulmonary vasculature and will pacify the left side of the heart.

　　There is proven value in myocardial contrast for better definition of left ventricular wall motion， for really defining the endocardiol border in patients that have poor echocardiographic windows. That’s something that we use every day in our echolab， probably in 10 to 15 percent of our echocardiograms. We really could not function as a lab without it.

　　A very interesting application would be to look for myocardial perfusion by myocardial contrast echocardiography. That is something that has been under development for the last 20 or more years， and has certainly been proven in a handful of laboratories around the world among investigators that are really dedicated to the practice of this， that it can be done accurately. It has proven to be quite difficult to branch out into the wider community of echo-laboratories， and also to get FDA approval for this， so at this point it is still an investigational procedure， though one that we still have hope looking forward.