I think you are referring to an echocardiogram. it does not evaluate coronary artery stenosis or plaque.
there is a test called stress echocardiogram that, in my limited understanding, is one method of indirectly evaluating for coronary artery stenosis. other indirect methods are the standard stress test and radionuclide stress imaging.
I don't know what the medical name is, but it's basically a picture generated with ultrasound; an acoustic real-time image is what it would be called in my profession. I saw my heart beating on the monitor. They do Doppler processing (I assume) and they get an idea of the leakage at the heart valves. The leakage is shown as a different color to the normal blood flow. Some leakage is of course is normal
A specialist analyzed the images (heart and carotids) and pronounced that I had a low level of plaque build up.
I wondered how good it was as it's reasonably priced as far as these things go. Some 11 years ago I had one that missed a prostate cancer, but the biopsy got it a little later. Hopefully, they are a lot better now.
Al