$700,000 (or more, if you haven't already figured in indirects) would be a challenge for a seasoned faculty member to get, and if it is really a small study it will be hard to convince funders that it is worth all the money. If the project is researching something with a strong nonprofit (or profit) interest, it is possible that they'll have more money available, but it will still be hard to convince them that that much money should go to a small study from an unproven researcher (unless you were a faculty member before going to med school and have gotten funding and published on the topic previously). I'm not trying to put you down at all-you should keep your idea on the back burner, but maybe try something more modest in cost initially. Have you talked to someone in your area of research about your ideas? Maybe you can get some developmental funds, or pilot funding, so you'll have some data or background for the preliminary studies. Or maybe analyze some data already available? Or follow patients who were getting echos anyway? Your institution may also have info on non-NIH funding sources. Good luck!