1. A method for detecting a stenosis, comprising the steps of: (a) generating ultrasound data reflected from an internal site using an ultrasound machine including an ultrasound transducer; (b) extracting tissue vibration data from the ultrasound data using a vibration processor where components due to transducer movement, respiration and cardiac pulsation are minimized in the tissue vibration data, such that the tissue vibration data corresponds to vibrations caused by the stenosis; and (c) outputting an indication of the tissue vibration data to a user in a format perceptible to the user, wherein the indication conveys to the user that a stenosis is present at the internal site.