Final answer:
Pulsed Doppler ultrasound is the best technique for detecting mitral regurgitation, as it can accurately measure the velocity of blood flow and detect abnormal patterns.
Step-by-step explanation:
The best echo technique for the detection of mitral regurgitation is pulsed Doppler ultrasound. This method utilizes the Doppler-shifted ultrasound to detect motion and measure velocity, which is especially useful for evaluating blood flow through the heart valves. By detecting the changes in frequency of the reflected sound waves caused by the movement of blood, pulsed Doppler allows for the assessment of the direction and velocity of blood flow, which can reveal the presence of mitral regurgitation.