Siemens color ultrasound is a high-definition black and white B ultrasound plus color Doppler, first of all, ultrasound frequency shift diagnostic method, that is, D ultrasound, this method applies the principle of the Doppler effect, when the source of the sound and the receiver (i.e., probe and reflector) when there is a relative motion between the frequency of the echo has changed, the frequency of this change is called the shift, D ultrasound, including pulsed Doppler, continuous Doppler, and color Doppler blood flow Images. The direction of development of ultrasound in the medical field is color ultrasound, commonly used in obstetrics and gynecology, prostate and seminal vesicles, small organs, abdominal organs and vascular disease.