What is the substance applied to the abdomen during ultrasound and color Doppler ultrasound?

Patient's question:

No

Doctor's answer:

It is a ultrasonic coupling agent, which has no effect on the human body. The coupling agent is a medical product composed of a new generation of aqueous polymer gel. It has a neutral pH value, is non-toxic and harmless to the human body, is not easily dried, is not easily acidified, and provides clear ultrasound imaging.