Do I need to apply coupling agent for physical examination and color ultrasound?

Physical examination and color ultrasound usually require the application of a coupling agent to eliminate the air gap between the probe and the skin, ensuring clear images.

Couplant is a water-based gel, mainly composed of water, glycerin and a small amount of preservatives, which is non irritating to human body. During ultrasound examination, direct contact between the probe and the skin can cause ultrasound reflection due to residual air, which affects the imaging quality. Coupling agents can fill small depressions in the skin, forming a uniform medium for sound wave transmission, allowing high-frequency ultrasound to effectively penetrate tissues. Examination sites such as thyroid, breast, abdomen, etc. need to be used, especially for obese or dry skin. Coupling agents have a lubricating effect, which can reduce the friction sensation when the probe moves and improve the comfort of inspection. Some couplant agents contain thermal insulation components, which can avoid discomfort caused by low temperature gel. The coupling agent can be easily wiped clean with a tissue after inspection, without residue or damage to clothing. After the physical examination, it is recommended to wear loose clothing to avoid rubbing the examination area. If the skin is sensitive, medical staff can be informed in advance to choose a low sensitivity coupling agent. On the day of the examination, there is no need for fasting or special preparation, but abdominal ultrasound requires holding urine in advance. Coupling agents are disposable medical consumables, and medical institutions will strictly disinfect probes and replace them with newly opened products, so there is no need to worry about the risk of cross infection.