Neck ultrasound can be used to check the thyroid gland, carotid artery, and carotid mass, etc. Neck ultrasound is usually used to check the above diseases, and if there is a localized mass, in order to clarify whether it is cystic or solid inside the mass, neck ultrasound is usually needed. Thyroid diseases, such as thyroid nodules, also require neck ultrasound to confirm the extent of the nodules. Stenosis and plaque formation in the carotid arteries also need to be further confirmed by color ultrasound. Therefore, neck ultrasound is applicable to a wide range of conditions and does not cause local trauma to the patient, so it can be used frequently.