A left lobe thyroid nodule is a lump in the left lobe of the thyroid gland. There are many causes of thyroid nodules and many clinical diseases of the thyroid gland, such as thyroid inflammation, degenerative thyroid disease, and autoimmune disorders that can cause thyroid nodules. Thyroid nodules can be solitary or multiple, the difference being that the incidence of multiple thyroid nodules is higher than that of solitary thyroid nodules. The majority of thyroid nodules are benign and malignant, with malignant nodules accounting for only about 5%-15%. The majority of benign thyroid nodules are harmless and do not require treatment. Only nodules that are large enough to cause pressure on the organs around the trachea and are suspected or confirmed to be thyroid cancer require treatment. How to determine the benignity or malignancy of thyroid nodules? Routinely, benign thyroid tumors are soft, while malignant tumors are mostly hard in texture. Ultrasound elastography and ultrasonography enhancement of thyroid nodules are widely used non-invasive and radiation-free methods to differentiate benign and malignant thyroid nodules. Ultrasound contrast enhancement technique is a new non-invasive, radiation-free imaging technique that enhances the blood flow reflection signal of the body by intravenous injection of ultrasound contrast agent on the basis of conventional ultrasound examination.