Clinically, for thyroid nodules less than 1 cm that are considered to be cancerous, the following measures can be used to clarify the diagnosis: 1. Ultrasound and ultrasonography of the thyroid gland. If a patient is found to have a nodule with rich blood flow signal, accompanied by pinpoint calcification and a nodule aspect ratio greater than 1, it is highly suspected that the thyroid nodule has become cancerous and surgery is recommended in a timely manner. For nodules without typical malignant signs, ultrasound imaging of thyroid nodules can further reveal the morphological structure of the nodule under the contrast agent to confirm the diagnosis. 2. Ultrasound-guided fine needle aspiration is also commonly used to confirm the nature of the thyroid lesion. If tumor cells are found under the microscope, the diagnosis of cancerous thyroid nodules can be confirmed.