Thyroid examination techniques

The thyroid gland is located below the neck, on both sides of the respiratory tract. It produces protein and regulates metabolic rate. Thyroid disease is a common physiological disease in our lives caused by abnormalities in the thyroid gland, and its main symptoms include physical fatigue and mental irritability. If not treated promptly, there is even the possibility of developing thyroid cancer. Then it is necessary to understand the examination methods of thyroid gland.

Thyroid cancer screening includes the following:

1. X-ray film

(1) The neck is straight. A giant thyroid gland can show the outline of soft tissue and calcification shadows, which are patchy and have a relatively uniform density. X-ray films of malignant tumors often appear cloudy or granular, with irregular boundaries. The relationship between the trachea and the thyroid gland can be understood through the frontal and lateral views of the neck. Benign thyroid tumors or nodular goiters can cause tracheal displacement, but generally do not cause stenosis. Advanced thyroid cancer infiltration of the trachea can cause tracheal stenosis, but the degree of displacement is relatively mild.

(2) Chest and bone X-rays: Routine chest X-rays can be used to determine whether there is lung metastasis, and bone X-rays can be used to determine whether there is bone metastasis. Bone metastasis occurs in the skull and is mainly osteolytic destruction without periosteal reaction, which may invade adjacent soft tissues.

2. CT scan

On CT images, thyroid cancer appears as a blurred boundary within the thyroid gland, with calcification points sometimes visible. Adjacent organs such as the trachea and the trachea can also be observed. It often protrudes beyond the thyroid area, with unclear density and boundary with surrounding tissues. Metastatic lesions may also be found, with no enhancement in cystic changes and necrotic areas. Advanced cancer metastases to the lungs, skull, and bones can also be displayed, and the patient's prognosis can be evaluated.

3. B-ultrasound and color Doppler ultrasound examination

Ultrasound examination has a high resolution for soft tissue, and its positive rate is better than that of X-ray examinations. It can distinguish cystic and solid tumors with an accuracy rate of 80 to 90 percent. The capsule of thyroid cancer nodules is incomplete or absent, and may show crab-like changes and sand-like calcifications. It is more common in papillary carcinoma, and cyst images are less common. There is an arterial blood flow spectrum in the tumor, and enlarged lymph nodes can be found. The longitudinal diameter of the lymph nodes is 2: the transverse diameter. The blood flow signal distribution is disordered, which is manifested as interruption of the echo of the thyroid capsule or internal jugular vein. If it metastasizes to the internal jugular vein, it will appear low. Color Doppler ultrasound can show dot-like or strip-like blood flow signals.

4. Radionuclide examination

The thyroid gland has the function of absorbing and concentrating iodine. After radioactive iodine enters the human body, most of it is distributed in the thyroid gland, which can display the morphology of the thyroid gland and measure the iodine uptake rate of the thyroid gland. However, some thyroid cancers have poor 131I uptake function, so other methods should be used. SPECT) to diagnose thyroid tumors has improved the diagnostic effect. There are two main methods.

(1) Static imaging of the thyroid gland: It can show the location of the thyroid gland and the distribution of radioactivity within the thyroid gland. It can also show thyroid tumors. If the right lobe is small and the left lobe is slightly larger, thyroid metastatic cancer should be considered.

According to the functional status of thyroid nodules, they can be divided into: hot nodules, in which the nodules appear densely in the image, which is significantly higher than the normal thyroid tissue. Most of them are functional autonomous adenomas, but a few can also be cancer. In the image, the imaging agent accumulated in the nodule tissue is close to that in the normal thyroid tissue. Generally, most of them are thyroid adenomas, but a few can also be cancer. The nodule site has no function of accumulating imaging agent, and the image shows a radioactive distribution defect in the nodule site, which is common in thyroid cancer. Benign lesions such as thyroid adenomas can also show cold/cool nodules, which only indicates the functional status of the nodule tissue's uptake of 131I and 99mTc, but has no direct connection with the benign or malignant nature of the nodule, and cannot be used as a basis for the diagnosis of thyroid malignant tumors.

(2) Thyroid function imaging: Thyroid cancer tissue has more blood vessels and faster blood flow. Therefore, 99mTc can be used as a contrast agent for dynamic thyroid imaging and differential diagnosis of thyroid nodules. Normal thyroid begins to be imaged at around 16 seconds and gradually intensifies, reaching a peak at around 22 seconds and a peak at 16 seconds. If it is a benign thyroid tumor, the thyroid nodule will not be imaged within 30 seconds.

5. Thyroid magnetic resonance imaging (MRI) High-resolution MRI examination

It can more clearly display the thyroid tumor crown, and can clearly locate the range of lesions and lymph node metastases, better assist in diagnosis, and guide the selection of treatment methods, mainly looking at the invasion of thyroid cancer on adjacent muscle tissue, lymph nodes and other parts, as well as the evaluation of postoperative recurrence.

Through the above introduction to thyroid cancer, we have learned the reasons for the examination of thyroid cancer. We should pay attention to these factors and stay away from the causes of thyroid cancer.