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Introduction ⬇

A thyroid (neck) ultrasound is a noninvasive imaging study that is performed to evaluate a neck mass, distinguish cysts from thyroid nodules, or to determine the size of the thyroid and reveal the depth and dimension of thyroid goiters and nodules. The response of a mass in the thyroid to suppressive therapy can be monitored by successive examinations. Theoretically, this technique offers the possibility of a good estimation of thyroid weight—information that is important in radioiodine therapy for Graves disease.

The examination is easy to do, is often done before surgery, and gives 85% accuracy. Often, these studies are done in conjunction with radioactive iodine uptake tests. With pregnant patients, ultrasound studies are the method of choice because radioactive iodine is harmful to the developing fetus.

Procedure ⬆ ⬇

  1. Have the patient lie supine on the examining table, with the neck hyperextended.

  2. Place a pillow under the shoulders for comfort and to bring the transducer into better contact with the thyroid.

  3. Apply a couplant (ultrasound gel) to the patient’s neck. Move the transducer across the neck’s surface. An alternate procedure involves separation of the neck surface from the transducer by a gel-filled pad that permits proper transmission of the ultrasound waves through the thyroid.

  4. Tell the patient that the examination time is about 30 minutes.

  5. See Chapter 1 guidelines for intratest care.

Procedural Alert

Thyroid or neck biopsies are often performed with ultrasound guidance. If a biopsy is performed, a signed, witnessed consent form must be obtained

Clinical Implications ⬆ ⬇

  1. An abnormal pattern may consist of a cystic, complex, or solid echo pattern.

  2. Solitary “cold” nodules identified on radioisotope scans may appear as echo-free cysts on ultrasound. Most often, cysts are benign. Solid-appearing lesions may represent benign adenomas or malignant tumors. A biopsy is the only definitive method to determine the nature of such tumors.

  3. Overall gland enlargement is indicative of goiter or thyroiditis.

  4. Ultrasound studies of the neck may also reveal parathyroid lesions or evidence of changed lymph nodes.

  5. Certain congenital deformities related to the embryologic development of neck structures may be detected, most commonly thyroglossal duct cyst, branchial cleft cyst, or cystic hygroma (congenital multiloculated lymphatic lesion).

Interventions ⬆ ⬇

Pretest Patient Care

  1. Explain the purpose and procedure of the test.

  2. Assure the patient that there is no pain involved; however, it may be uncomfortable maintaining the neck position during the examination.

  3. Explain that a liberal coating of coupling agent must be applied to the skin so that there is no air between the skin and the transducer and to allow for easy movement of the transducer over the skin. A sensation of warmth or wetness may be felt.

  4. Advise the patient to remove clothing and jewelry from the neck area.

  5. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Posttest Patient Care

  1. Review test results; report and record findings. Modify the nursing care plan as needed.

  2. Counsel about follow-up testing (thyroid nuclear scans) or treatment for thyroid (surgical removal) or neck abnormalities.

  3. Follow guidelines in Chapter 1 for safe, effective, informed posttest care.

Interfering Factors ⬆ ⬇

  1. Nodules <1 cm in diameter may escape detection.

  2. Cysts not originating in the thyroid may show the same ultrasound characteristics as thyroid cysts.

  3. Lesions >4 cm in diameter frequently contain areas of cystic or hemorrhagic degeneration and give a mixed echogram that is difficult to correlate with specific disease.

Reference Values ⬆

Normal