Scanning of the adrenal glands is a nuclear study performed to assist in diagnosing pathology based on the secretory function of the adrenal cortex. This function is controlled primarily by the anterior pituitary through the adrenocorticotropic hormone that stimulates the adrenal cortex to produce cortisone as well as to secrete aldosterone. High concentrations of cholesterol, the precursor in the synthesis of adrenocorticosteroids including aldosterone, are stored in the adrenal cortex. This storage allows the radiopharmaceutical norcholestenol iodomethyl I 131 to be used in identifying pathology. The uptake of this substance occurs gradually and imaging reveals increased uptake, unilateral or bilateral uptake, or absence of uptake in the detection of pathological processes. Suppression studies can be performed to differentiate the presence of a tumor from hyperplasia of the glands, followed by prescanning treatment with corticosteroids.²⁵

• Normal bilateral secretory function of the adrenal cortex with the uptake of the radionuclide; no tumors, infection, or secretory suppression

• Inability of client to remain still during the procedure

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Indications

• Diagnosing Cushing's syndrome revealed by increased symmetrical uptake, indicating bilateral hyperplasia, or asymmetric uptake, indicating unilateral hyperplasia or adenoma
• Determining aldosteronism revealed by asymmetric uptake
• Differentiating between asymmetric hyperplasia and asymmetry from aldosteronism with dexamethasone suppression test
• Determining adrenal suppressibility with prescan administration of corticosteroid to diagnose and localize adrenal adenoma, aldosteronomas, androgen excess, or low-renin hypertension
• Diagnosing glandular tissue destruction caused by infection, infarction, neoplasm, or suppression

Contraindications

• Pregnancy, unless the benefits of performing the procedure greatly outweigh the risks to the fetus

[Section Outline]

• Indications
• Contraindications

Nursing Care Before the Procedure

Client teaching and physical preparation are the same as for any nuclear scan study (see section under "Brain Scanning").

• Inform the client that there will be a prolonged scanning schedule over a period of days and that the time to complete each scan is 30 minutes.
• Administer supersaturated potassium iodide (SSKI) 24 hours before the study to prevent thyroid uptake of the free iodine.
• Obtain a history to include information about the endocrine system, allergy to iodine, laboratory results for cortisol, and urinary adrenal function tests.

The client is placed on the examining table in a supine or sitting position. The radiopharmaceutical is injected IV and the client is returned to the hospital room or requested to return to the department in 24 hours, when the scanning procedure will begin. The client is requested to remain very still in the prone position and the imaging then takes place for posterior views for at least 20 minutes. Scanning is then performed each day for 3 to 5 days after this first scan. If a suppression test is to be performed, 4 mg of dexamethasone is administered for 7 days before the scanning procedure.

Nursing Care After the Procedure

Care and assessment after the procedure are the same as for any nuclear scan study (see section under "Brain Scanning").

• Administer supersaturated potassium iodide 10 days after the injection of the radiopharmaceutical to ensure that the iodine is not taken up by the thyroid gland until the material is entirely excreted.