Summary & Overview
CPT 78018: Thyroid Scan, Nuclear Medicine Imaging
CPT code 78018 represents a nuclear medicine thyroid scan that uses a radionuclide to assess thyroid gland function, detect nodules, or, in patients with thyroid cancer, evaluate for metastatic disease. This diagnostic imaging procedure is a key tool in endocrinology and oncology for characterizing thyroid pathology and guiding subsequent clinical management. Nationally, thyroid scans influence diagnostic pathways, imaging utilization, and coordination between imaging centers and referring clinicians.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context and the typical settings where the service is delivered, followed by practical benchmarking information where available. The publication covers common payer considerations, expected sites of service, and how this service fits into broader diagnostic workflows. It also outlines what to expect in claims processing and documentation needs tied to nuclear medicine imaging of the thyroid.
This summary is intended for health policy analysts, coding specialists, and practice managers seeking a national-level briefing on CPT code 78018, its clinical purpose, and payer coverage landscape. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 78018 describes a thyroid scan performed with a radionuclide to evaluate thyroid gland function or to detect thyroid nodules. The examination may include a focused thyroid imaging study or a whole-body thyroid scan in patients with a history of thyroid cancer to evaluate for metastatic spread.
Service type: Nuclear medicine diagnostic imaging
Typical site of service: Hospital outpatient imaging center or freestanding nuclear medicine/imaging facility. Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is a 45–70-year-old adult referred by an endocrinologist for a 78018 thyroid scan due to a palpable thyroid nodule, abnormal thyroid function tests, or staging/follow-up of differentiated thyroid carcinoma. The clinical workflow begins with the referring clinician ordering the nuclear medicine study with clinical indication (for example, evaluation of a hyperfunctioning nodule or post-thyroidectomy whole-body survey after radioactive iodine). The nuclear medicine department verifies pregnancy status and recent contrast or iodine exposure, reviews thyroid-stimulating hormone (TSH) and radioactive iodine uptake indications, and determines appropriate radiopharmaceutical (commonly technetium-99m pertechnetate or I-123). On arrival, the patient is screened, consented for the imaging procedure, and the radiotracer is administered intravenously or orally per protocol. After appropriate uptake time, planar and/or SPECT images of the thyroid (or whole body for metastatic survey) are acquired and reviewed by a nuclear medicine physician. The interpreting physician documents findings, impression, and any comparison to prior studies. The report and images are transmitted to the referring provider for clinical management decisions such as biopsy, surgery, radioiodine therapy, or surveillance.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When reporting only the physician interpretation separate from the technical component provided by the imaging facility. |