CG12FZZ
Planar Nuclear Medicine Imaging Thyroid Gland to None with None, Iodine 123 (I-123) Approach
Procedural Specifications
| Clinical Axis | Detail Definition |
|---|---|
| Section | C Nuclear Medicine |
| Body System | G Endocrine System |
| Operation | 1 Planar Nuclear Medicine Imaging |
| Body Part | 2 Thyroid Gland |
| Approach | F Iodine 123 (I-123) |
| Device | Z None |
| Qualifier | Z None |
Operation Definition
Introduction of radioactive materials into the body for single plane display of images developed from the capture of radioactive emissions
Procedure Overview
This family describes single-plane radioactive imaging of endocrine glands, most often a thyroid scan and sometimes a parathyroid or adrenal scan. A small amount of radioactive iodine or technetium pertechnetate is swallowed or injected, the gland absorbs it in proportion to how active its cells are, and a gamma camera held in one or two fixed positions captures flat, two-dimensional pictures of the uptake pattern.
Physicians use this scan to tell apart different causes of an overactive thyroid, such as Graves' disease versus a single toxic nodule, to characterize a thyroid nodule found on ultrasound, or to look for residual or recurrent thyroid cancer tissue after surgery. A parathyroid version, usually done with a sestamibi tracer, helps locate an overactive parathyroid gland before surgery. The scan is painless and usually completed within an hour of the tracer being given, though thyroid studies sometimes require the patient to return for delayed images.
Anatomy & Axis Detail
Thyroid Gland
As a butterfly-shaped gland straddling the trachea in the anterior neck, the thyroid concentrates iodine and iodine-like tracers such as technetium-99m pertechnetate through active transport, a property that makes planar imaging a direct window into follicular cell function and regional activity across the gland. The resulting images characterize nodules as hot, warm, or cold relative to surrounding tissue, a distinction that carries different implications for malignancy risk, and can reveal diffuse hyperfunction in conditions like Graves disease or patchy uptake in multinodular goiter. Because the gland's two lobes and isthmus are relatively superficial and fixed in position, anterior planar views alone are usually sufficient, with pinhole collimation sometimes used to improve resolution of individual nodules within the gland.
Radionuclide: Iodine 123 (I-123)
Iodine 123 (I-123) marks nuclear medicine studies using this radionuclide, typically for thyroid uptake and scanning studies or certain neurologic imaging, owing to its favorable gamma emission and shorter half-life compared to Iodine 131. It differs from I-131, which is used both diagnostically and therapeutically at higher doses, and from Tc-99m, which serves a broader range of general imaging indications.
Coding & Documentation
Coding from this family depends on documentation showing that only flat, single-position images were acquired, without a rotational SPECT component. The report should identify the tracer, the gland imaged, and the camera views obtained. A frequent mistake is applying this code when the department actually performed a combined uptake-and-scan visit; the uptake measurement and the imaging are distinct root operations and both must be captured if both were done. Another recurring error is defaulting to "planar" because that is the more familiar term, when the technologist's protocol notes actually describe a SPECT acquisition.
Commonly Confused With
The closest look-alike is Tomographic Nuclear Medicine Imaging of the endocrine system, which differs only in whether the camera rotated to produce 3D reconstructions; dual-phase parathyroid protocols in particular are frequently planar-only despite reports that use the word "tomographic" loosely. It is also confused with Nonimaging Nuclear Medicine Uptake, which measures gland function as a percentage or count rate and produces no picture at all.