Parathyroid scintigraphy is a specialised diagnostic imaging procedure used primarily to localise overactive parathyroid glands. The procedure is non-invasive.

The test involves the intravenous administration of a small amount of a radioactive tracer called MIBI. This tracer binds to the parathyroid adenoma and hyperplasia, as well as to the thyroid gland. An early SPECT/CT scan of the patient’s neck and chest is performed to detect ectopic parathyroid adenomas and predict their location very accurately. After the scan, an additional cervical planar image is taken and pertechnetate, another radiopharmaceutical, is injected and another cervical planar image is taken in the same position. The MIBI image shows both the thyroid and the parathyroid, but the pertechnetate image shows only the thyroid, so if we subtract the pertechnetate from the MIBI image, the remaining image shows only the parathyroid adenoma.

In conclusion, MIBI parathyroid scintigraphy with pertechnetate extraction is an effective tool for localising an overactive parathyroid gland and provides the surgical team with a valuable reference point for performing a quick and efficient intervention.