Which imaging modality is most accurate for preoperative localization of a hyperfunctioning parathyroid adenoma?

Which imaging modality is most accurate for preoperative localization of a hyperfunctioning parathyroid adenoma?

• A. Sestamibi scan
• B. CT neck
• C. MRI neck
• D. Ultrasound neck

Answer: (A)

Localizing a hyperfunctioning parathyroid adenoma relies on a functional imaging test that highlights tissue based on its activity. Tc-99m sestamibi is taken up by mitochondria-rich parathyroid cells, and while the thyroid clears the tracer on delayed imaging, the adenoma often remains positive. This delayed retention makes the adenoma stand out and allows precise localization, including glands that are ectopic or in the mediastinum. The accuracy is further enhanced by combining with SPECT/CT, which merges the functional signal with exact anatomy. In comparison, ultrasound is helpful for superficial glands but misses deep or ectopic ones and is highly operator-dependent; CT and MRI provide anatomy but lack the functional contrast to reliably identify the adenoma. So, the sestamibi scan is the most accurate preoperative localization test.

Localizing a hyperfunctioning parathyroid adenoma relies on a functional imaging test that highlights tissue based on its activity. Tc-99m sestamibi is taken up by mitochondria-rich parathyroid cells, and while the thyroid clears the tracer on delayed imaging, the adenoma often remains positive. This delayed retention makes the adenoma stand out and allows precise localization, including glands that are ectopic or in the mediastinum. The accuracy is further enhanced by combining with SPECT/CT, which merges the functional signal with exact anatomy. In comparison, ultrasound is helpful for superficial glands but misses deep or ectopic ones and is highly operator-dependent; CT and MRI provide anatomy but lack the functional contrast to reliably identify the adenoma. So, the sestamibi scan is the most accurate preoperative localization test.