Preoperative localization of parathyroid adenomas using 99mTc-MIBI scintigraphy in patients with hyperparathyroidism.

Background: Technetium (Tc)99m methoxyisobutyl isonitrile (99mTc-MIBI) has recently been introduced for parathyroid imaging, as well as for myocardial imaging. We studied the usefulness of 99mTc-MIBI scintigraphy for preoperative localization of abnormal parathyroid glands.

Methods: The usefulness of 99mTc-MIBI scintigraphy for detection of hyperfunctional parathyroid lesions was evaluated in 5 patients with primary hyperparathyroidism. The results of localizing the abnormal glands by using 99mTc-MIBI were compared with those obtained by using thallium (Tl) 201-technetium (Tc) 99m (201Tl-99mTc) subtraction scintigraphy, computed tomography, and ultrasonography.

Results: The delayed (2 hours) imaging of 99mTc-MIBI scintigraphy was highly useful for accurate localization of the abnormal parathyroid lesions. The diseased glands were detected in all cases where 99mTc-MIBI scintigraphy was used, and using 99mTc-MIBI scintigraphy provided more information than did computed tomography, ultrasonography, or 201Tl-99mTc subtraction scintigraphy.

Conclusions: This method is simple and essential for detecting hyperfunctioning parathyroid glands, especially those with small or ectopic lesions. This technique should be widely applied as a localizing diagnostic method for hyperparathyroidism.