MIBI-Tc99m + Iodine-123

MIBI-Tc99m + Iodine-123 is a dual-radiotracer combination used in nuclear medicine imaging, particularly for the localization of parathyroid adenomas and evaluation of thyroid and parathyroid disorders. The combination consists of technetium-99m sestamibi (MIBI), a lipophilic radiopharmaceutical that accumulates in mitochondria-rich tissues such as parathyroid adenomas, and iodine-123, a radioisotope selectively taken up by thyroid tissue. This dual-tracer protocol enables precise differentiation between thyroid and parathyroid tissue through image subtraction techniques. MIBI-Tc99m is primarily used for its high sensitivity in detecting hyperfunctioning parathyroid glands, while iodine-123 provides detailed mapping of the thyroid gland. The combined use improves diagnostic accuracy by allowing visual comparison or subtraction imaging to localize abnormal glands even in complex anatomical situations[8][10]. Mechanistically, Tc99m-sestamibi acts as a passive mitochondrial membrane potential agent accumulating preferentially in overactive or abnormal tissues with increased mitochondrial content; iodine-123 is actively transported into thyroid follicular cells via the sodium/iodide symporter.

Other names

MIBI-Tc99m/Iodine-123Tc-99m sestamibi + I-12399mTc-MIBI + I-123