PREOPERATIVE PARATHYROID IMAGING WITH TC- 99M MIBI IODINE-123 SCAN/

Objective: Assess the sensitivity of MIBI-Tc for the detection of para thyroid lesions and define? the threshold of detection by evaluating c ontrast uptake at 20 minutes and 2 hours. Methods: Fifty-five operated and cured patients were studied, Image acquisitions were made 20 minu tes and 2 hours after injection of 555 MBq MIBI-Tc then 2 hours after injection of 5.55 MBq iodine 123. Results: A total of 87 pathological glands were found including 47 adenomas (80 to 8820 mg) and 40 hyperpl asias (44 to 2175 mg), Detection sensitivity was 81% for adenomas and 30% for hyperplasia, but the cell type did not appear to be a determin ing factor. Conclusion: Scintigraphic visualization of parathyroid les ions is more frequent when there is a single lesion, At least one lesi on was seen in 80% of the patients, The threshold of detection was 225 mg, Enhancement of parathyroid uptake with MIBI-Tc compared with the thyroid between 20 minutes and 2 hours was not a constant and of unkno wn origin.