Detection and Localization of Parathyroid Adenomas in Patientswith Hyperparathyroidism Using a Single Radionucide ImagingProcedure

Dualradionuclideimagingusing a com@nafionof @°1Tl with either 99mTc0401'1231 is recognizedas a useful procedure in the preoperative localization of parathyroid adenomas. Re cently, @rc-sestamibl (MIBI)has been introduced for myo cardial perfusion imaging as an alternative to @°i1. The pur pose of this prospective study was to evaluate pa.rathyroid scan using early and late imaging following MIBI injection. Twenty-three patients (21 F, 2 M, mean age: 57 yr) with a dinical and biologicdiagnosis of hyperparathyroidismwere submitted to a MIBIstudy prior to surgical exploration of the neck. Cervico-thoraacplanar imaging(anteriorview, 10 min/ view) was performed at 15 mm and at 2—3hr after an intravenousinjectionof 20—25 mCiof MIBI.A positive MIBI scan for parathyroid adenoma was defined as an area of increased focal uptake which persisted on late imaging, con trary to the uptake in the normal thyroid tissue which pro gressivelydecreases over time(differential washout).Surgical exploration of the neck, performed between 1 day and 72 days (average: I 6 days) after the MIBIstudy, showed a parathyroidadenoma in 21 patients and hyperplasia in two patients. MIBIscan correctly detected and localized 19/21 adenomas (90%).In conclusion,parathyroidimagingusing a singleradionuclidewith MIBI(earlyand late study withdiffer ential washout analysis) is a promising procedure in the preoperative detection and localization of parathyroid adeno mas in patients withprimaryhyperparathyroidism. JNucIMed 1992;33:1801—1807