Comparison between technetium-99m methoxyisobutylisonitrile scintigraphy and ultrasound in the diagnosis of parathyroid adenoma and parathyroid hyperplasia

Objective The aim of this study was to evaluate the value of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) imaging and ultrasound in preoperative localization of parathyroid adenoma (PA) and parathyroid hyperplasia (PH). Participants and methods A retrospective study of 99mTc-MIBI double-phase scintigraphy (DPS) was performed in 187 hyperparathyroidism cases with pathologically diagnosed PA or PH. Of these patients, 167 cases underwent ultrasound, and 146 cases underwent 99mTc-MIBI single-photon emission computed tomography/computed tomography (SPECT/CT). The sensitivity and diagnostic accuracy of ultrasound, 99mTc-MIBI DPS, and SPECT/CT were compared between PA and PH. Differences in 99mTc-MIBI DPS, serum parathyroid hormone (PTH), serum calcium and phosphorus, as well as the weight and longest diameter of lesion between PA and PH were also compared. Results As per patient-based analysis, the sensitivity of ultrasound, 99mTc-MIBI DPS, and SPECT/CT was 90.70% (39/43), 95.56% (43/45), and 100.00% (30/30), respectively, for PA, and 93.55% (116/124), 90.85% (129/142), and 93.10% (108/116), respectively, for PH. There were no significant differences in sensitivity of these three imaging methods between PA and PH. However, per lesion-based analysis, the accuracy of ultrasound, 99mTc-MIBI DPS, and SPECT/CT in detecting PA was 78.43% (40/51), 86.79% (46/53) and 96.88% (31/32), respectively, and the accuracy of 99mTc-MIBI DPS was higher than that of ultrasound (χ2=6.507, P=0.011), and for PH, it was 49.69% (160/322), 40.71% (171/420), and 43.80% (152/347), respectively. The accuracy of ultrasound was higher than that of 99mTc-MIBI DPS (χ2=5.940, P=0.015). The accuracy of a combination of all three examinations of ultrasound+99mTc-MIBI DPS, ultrasound+99mTc-MIBI SPECT/CT, 99mTc-MIBI DPS+SPECT/CT, and ultrasound+99mTc-MIBI DPS+99mTc-MIBI SPECT/CT was 51.51% (154/299), 53.85% (161/299), 50.17% (150/299), and 54.18% (162/299), respectively, which was higher than that of ultrasound (χ2=5.273, P=0.022; χ2=8.226, P=0.004; χ2=3.880, P=0.049; χ2=8.702, P=0.003, respectively). Serum levels of PTH and phosphorus were lower in patients with PA than in patients with PH (P