Fig. 1

Representative ^99mTc-MIBI thyroid images indicative of hyperparathyroidism. The patient was intravenously injected with 740–925 MBq^99mTc-MIBI. A single-photon emission (SPECT)/CT instrument was used, which was equipped with a parallel low-energy high-resolution collimator with an energy peak of 140 keV and a window width of 20%. The magnification when performing the neck scan was 1.5-fold, with a matrix of 128 × 128 pixels and an acquisition count of 1000 K at 10 min and an acquisition count of 682 K at 120 min ^99mTc-MIBI injection. Two points have the same acquisition time of 600 s. Neck systemic planar images were obtained after 10 min a and 120 min b; c-e There is a soft tissue nodule located in the posterior lobe of the left thyroid gland, with radioactive accumulation