Objective To study the value of ⁹⁹Tc^m-MIBI dynamic blood flow perfusion imaging and double-phase radionuclide imaging in benign and malignant cold thyroid nodules.

Methods Retrospective analysis of surgical treatment of cold thyroid nodules of 28 patients. Use dual-head SPECT with low energy and high resolution collimator to get dynamic ⁹⁹Tc^m-MIBI blood flow perfusion imaging, 30 min early-phase and 120 min delayed-phase static planar imaging. The images are comprehensive analysed by T/NT and other methods.

Results Nine cases of thyroid cancer in the dynamic blood flow perfusion, 30 min early-phase and 120 min delayed-phase static planar imaging, contain positive imaging 5, 6 and 7 cases respectively. 19 cases of benign lesions contain negative imaging 14, 11 and16 cases respectively. Sensitivity of ⁹⁹Tc^m-MIBI dynamic perfusion imaging in the diagnosis of thyroid cancer is 55.56%, specificity is 73.68%, accuracy is 67.85%. Sensitivity of 30 min early-phase static planar in the diagnosis of thyroid cancer is 66.67%, speci-ficity is 57.89%, accuracy is 67.85%. Sensitivity of 120 min delayed-phase static planar imaging in the diagnosis of thyroid cancer is 77.78%, specificity is 84.21%, accuracy is 82.14%.

Conclusions ⁹⁹Tc^m-MIBI dual-phase imaging in the diagnosis and differential diagnosis of cold thyroid nodules has some value, comprehensive analysis of the blood perfusion and the T/NT of ⁹⁹Tc^m-MIBI dual-phase imaging can reduce the occurrence of false positive and false negative cases.