Objective To observe the characteristic of ⁹⁹Tc^m-MIBIdouble-phaseimaging, andcompared with the pathologic result to discuss and evaluate the diagnostic and difference diagnostic value of earlyimaging and delayed-imaging to benign and malignant lesion in thyroid.

Methods Eighty-nine pathological proven thyriod lesions patients were included in this study(38 cases of thyroid cancer and 51 cases of thyroid benign lesion).⁹⁹Tc^m-MIBI early-imaging and delayed-imaging of thyroid were performed, and comaratively analyzed the T/NT ratio of early-imaging and delayed-imaging of thyroid cancer and thyroid benign lesion.

Results There was no significance in the T/NT ratio of ⁹⁹Tc^m-MIBI early-imaging between thyroid cancer group(T/NT=1.32±0.03)and thyroid benign lesion group(T/NT=1.26±0.22)(t=0.63, P > 0.05).The T/NT ratio of delayed-imaging was high(T/NT=1.72±0.39)than that of benign lesion(T/NT=1.20±0.36), and there was statistically significance between them(t=3.45, P < 0.05).

Conclusions The sensitivity is high for diagnosing thyroid cancer through ⁹⁹Tc^m-MIBI early-imaging but specify is low, and specify is high for diagnosing thyroid cancer using ⁹⁹Tc^m-MIBI delayed-imaging, which is better for differencing malignancy from benignity in thyroid.