目的 探讨99mTc-甲氧基异丁基异腈(99mTc-sestamibi,99mTc-MIBI)双时相法平面显像及SPECT/CT断层显像对继发性甲状旁腺功能亢进症(secondary hyperparathyroidism, SHPT)临床应用价值，初步探讨SPECT/CT断层显像是否可以提高SHPT术前定位诊断的准确性。 方法 采用99mTc-MIBI双时相法显像。31例患者中22例行平面显像，9例行平面及SPECT/CT断层显像，全部病例均经手术和病理检查证实。将每一患者延迟显像中甲状旁腺摄取的最高放射性比值(T/NT)与其近期全段甲状旁腺激素(intact parathyroid hormone,iPTH)水平及手术和病理结果进行对照。 结果 患者延迟显像中甲状旁腺摄取的最高T/NT值与其显像前iPTH值呈正相关(r=0.426,P＜0.05),与其手术切除的相应甲状旁腺体积呈显著正相关(r = 0.352,P＜0.01)。所有手术切除的甲状旁腺病理结果均为增生。平面显像在经手术和病理检查证实的106枚功能亢进的甲状旁腺中检出了73枚，准确性为68.9%。SPECT/CT断层显像在经手术和病理检查证实的30枚功能亢进的甲状旁腺中检出了23枚，准确性为76.7%，这些患者的平面显像检出了19枚甲状旁腺，准确性为63.3%。SPECT/CT显像对于继发甲旁亢的增生甲状旁腺检出的准确性较高。 结论 99mTc-MIBI双时相显像能够估测甲状旁腺功能及其增生的程度，也是定位诊断SHPT的有效方法。SPECT/CT断层显像较单纯平面显像能发现更多功能增强的甲状旁腺，结合CT断层对于病灶的解剖定位更加准确，尤其是术后继发甲旁亢持续存在或复发需再次手术者，为手术治疗继发甲旁亢提供更多证据。

Objective To discuss the clinical value of dual-phase 99mTc-sestamibi (99mTc-MIBI) scintigraphy and SPECT/CT in secondary hyperparathyroidism, and to investigate the possibility of SPECT/CT for the accurate localization diagnosis of secondary hyperparathyroidism preoperatively. Methods Thirty-one patients underwent parathyroid imaging with double-phase 99mTc-MIBI before surgery for hyperparathyroidism. Planar imaging was conducted in 22 patients, and planar and SPECT/CT imaging in 9 patients. The diagnosis of hyperparathyroidism was confirmed by surgical and pathological findings. Target/non-target (T/NT) ratio in delay image was compared with the volume of excised parathyroid, the intact parathyroid hormone (iPTH), and the pathology of the surgical sample. Results T/NT ratio was correlated with serum iPTH (r=0.426, P<0.05) and parathyroid volume (r=0.352, P<0.01). Hyperplasia of parathyroid gland was found in all excised samples. Planar images showed hyperparathyroidism in 73 of the 106 excised parathyroid glands, and the accuracy rate is 68.9%. In the 30 excised parathyroid glands, SPECT/CT images detected 23 hyperparathyroidism (accuracy rate 76.7%), and planar imaging found 19 hyperparathyroidism (accuracy rate 63.3%). Conclusions Dual-phase 99mTc-MIBI scintigraphy can be used to assess function and hyperplasia of parathyroid, being the most effective method for localization diagnosis of secondary hyperparathyroidism. SPECT/CT imaging is more efficient than planar imaging for the detection of parathyroid glands with hyperparathyroidism. SPECT/CT parathyroid imaging combined with CT scan will provide more information about localization of the lesions, especially for those with persistent or recurrent hyperthyroidism after parathyroidectomy.