^99Tc^m—MIBISPECT结合定位CT显像诊断功能亢进异位甲状旁腺的价值

目的评价^99Tc^m-甲氧基异丁基异腈（MIBI）SPECT结合定位CT显像对功能亢进异位甲状旁腺的定位诊断价值。方法回顾性分析28例功能亢进异位甲状旁腺患者的手术、病理及影像资料。28例均行常规CT检查，其中25例先行双时相^99Tc^m-MIBI显像，对甲状腺外存在异常放射性浓聚灶患者，随即进行SPECT结合定位CT采集，经计算机处理得到二者融合图像，对放射性浓聚灶进行精确定位。以手术及病理检查结果为检查“金标准”，所有患者均按4个甲状旁腺计算，经手术及病理检查证实的为阳性，其余判为阴性。CT检查与核医学显像结果的比较采用四格表，检验。结果手术中28例患者共摘除28个异位病灶，均为单发。病理检查结果均为腺瘤。28例患者常规CT检查共发现22个阳性病灶，其中真阳性17个，假阳性5个，另假阴性11个，真阴性79个；25例^99Tc^m-MIBISPECT结合定位CT显像发现阳性病灶23个，无假阳性，另假阴性2个，真阴性75个。常规CT检查与核医学显像对检出病理性甲状旁腺的灵敏度分别为61％（17／28）、92％（23／25），特异性为94％（79／84）、100％（75／75），准确性为86％（96／112）、98％（98／100），阳性预测值为77％（17／22）、100％（23／23），阴性预测值为88％（79／90）、97％（75／77）；两者间比较差异有统计学意义，灵敏度：χ^2=6．98，P〈0．01，特异性：χ^2=4．61，P〈0．05，准确性：χ^2=10．30，P〈0．01，阳性预测值：χ^2=5．88，P〈0．05，阴性预测值：χ^2=5．36，P〈0．05。结论^99Tc^m—MIBI SPECT结合定位CT显像对功能亢进异位甲状旁腺的定位诊断优于常规CT，但存在一定的假阴性。

Diagnosis of hyperfunctioning ectopic parathyroid glands using ~(99)Tc~m-MIBI SPECT scintigraphy combined localizable CT

Objective To evaluate the diagnostic value of ~(99)Tc~m-methoxyisobutylisonitrile (MIBI) SPECT scintigraphy combined Iocalizable CT in the localization of ectopic parathyroid glands in hyperparathyroidism.Methods Retrospective data of surgery,pathology and imaging were collected from 28 patients with hyperfunctioning ectopic parathyroid glands.All cases underwent CT studies.Twenty-five patients had ~(99)Tc~m-MIBI planar imaging first:SPECT scintigraphy combined localizable CT was performed for the patients with abnormal radionuclide foci immediately.The fusion images obtained after reconstruction showed the exact location of the ectopic foci.Operative histopathologic results were regarded as "gold standards".Presuming 4 parathyroid glands as normal findings,findings confirmed by operation and pathology were regarded as positive,otherwise negative.The results of CT and radionuclide imaging were compared by X~2-test of four-foId table.Results Twenty-eight ectopic parathyroid glands were found in 28 patients,all pathologically confirmed as adenomss.CT found 22 foci,of which 17 were true positive,5 false positive,11 false negative,and 79 true negative.~(99)Tc~m-MIBI SPECT scintigraphy combined localizable CT found 23 foci,no false positive,2 false negative,and 75 true negative.The results showed that the sensitivities were 61% (17/28),92%(23/25),specificities 94%(79/84),100%(75/75),accuracies 86%(96/112),98% (98/100),positive predictive values 77%(17/22),100%(23/23),and negative predictive values 88% (79190),97%(75/77),respectively,for CT and radionuclide imaging.~(99)Tc~m-MIBI SPECT scintigraphy combined localizable CT was therefore significantly higher than CT in sensitivity(X~2=6.98,P＜0.01),specificity (X~2=4.61,P＜0.05),accuracy (X~2=10.30,P＜0.01),positive predictive value(X~2=5.88,P＜0.05) and negative predictive value (X~2=5.36,P＜0.05).Conclusion ~(99)Tc~m-MIBI SPECT scintigraphy combined localizable CT is superior to CT alone in the localization of ectopic parathyroid glands in hyperparathyroidism,but false negative can be found in some patients.