MRI及99Tcm-MIBI显像对甲状旁腺机能亢进症的诊断价值

目的：评价MRI及^99Tcm-甲氧基异丁基异腈（MIBI）显像在原发性甲状旁腺机能亢进症（PHT）中检出病理性腺体的临床价值。方法：25例经手术证实的PHT患者实行了术前定位MRI检查，若甲状旁腺部位发现可凝软组织肿物，其信号高于周围正常甲状腺，则认为是病理性甲状旁腺，其中23例同时进行了双时相99Tcm-MIBI显像，如早期相出现放射性浓聚区且延迟相持续存在则考虑为异常甲状旁腺，MRI和99Tcm-MIBI显像阅片结果与病理检查结果对照。结果：术中共发现39个异常甲状旁腺，包括19个腺瘤（18例），19个增生（6例）和1个上皮细胞癌（1例），MRI和99Tcm-MIBI显像对检出病理性腺体的准确性分别为84．1％和85．0％,但前者灵敏度（74．4％）高于后者（67．6％），而后者的特异性（97．8％）高于前者（91．8％），两种方法联合应用准确性提高到91．3％，灵敏度为91．2％，特异性为91．3％，结论：99Tcm-MIBI显像可作为继B超检查之后的首选术前定位检查法，但最理想的最联合应用MIR和99Tcm-MIBI显像。

Diagnosis of hyperparathyroidism with MRI and 99Tcm-MIBI scintigraphy

Objective To evaluate the clinical diagnostic capability of MRI and 99 Tc m-MIBI scintigraphy for detecting abnormal glands in primary hyperparathyroidism (PHT). Methods MRI was performed for preoperative localization in 25 patients with PHT that was confirmed by surgery.Parathyroid glands were considered to be abnormal,when masses appeared in suspected location and showed increased signal intensity comparing with adjacent thyroid on either one of the two sequences(T1W1,T2W1). Of these,23 underwent double-phase 99 Tc m-MIBI scintigraphy.A positive scan was defined as a region of increased focal uptake that persisted on the delayed images.Interpretations for both MRI and 99 Tc m-MIBI scintigraphy were compared with the final pathological diagnosis. Results 39 pathologic parathyroid glands were identified in surgery. There were 19 adenomas in 18 patients,19 hyperplasias in 6 patients and 1 carcinoma in 1 patient. The accuracy for detecting the pathologic gland was 84.1% for MRI and 85.0% for 99 Tc m-MIBI scintigraphy,respectively. The sensitivity of MRI (74.4%) was higher than that of 99 Tc m-MIBI scintigraphy (67.6%),but the specificity was higher for 99 Tc m-MIBI scintigraphy (97.8%) than that for MRI (91.8%). Combination of MRI and 99 Tc m-MIBI scintigraphy improved the accuracy up to 91.3%,with the sensitivity of 91.2% and the specificity of 91.3%. Conclusions 99 Tc m-MIBI scintigraphy should be considered as the first choice for preoperative localization when there is an unclear result on ultrasonography in patients with PHT,but a combination of MRI and 99 Tc m-MIBI scintigraphy will be most sensitive and accurate for detection of abnormal parathyroid glands.