This study was designed to evaluate the ability of PET/MRI, using ¹⁸F-FDG and ⁶⁸Ga-DOTATATE as tracers, to detect hormone-producing pituitary microadenoma when diagnosis is difficult using MRI alone. Methods: We recruited 37 patients with elevated hormone levels, including 19 with undiagnosable primary pituitary adenoma and 18 with suspected recurrent pituitary adenoma. ¹⁸F-FDG PET/MRI and ⁶⁸Ga-DOTATATE PET/MRI were performed within 1 wk of each other in all patients. Within 2 wk afterward, 27 of the 37 patients underwent transsphenoidal adenomectomy, 3 underwent sella region radiotherapy, 1 underwent somatostatin therapy, and 6 had only clinical follow-up. The image characteristics and uptake levels were correlated with the surgical findings and pathologic results. Receiver-operating-characteristic curves were analyzed to determine the optimal cutoff to differentiate adenoma from normal pituitary tissue. The area under the receiver-operating-characteristic curve was calculated to compare diagnostic performance. Results: The PET/MR images were of diagnostic quality and without obvious image artifacts. The high contrast of the PET images provided complementary information to the fine anatomic display of the MR images. Increased ¹⁸F-FDG uptake was clearly observed in all patients. MRI enhanced using a 0.05 mmol/kg dose of gadopentetate dimeglumine showed suggestive findings in only 47% of the patients with primary adenoma and 39% of those with recurrent adenoma; when a 0.1 mmol/kg dose was used, the respective percentages were 37% and 50%. The ¹⁸F-FDG SUV_max of the 16 primary adenomas that underwent transsphenoidal adenomectomy (6.8 ± 3.7) was significantly higher than that of normal pituitary tissue (3.2 ± 1.1, P < 0.01). The adenomas showed moderate ⁶⁸Ga-DOTATATE uptake (SUV_max, 3.8 ± 2.6), but the ⁶⁸Ga-DOTATATE uptake was generally lower than that of normal pituitary tissue (SUV_max, 6.2 ± 3.2, P < 0.05). In the 11 suspected recurrent pituitary adenomas that underwent transsphenoidal adenomectomy, the ¹⁸F-FDG SUV_max was 6.1 ± 3.5, significantly higher than that of normal pituitary tissue (2.5 ± 1.1, P < 0.01), and the ⁶⁸Ga-DOTATATE SUV_max was 3.0 ± 1.1, significantly lower than that of normal pituitary tissue (5.5 ± 1.7, P < 0.01). The ¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_max ratio of the adenomas (2.3 ± 1.5) was significantly higher than that of normal pituitary tissue (0.6 ± 0.3, P < 0.05). When the ¹⁸F-FDG SUV_max alone and the ¹⁸F-FDG/⁶⁸Ga-DOTATATE SUV_max ratio were used as criteria to discriminate between adenoma and pituitary tissue, the best analysis came from the ratio, and that from ¹⁸F-FDG SUV_max alone was slightly less, with optimal diagnostic cutoffs of 1.04 and 3.88, respectively. Conclusion: PET/MRI provides an ideal tool for the detection of hormone-producing pituitary microadenoma. Dual-tracer ¹⁸F-FDG and ⁶⁸Ga-DOTATATE PET/MRI was useful for distinguishing pituitary microadenoma from normal pituitary tissue.

这项研究旨在评估PET / MRI的能力，使用¹⁸ F-FDG和⁶⁸ Ga-DOTATATE作为示踪剂，当仅凭MRI难以诊断时，可检测产生激素的垂体微腺瘤。方法：我们招募了37例激素水平升高的患者，其中19例患有不可诊断的原发性垂体腺瘤，18例疑似复发性垂体腺瘤。¹⁸ F-FDG PET / MRI和⁶⁸在所有患者中，彼此间隔1周内进行了Ga-DOTATATE PET / MRI。之后的2周内，在37例患者中，有27例接受了经蝶窦切除术，3例接受蝶鞍区放疗，1例接受了生长抑素治疗，6例仅接受了临床随访。图像特征和摄取水平与手术结果和病理结果相关。分析了接收者的操作特征曲线，以确定区分正常腺垂体腺瘤的最佳临界值。计算接收器工作特性曲线下的面积以比较诊断性能。结果：PET / MR图像具有诊断质量，并且没有明显的图像伪影。PET图像的高对比度为MR图像的精细解剖显示提供了补充信息。在所有患者中均清楚地观察到¹⁸ F-FDG摄取增加。使用0.05 mmol / kg剂量的ado戊二酸二聚丁二胺增强的MRI仅在47％的原发性腺瘤患者和39％的复发性腺瘤患者中显示出提示性发现；当使用0.1mmol / kg剂量时，各自的百分比为37％和50％。经蝶窦切除术的16例原发性腺瘤的¹⁸ F-FDG SUV _max（6.8±3.7）显着高于正常垂体组织（3.2±1.1，P <0.01）。腺瘤表现出中等的⁶⁸ Ga-DOTATATE摄取（SUV _max，3.8±2.6），但⁶⁸ Ga-DOTATATE摄取通常低于正常垂体组织（SUV _max，6.2±3.2，P < 0.05）。在经蝶窦切除术的11例疑似垂体腺瘤复发中，¹⁸ F-FDG SUV _max为6.1±3.5，显着高于正常垂体组织（2.5±1.1，P <0.01）和⁶⁸ Ga-DOTATATE SUV _max为3.0±1.1，显着低于正常垂体组织（5.5±1.7，P <0.01）。在¹⁸腺瘤的F-FDG / ⁶⁸ Ga-DOTATATE SUV_最大比率（2.3±1.5）显着高于正常垂体组织的比率（0.6±0.3，P <0.05）。当单独使用¹⁸ F-FDG SUV _max和¹⁸ F-FDG / ⁶⁸ Ga-DOTATATE SUV _max比率作为区分腺瘤和垂体组织的标准时，最佳分析来自比率，而¹⁸ F-FDG单独的SUV _max略少一些，最佳诊断阈值分别为1.04和3.88。结论：PET / MRI为检测产生激素的垂体微腺瘤提供了理想的工具。双示踪剂¹⁸ F-FDG和⁶⁸ Ga-DOTATATE PET / MRI可用于区分垂体微腺瘤和正常垂体组织。