产后垂体MRI测量与激素水平变化的研究

Measurment on MRI and Studies on Changes of Hormone Level of Pituitary after Delivery

目的:观察产后垂体形态学变化及其与体内相关激素水平变化的关系。方法:自然分娩的产妇50名,分别于产后7d、3个月、6个月及9个月时行垂体MRI检查及血清激素检查。MRI扫描采用三维破坏性稳态梯度回聚回波(3D-SPGR)序列行垂体3DT1WI扫描。在工作站上测量不同时期垂体体积及信号强度。血清激素检查采用放射免疫分析法测定。结果:垂体的平均体积于产后7d时为(548±44)mm3、3个月时为(526±42)mm3、6个月时为(518±41)mm3、9个月时为(516±41)mm3。垂体前叶与桥脑的相对信号强度在产后7d与3个月时及3个月与6个月时的差异有显著性(P<0·05),而6个月与9个月间比较差异无显著性。血清激素检测:催乳素(PRL)于产后7d水平最高,产后6个月达到非孕期正常范围;促甲状腺激素(TSH)与β-绒毛膜促性腺激素(β-HCG)均于产后7d最高,3个月为正常范围;而雌二醇(E2)在产后7d即在正常范围。结论:产后垂体的体积逐渐减小,前叶信号强度逐渐减低,其形态学变化与相关激素水平的变化具有一定的关联性。

Objective:To explore changes in the volume and signal intensity on T1-weighted magnetic resonance (MR) images of the pituitary gland after delivery and relationship between the changes and hormone levels.Method:50 participants who were natural labor underment MRI examination and clinical biochemistry assessment 7days、 3months、 6months and 9months after delivery respectively.The volume and signal intensity of the pituitary were measured on imaging workstation.Radioimmunoassay method was adopted in the hormone determination.Results:The mean pituitary volume was (548±44) mm3 at 7 days, (526±420mm3 at 3months,(518±41)mm3 at 6 months, and (516±41)mm3 at 9 months after delivery.The mean ratio of the signal intensity of the anterior lobe of the pituitary to the signal intensity of the pons was with significant differences between 7 days and 3 months and between 3 and 6 months after delivery(P<0.05).Serum level of PRL was high after 7 days and then decreased to normal scope after 6 months; Levels of TSH and β-HCG were also high after 7 days and came back to normal range after 3 months;The level of E2 was normal after 7 days.Conclusion:The volume and the T1-weighted signal intensity of the anterior lobe of the pituitary decrease up to 6 months after delivery, and there exists a certain correlation between changes of volume and signal intensity of pituitary and hormone levels.