DCE-MRI血管功能参数在垂体微腺瘤诊断中的应用研究

Diagnostic value of Vascular functionnal parameters in dynamic contrast-enhanced MRI for pituitary microadenomas

目的探讨动态增强磁共振(DCE-MRI)血管功能参数在垂体微腺瘤诊断中的价值。方法回顾性分析经临床表现、实验室检查、MRI检查及诊断性治疗证实的34例泌乳素微腺瘤患者、24例单纯泌乳素升高患者及20例健康人的DCE-MRI图像,获得垂体及微腺瘤微血管渗透性定量参数及半定量参数(容量转移常数K^(trans)、Ve、速率常数K_(ep)、达峰时间TTP)。采用t检验分析微腺瘤与邻近正常腺垂体组织各参数值的差异;采用方差分析对比微腺瘤组、单纯泌乳素升高组、健康对照组之间及健康对照组腺垂体左侧、中间、右侧之间各参数之间的差异;两两比较采用最小显著差异法;通过ROC曲线对各参数诊断微腺瘤的敏感度及特异度进行分析。P<0.05为差异具有统计学意义。结果 1)垂体中间部位TTP值小于左侧及右侧,差异具有统计学意义;2)微腺瘤较邻近正常腺垂体组织的K^(trans)、K_(ep)值降低,TTP值升高,差异具有统计学意义;3)微腺瘤组较单纯泌乳素升高组及健康对照组的K^(trans)、K_(ep)值降低,TTP值升高,差异具有统计学意义。而单纯泌乳素升高组较健康对照组的K^(trans)、K_(ep)、TTP值差异无统计学意义;4)对微腺瘤的诊断,参数K^(trans)、K_(ep)诊断效能均高于TTP。K^(trans)-K_(ep)联合诊断的诊断效能高于K^(trans)-TTP及TTP-K_(ep)联合。K^(trans)-K_(ep)-TTP三者联合诊断效能最高。结论DCE-MRI功能参数可反映垂体微腺瘤的微血管变化,定量参数K_(ep)对微腺瘤的诊断效能较高,多参数联合有助于进一步提高垂体微腺瘤的诊断水平。

Objective To investigate quantitatively microvascular parameters in pituitary microadenomas by dynamic contrast- enhanced magnetic resonance imaging （DCE-MRI）. Methods MRI date was analyzed in 20 normal female adenohypophysis, 24 patients with hyperprolactinemia and 34 patients with pituitary hyperprolactinemia microadenomas conformed with clinical, labora- tory examination or diagnostic treatment retrospectively. The microvascular function parameters of pituitary gland （ volume transfer constant, Ktrans; extravavasctdar extracelluar volume fraction, Ve; rate constant, Kep ; time to peak, TTP） were obtained. A t test was used to compare the difference of parameters between microadenomas and its surrounding pituitary tissue. Analysis of variance （ANOVA） was used to evaluate the difference of parameters among these three groups and the difference of parameters of left, median and right pituitary gland in control group. Least significant difference （LSD） was used for pairwise comparison. The sensi- tivity and specificity of each parameter in diagnosing pituitary microadenomas were analyzed by ROC curve. A P value of ≤0.05 was considered significant. Results 1 ） TIP value was significantly lower in media pituitary gland than that in left and right pitui- tary gland ; 2） Ktrans and Kep value of pituitary microadenomas were significantly lower and TrP value of pituitary microadenomas was significantly higher than those of their surrounding tissue respectively; 3 ） Ktrans and Kep value were significantly lower and TIP value was significantly higher in microadenomas group than those in both hyperprolactinemia and control group. There was no sig- nificant difference in Ktrans, Kep and TIP between hyperprolactinemia and control group; 4） The diagnostic efficacy of Ktrans and Kep was significantly higher than that of TTP for micro-adenomas. The diagnostic efficacy of the combined use ofKtrans- Kep was sig- nificantly higher than that of the combined use of Ktrans- TIP, and TIP and Kep, respectively. The diagnostic efficacy of the com- bined use of Ktrans-Kep-TTP was the highest for microadenomas. Conclusion The vascular functionnal parameters in DCE-MRI could quantitatively analyze the microvascular change of pituitary microadenomas, parameter Kep show higher diagnostic efficacyand the combined use of multi-parameters is helped to improve the diagnosis of pituitary microadenomas.