DCE-MRI定量灌注参数鉴别直肠癌区域淋巴结良恶性的初步探讨  

Discrimination between Metastatic and Non-metastatic Regional Lymph Nodes in Rectal Cancer Using Quantitative Dynamic Contrast-enhanced Parameters

作　　者：杨心悦[1] 陈琰 肖晓娟[2] 杨艳红[1] 文自强 卢宝兰 余深平[1] 

机构地区：[1]中山大学附属第一医院放射科,广东广州510080 [2]北京大学深圳医院放射科,广东深圳518036

出　　处：《中山大学学报（医学科学版）》2017年第6期909-915,共7页Journal of Sun Yat-Sen University:Medical Sciences

基　　金：广东省科技计划项目(2014A020212126)

摘　　要：【目的】采用DCE-MRI定量灌注参数评价直肠癌区域淋巴结,以探究各参数鉴别良恶性淋巴结的临床应用价值。【方法】收集本院2015年1月至2016年8月行术前DCE-MRI扫描且未经新辅助治疗行直肠癌根治术患者122例,纳入术前DCE-MRI与术后病理相对应淋巴结203枚(阳性95枚,阴性108枚),测量各淋巴结短径(S)、长径(L)并计算二者比值(S/L),测算各淋巴结定量灌注参数,包括对比剂容积转换常数(Ktrans)、速率常数(Kep)、单位体积组织细胞外血管外间隙容量(Ve)。比较分析良恶性淋巴结各相关参数,并以S=5 mm为界值,进一步分组比较不同短径下良恶性淋巴结各定量灌注参数;绘制相关定量灌注参数的ROC曲线,获取诊断界值。【结果】转移淋巴结的短径(S)及长径(L)高于非转移淋巴结(P<0.01),S/L及Ktrans、Kep则低于非转移淋巴结(P<0.01),而两组间Ve无统计学差异(P=0.308),Ktrans鉴别良恶性淋巴结的诊断界值(曲线下面积,敏感度,特异度)为0.088 min-1(0.69,58.3%,78.9%)。分组分析显示,当S≥5 mm时,转移淋巴结Ktrans、Kep低于非转移淋巴结(P<0.001),Ve则高于非转移淋巴结(P=0.039),Ktrans鉴别二者的诊断界值(曲线下面积,敏感度,特异度)为0.088 min-1(0.675,57.1%,77.9%);当S<5 mm时,转移淋巴结Ktrans低于非转移淋巴结(P=0.001),其诊断界值(曲线下面积,敏感度,特异度)为0.087 min-1(0.732,60.5%,81.5%),而两组间Kep、Ve则无统计学差异(P>0.10)。【结论】DCE-MRI定量灌注参数Ktrans可用于鉴别直肠癌区域淋巴结的良恶性,且Ktrans在鉴别短径较小(S<5 mm)的淋巴结方面具有一定优势。【Objective】To investigate the diagnostic value of quantitative perfusion parameters of dynamic contrast-enhanced imaging for discriminating metastatic from non-metastatic regional lymph nodes in rectal cancer.【Methods】122 patients of our department were collected from 2015.01 to 2016.08, and 203 lymph nodes, including metastatic lymph nodes(MLNs, n=95) and non-metastatic lymph nodes(NMLNs, n=108), were analyzed. The short-axis diameter(S), long-axis diameter(L), short-to long-axis diameter ratio(S/L), volume transfer constant(Ktrans), rate constant(Kep) and extravascular extracellular space(EES) fractional volume(Ve) were compared between two groups respectively. Then using S=5 mm as a cutoff value, these parameters were compared between subgroups.Receive operating characteristic curve(ROC) was used to analyze the diagnostic efficiency and find the optimal cutoff values.【Results】The metastatic group exhibited higher S and L, but lower S/L, Ktrans and Kep than the non-metastatic group(P<0.01). However,the Ve did not differ significantly between two groups(P=0.308). Optimal cutoff values [area under the curve(AUC), sensitivity, specificity] of Ktrans for discriminate metastatic lymph nodes from non-metastatic were 0.088 min-1(0.69, 58.3%, 78.9%). When S>/=5 mm,subgroup analysis revealed that Ktrans and Kep of MLNs were significant higher than those of NMLNs(P<0.001), but Ve was lower(P=0.039). Optimal cutoff values(AUC, sensitivity, specificity) of Ktrans were 0.088 min-1(0.675, 57.1%, 77.9%). However, when S<5 mm,MLNs showed lower Ktrans than NMLNs(P=0.001), but there were no significantly statistic differences of Kep and Ve between these two groups(P>0.1). Optimal cutoff values(AUC, sensitivity, specificity) of Ktrans were 0.087 min-1(0.732, 60.5%, 81.5%).【Conclusion】Ktranscan be used to discriminate regional MLNs from NMLNs in rectal cancer, especially when the short-axis diameter is less than 5 millimeters.

关 键 词：直肠癌 淋巴结 磁共振灌注成像 微血管灌注 

分 类 号：R445.2[医药卫生—影像医学与核医学]