高分辨率磁共振和动态对比增强磁共振在直肠癌T分期中的价值研究

Value of high-resolution magnetic resonance imaging and dynamic contrast-enhanced magnetic resonance imaging in T staging of rectal cancer

目的:探讨高分辨率磁共振(HR-MRI)和动态对比增强磁共振(DCE-MRI)在直肠癌术前诊断和病理T分期中的临床意义及价值。方法:选择2017年3月至2018年2月皖南医学院弋矶山医院收治的直肠癌患者70例为研究对象。在手术前均使用GE公司的3.0T MR扫描仪进行HR-MRI扫描,以对肿瘤进行术前T分期,以术后病理结果作为金标准,比较评价的准确性及其与术后病理结果的一致性;其中30例患者再行DCE-MRI检查并使用Omni-Kinetics软件对图像进行后处理,以获得定量参数包括容量转移常数(Ktrans)、速率常数(Kep)、细胞外血管外间隙容积比(Ve)。收集术后患者病理结果及其分期,回顾性分析比较不同T分期患者间后处理参数间的差异。结果:70例直肠癌患者中正确分期60例,错误分期10例。HR-MRI对直肠癌术前T分期与病理分期结果的一致性均较好,其中≤T2期:Kappa为0.771,P<0.05;准确性90.00%,敏感度79.17%,特异度95.65%,阳性预测值(PPV) 90.48%,阴性预测值(NPV) 89.80%。T3期:Kappa为0.736,P<0.05;准确性87.14%,敏感度90.00%,特异度83.33%,PPV 87.80%,NPV 86.21%。T4期:Kappa为0.683,P<0.05,准确性94.29%,敏感度83.33%,特异度95.31%,PPV 62.50%,NPV 98.39%。不同病理T分期直肠癌的Ktrans和分期的增加,Ktrans和Kep值不断增加;Ve值的差异无统计学意义。结论:HR-MRI对直肠癌术前T分期具有重要的诊断价值,有助于确定癌肿在直肠壁的浸润深度,帮助临床进行术前评估;DCE-MRI定量参数Ktrans和Kep值对直肠癌的T分期具有一定的预测价值。

Objective:To explore the clinical significance and value of high-resolution magnetic resonance imaging(HR-MRI) and dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)in preoperative diagnosis and pathological T staging of rectal cancer. Methods:From Mar 2017 to Feb 2018,70 patients with rectal cancer who underwent colorectal biopsy at the Department of Gastrointestinal Surgery,Yijishan Hospital,were selected and none of them received any treatment. Before the operation,GE′s 3.0T MR scanner was used for HR-MRI scan to perform preoperative T staging on the tumor. The postoperative pathological results were used as the gold standard. The accuracy of the evaluation and consistency of its postoperative pathological results were compared. And 30 patients underwent DCE-MRI and post-processing images using Omni-Kinetics software to obtain quantitative parameters including volume transfer constant(Ktrans),rate constant(Kep),extracellular extravascular space volume ratio(Ve). The pathological results and postoperative staging of patients were collected,and the differences in post-processing parameters between patients with different T stages were compared retrospectively. Results:Seventy patients with rectal cancer underwent HR-MRI scans,of which 60 were correctly staged and 10 were incorrectly staged. HR-MRI had good consistency in preoperative T stage and pathological staging of rectal cancer,among which ≤T2 stage:Kappa was 0.771,P<0.05,accuracy was 90.00%,sensitivity was 79.17%,specificity was 95.65 %,positive predictive value(PPV)was 90.48%,negative predictive value (NPV)was 89.80%.T3:Kappa was 0.736,P<0.05,accuracy was 87.14%,sensitivity was 90.00%,specificity was 83.33%,PPV was 87.80%,NPV was 86.21%.T4:Kappa was 0.683,P<0.05,accuracy was 94.29%,sensitivity was 83.33%,specificity was 95.31%, PPV was 62.50%,NPV was 98.39%.The Ktrans and Kep values of different pathological T stage rectal cancers were statistically significant(P<0.05). With the increase of pathological T stage,the Ktrans and Kep values increased continuously,and the difference of Ve values was not statistically significant. Conclusions:HR-MRI has important diagnostic value for preoperative T staging of rectal cancer,which helps to determine the depth of invasion of the tumor in the rectal wall and helps clinical preoperative evaluation. DCEMRI quantitative parameters Ktrans and Kep values for rectal cancer T staging has a certain predictive value.