弥散峰度成像与直肠癌临床病理预后因素的相关性研究

Correlation between diffusion kurtosis imaging and clinical pathological features of rectal adenocarcinoma

目的 探讨弥散峰度成像(DKI)定量参数和表观扩散系数(ADC)与直肠癌临床病理预后因素之间的潜在关系,为临床预测评估直肠癌的恶性程度提供一定的参考依据.方法 对2016年11月—2017年4月山西省肿瘤医院122例术前行MRI检查的直肠腺癌患者的影像和临床资料进行回顾性分析,其中女48例(39.3%)、男74例(60.7%),年龄42~81岁.利用相关软件测得平均表观扩散系数(MD)、平均峰度(MK)和ADC值,通过独立样本t检验或Mann-Whitney U检验、ROC曲线和Spearman相关性分析进行统计学分析.结果 直肠癌高T分期及淋巴结转移与低MD值(r=-0.367、-0.240)和低ADC值(r=-0.391、-0.254)相关,不同分组间差异均有统计学意义(P值均<0.05);同样,不同组织病理学分级的MD值之间差异亦有统计学意义(P<0.05)且呈负相关(r=-0.210,P<0.05);随着组织病理学分级的升高、淋巴结受累、瘤周血管浸润(LVI)或神经侵犯及环周切缘(CRM)受侵,MK值相应增大,差异均有统计学意义(P值均<0.05)呈正相关(r=0.478、0.206、0.237、0.228,P值均<0.05).MD、MK和ADC值均与淋巴结转移有相关(P值均<0.01)性;ROC曲线显示MK值较其他参数在诊断淋巴结转移与否的曲线下面积高为0.784(95%CI 0.703~0.865),当其阈值取0.984时,具有较高的敏感度及特异度,分别为65.9%和88.7%.结论直肠癌DKI定量参数值和ADC值,尤其MK值,与其重要的临床病理预后因素均有明显相关性,对于预测直肠癌患者预后有一定意义.

Objective To investigate the potential relationships between diffusional kurtosis imaging ( DKI)-derived parameters and apparent diffusion coefficient( ADC) values and clinicopathological prognostic factors in patients with rectal adenocarcinoma, and provide some reference for the clinical prediction of the malignant degree of rectal cancer. Methods One hundred and twenty-two consecutive patients with rectal adenocarcinoma who underwent MRI examination in the Shanxi Province Tumor Hospital from November 2016 to April 2017 were retrospectively evaluated. Among them, there were 48 females(39. 3%) and 74 males(60. 7%) with aged of 42-81 years. The quantitative parameters including mean diffusivity(MD), mean kurtosis(MK)and ADC were measured with relevant software. Student's t-test or Mann-Whitney U-test, receiver operating characteristic ( ROC ) curves, and Spearman's correlation were used for statistical analysis. Results The ADC and MD were negatively correlated with nodal involvement and tumor T stages (all P values <0. 05). Similarly, there were statistically significant differences between MD values in different histopathological grades and negatively correlated(r= -0. 210, P<0. 05). With the increase of histological grade, lymph node involvement, the presence of lymphangiovascular invasion ( LVI ) and circumferential margin ( CRM ) , the MK values increased correspondingly, and these difference were statistically significant and positively correlated(r=0. 478, 0. 206, 0. 228, all P values<0. 05). The MD, MK and ADC were correlated with nodal involvement(all P values<0. 01). The area under the ROC curve of MK is 0. 784(95%CI 0. 703 -0. 865), MK showed relatively higher area under the curve and higher specificity than other quantitative parameters for differentiation of lesions with nodal involvement. When the&nbsp;cutoff of MD was 0. 984, the corresponding sensitivity and specificity were 65. 9% and 88. 7% respectively. Conclusions DKI-derived parameters and ADC values, especially the MK parameters, are associated with important prognostic factors of rectal cancer, and may has a certain significance for predicting the prognosis of patients with rectal cancer.