扩散加权成像对直肠癌患者根治术后局部复发的诊断价值

Diagnostic value of diffusion weighted imaging in local recurrence for patients with rectal carcinoma after radical resection

目的研究扩散加权成像(DWI)对直肠癌患者根治术后局部复发的诊断价值。方法选取2016年3月~2018年3月于海南省人民医院(以下简称“我院”)接受根治术治疗且术后局部复发的直肠癌患者60例为复发组。另取同期于我院接受根治术治疗,但术后局部无复发的直肠癌患者60例为对照组。所有患者均予以常规磁共振成像(MRI)以及DWI检查。分别比较常规MRI与DWI诊断直肠癌患者根治术后局部复发的结果,复发组与对照组的信号强度值、表观弥散系数(ADC值)、对比信噪比(CNR)水平;采用受试者工作特征曲线(ROC)分析常规MRI以及DWI在直肠癌患者根治术后局部复发中的诊断效能。结果直肠癌患者根治术后局部复发常规MRI表现为术区肠壁的不均匀增厚,呈稍长T1、长T2信号,DWI序列上信号显著增高,在ADC图上呈低信号;直肠癌患者根治术后局部无复发者组瘢痕组织呈轻度强化。复发组的信号强度值、CNR水平高于对照组,而ADC值低于对照组,差异有统计学意义(均P <0.05)。经ROC曲线分析,发现常规MRI诊断直肠癌患者根治术后局部复发的敏感度为92.00%,特异度为95.00%,曲线下面积(AUC)为0.731;DWI诊断直肠癌患者根治术后局部复发的敏感度为96.00%,特异度为93.00%,AUC为0.815;其中DWI的AUC高于常规MRI,但差异无统计学意义(均P> 0.05)。结论 DWI对直肠癌患者根治术后局部复发的诊断价值较高,较常规MRI具有较高的诊断效能,值得临床推广应用。

Objective To study the diagnostic value of diffusion weighted imaging (DWI) in local recurrence for patients with rectal carcinoma after radical resection. Methods A total of 60 patients with rectal carcinoma who received radical resection in Hainan General Hospital ("our hospital" for short) from March 2016 to March 2018 and had local recurrence after surgery were selected as the recurrence group. Another 60 patients with rectal carcinoma who received radical resection in our hospital at the same time without local recurrence after surgery were enrolled as the control group. All patients were examined by conventional magnetic resonance imaging (MRI) and DWI. The results of local recurrence after radical resection in rectal carcinoma patients diagnosed by conventional MRI and DWI, signal intensity value, the levels of apparent diffusion coefficient (ADC value), contrast signal to noise ratio (CNR) were compared between recurrence group and control group. The diagnostic efficacy of conventional MRI and DWI in local recurrence of rectal carcinoma patients after radical resection were calculated by receiver operator characteristic curve (ROC). Results Conventional MRI showed that the local recurrence of rectal carcinoma patients after radical resection showed uneven thickened of intestinal wall, slightly long T1, long T2 signal, the signal on DWI sequence increased significantly and showed low signal on ADC map, and slight enhancement of scar tissue in patients without local recurrence after radical resection. The signal intensity value and CNR level of the recurrence group were higher than that of the control group, while the ADC value was lower than that of the control group, and the differences were statistically significant (P < 0.05). ROC curve analysis showed that the sensitivity of conventional MRI in the diagnosis of local recurrence after radical resection for rectal cancer was 92.00%, the specificity was 95.00%, and the area under the curve (AUC) was 0.731. The sensitivity of DWI in the diagnosis of local recurrence after rectal cancer was 96.00%, specificity was 93.00%, AUC was 0.815. The AUC of DWI was higher than that of conventional MRI, but the difference was not statistically significant (P > 0.05). Conclusion DWI has higher diagnostic value for local recurrence of rectal carcinoma patients after radical resection, and has higher diagnostic efficiency than conventional MRI. It is worthy of clinical application.