直肠癌3.0T磁共振弥散加权成像及其与病理的相关性研究

3.0T MR diffusion-weighted imaging in rectal cancer diagnosing and researching with pathology

目的探讨3.0T磁共振背景抑制弥散加权成像(diffusion-weighted imaging with background suppression,DWIBS)对直肠癌的诊断价值,并分析其肿瘤表观弥散系数(apparent diffusion coefficient,ADC)值与病理的相关关系。方法收集42例直肠癌患者术前盆腔常规MRI及DWI的扫描资料,所有患者均接受直肠癌切除并病理组织学检查。测量肿瘤及正常直肠肠壁的ADC值并进行统计学分析。结果 (1)直肠癌组与对照组的ADC值分别为(0.76±0.11)×10-3mm2/s和(1.22±0.16)×10-3mm2/s,两组比较差异有统计学意义(P<0.001)。鉴别直肠癌与正常直肠肠壁的ADC值的最佳分界值为0.96×10-3mm2/s,敏感性为95.2%,特异性为97.6%。(2)1例高分化,33例中分化及5例低分化直肠腺癌的ADC值分别为0.78×10-3mm2/s,(0.75±0.12)×10-3mm2/s及(0.77±0.11)×10-3mm2/s。中分化与低分化直肠腺癌的ADC值比较差异无统计学意义(P>0.05)。结论 3.0T磁共振DWI能提高直肠癌的检出率,直肠癌原发灶的ADC值明显低于正常直肠肠壁的ADC值,不同分化程度的直肠腺癌的ADC值间无统计学差异。

Objective To evaluate the efficacy of diffusion-weighted imaging with background suppression （DWIBS） at 3.0T magnetic resonance （MR） for diagnosing rectal cancer, and analyze the relationship between apparent diffusion coefficient （ADC） values and pathological results of tumor. Methods The study included 42 patients with rectal cancer who underwent preoperative routine MRI ＋ DWI examination and were treated by rectal cancer dissection, and then obtained pathological results. ADC values of tumors and normal rectal walls were measured respectively, and statistical analysis was made. Results （ 1 ） The ADC values of total 42 patients of rectal primary tumors and normal rectal wall were （0.76± 0.11） × 10-3 mmE/s and （1.22± 0.16） × 10-3 mm2/s respectively. The ADC value of rectal cancer was statistically significant different from that of the normal rectal wall tissue （t -- 15.439,P 〈 0.001 ）. The optimal cutoff ADC value in differentiating rectal cancer from normal rectal wall was （0.96 × 10-3） mmE/s, representing 95.2% sensitivity and 97.6% specificity. （2） The ADC values of one case of well differentiated, 33 cases of moderately differentiated and 5 cases of poorly differentiated rectal adenocarcinoma were 0.78× 10-3 mm2/s, （0.75 ± 0.12） x 10-3 mmE/s and （0.77 ± 0.11） × 10-3romE/s, respectively. There was no statistically difference between moderately differentiated and poorly differentiated rectal adenocarcinoma in ADC value （P 〉 0.05）. Conclusions 3.0T MR diffusion- weighted imaging can improve the tumor detection rate of rectal cancer. The ADC value of primary tumor is significantly lower than the normal rectal wall, and there is no statistically difference between different degrees of differentiation of rectal adenocarcinoma in ADC value.