扩散加权成像(DWI)在诊断胃肠道恶性肿瘤中的价值

The value of diffusion weighted imaging in diagnosing the gastrointestinal malignant tumors

目的:探讨扩散加权成像(diffusion weighted imaging,DWI)在诊断和鉴别胃肠道恶性肿瘤中的价值。方法:收集经病理确诊的胃肠道恶性肿瘤患者32例,其中胃低分化腺癌18例,胃神经内分泌癌7例和胃、十二指肠淋巴瘤7例,选取15例健康志愿者作为正常对照组。所有患者和志愿者均行MRI平扫、增强扫描和DWI成像(序列包括T_1WI、T_2WI、DWI)。分析肿瘤的影像学表现,经工作站处理获得肿瘤组织和正常胃壁组织的T_2信号强度和表观扩散系数(Apparent diffusion coefficient,ADC)值,并进行统计学分析。结果:所有肿瘤组织在T_2上呈稍高信号,病灶呈不同程度强化。T_2WI上肿瘤组织的平均信号强度明显高于正常胃壁组织,胃腺癌、神经内分泌癌和淋巴瘤组织和正常胃壁组织平均信号强度分别为415.36±150.61、408.67±88.19、320.53±63.37和201.83±45.92,肿瘤组织和正常胃壁组织信号强度比较差异具有统计学意义(P<0.05)。DWI上肿瘤组织呈明显高信号,胃低分化腺癌、胃神经内分泌癌和胃、十二指肠淋巴瘤平均ADC值显著低于正常胃壁组织:(0.84±0.15)×10^(-3)mm^2/s、(0.91±0.23)×10^(-3)mm^2/s、(1.25±0.38)×10^(-3)mm^2/s和(1.85±0.36)×10^(-3)mm^2/s,3种肿瘤组织ADC值与正常组织之间比较差异有统计学意义(P<0.05),胃腺癌、神经内分泌癌与淋巴瘤组织ADC值之间差异具有统计学意义(P<0.05),但胃腺癌和神经内分泌癌之间结果比较差异不具有统计学意义(P>0.05)。结论:DWI在诊断和鉴别胃肠道恶性肿瘤中具有潜在的应用价值。

Objective：To investigate the value of diffusion weighted imaging（DWI） in diagnosing the gastrointestinal malignant tumors. Methods：32 subjects diagnosed gastrointestinal malignant tumors and confirmed by pathology were enrolled,including poorly differentiated gastric adenocarcinoma（18 cases）,gastric neuroendocrine carcinoma（ 7 cases） and gastrointestinal lymphoma（ 7 cases）. 15 volunteers were selected as control group. All the cancer patients and volunteers were performed on MRI,including plain scanning and contrast enhanced scanning. The T1WI,T2WI and DWI sequences were selected. The main imaging manifestations were observed,the mean signal intensity on T2WI and the ADC values were measured on workstation. The data were analyzed with statistical software. Results：All the tumors showed slightly high signal intensity on T2WI and showed moderate to obvious enhancement after contrast administration. The mean signal intensity of gastric adenocarcinoma,gastric neuroendocrine carcinoma and gastrointestinal lymphoma were apparently higher than the normal tissue on T2WI（ 415. 36 ± 150. 61,408. 67 ± 88. 19,320. 53 ± 63. 37 and 201. 83 ±45. 92）. The difference of signal intensity between the tumors and the normal gastric wall tissue was statistically significant.（ P 0. 05）. All the tumors showed hyperintensity on DWI. The mean ADC values of the adenocarcinoma,neuroendocrine carcinoma,lymphoma and the normal were（ 0. 84 ± 0. 15） × 10^-3 mm^2/s,（ 0. 91 ± 0. 23） × 10^-3 mm^2/s,（ 1. 25 ± 0. 38） × 10^-3 mm^2/s and（ 1. 85 ±0. 36） × 10^-3 mm^2/s,respectively. There was a significant difference between the ADC values of 3 tumor tissues and normal tissues（P 0. 05）. In addition,the statistical significance was also found between adenocarcinoma,neuroendocrine carcinoma,and lymphoma（P 0. 05）,but no statistical significance was also found between adenocarcinoma and neuroendocrine carcinoma（P 0. 05）. Conclusion：DWI has potential application value in diagnosis and differentiation of gastrointestinal malignant tumors.