扩散加权成像(DWI)在诊断胃肠道恶性肿瘤中的价值

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T1WI、T2WI、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T2信号强度和表观扩散系数( Apparent diffusion coeffi-cient,ADC)值,并进行统计学分析.结果: 所有肿瘤组织在T2上呈稍高信号,病灶呈不同程度强化. T2WI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)×10-3mm2/s 、(0. 91 ± 0. 23)×10-3mm2/s、(1. 25 ± 0. 38)×10-3mm2/s和(1. 85 ± 0. 36)×10-3mm2/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.

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

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 ca-ses). 15 volunteers were selected as control group. All the cancer patients and volunteers were performed on MRI,including plain scan-ning and contrast enhanced scanning. The T1WI,T2WI and DWI sequences were selected. The main imaging manifestations were ob-served,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 con-trast administration. The mean signal intensity of gastric adenocarcinoma,gastric neuroendocrine carcinoma and gastrointestinal lympho-ma 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,lympho-ma and the normal were (0. 84 ± 0. 15)×10 -3mm2/s,(0. 91 ± 0. 23)×10 -3mm2/s,(1. 25 ± 0. 38)×10 -3mm2/s and (1. 85 ± 0. 36)×10 -3mm2/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). Conclu-sion:DWI has potential application value in diagnosis and differentiation of gastrointestinal malignant tumors.