磁共振扩散加权成像ADC直方图评估胃癌异质性及其淋巴结转移

项目名称： 磁共振扩散加权成像ADC直方图评估胃癌异质性及其淋巴结转移

项目编号： No.81501441

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 医药、卫生

项目作者： 何健

作者单位： 南京大学

项目金额： 17万元

中文摘要： 胃癌是全球最常见的消化道恶性肿瘤之一，占癌症相关死亡原因的第2位。胃癌的术前诊断和评估目前主要依赖钡餐造影、超声内镜和CT检查。磁共振软组织分辨率高，无辐射，能够提供更加丰富的诊断信息。磁共振扩散加权成像（DWI）能够在活体内无创检测水分子的扩散运动，目前已被广泛运用于全身各种肿瘤的检测和评估。胃为空腔脏器，DWI成像存在一定的困难。国内外初步研究表明，DWI在胃癌的检测、评估方面具有独特的价值。DWI定量分析方法是在病灶内画感兴趣区（ROI），获取平均表观扩散系数（ADC）值。研究发现，胃癌的ADC值显著低于正常胃壁。但是基于ROI的平均ADC值无法反映胃癌病灶的异质性。ADC直方图能够更加全面地刻画病灶内部的结构特征。该方法目前主要应用于颅脑病变，胃癌方面未见报道。本研究拟采用ADC直方图分析胃癌病灶的异质性，并尝试鉴别和预测其淋巴结转移。

中文关键词： 磁共振成像；扩散加权成像；直方图；胃癌；淋巴结

英文摘要： Gastric cancer is one of the most common malignant tumor of digestive tract all over the world, accounting for the second cause of cancer-related death. Preoperative diagnosis and assessment of gastric cancer mainly rely on barium meal, endoscopic ultrasonography and CT examination. Magnetic resonance imaging shows high resolution of soft tissues, without radiation, and can provide plenty of diagnostic information. Diffusion weighted magnetic resonance imaging (DWI) could detect the Brownian motion of water molecule in vivo and noninvasively. DWI has been widely used in detection and assessment of various body tumors. DWI of the stomach, a hollow viscera, is somewhat challenging. Domestic and international preliminary studies show that DWI has a unique value in detection and assessment of gastric cancer. Quantitative analysis method in DWI is to draw a region of interest (ROI) and obtain the mean apparent diffusion coefficient (ADC) value. It was reported that the ADC value of gastric cancer was significantly lower than that of normal gastric wall. However, mean ADC value based on ROI measurement can not reflect the heterogeneity of gastric lesion. The ADC histogram can characterize the internal structures of the lesions more comprehensively. This method is mainly used in brain lesions without any report on gastric cancers. Our team has accumulated rich experience in DWI of gastric cancers, and got some achievement. The aim of this study is to analyze the heterogeneity of gastric cancer with ADC histogram analysis, and try to identify and predict the lymph node metastasis.

英文关键词： magnetic resonance imaging;diffusion weighted imaging;histogram;gastric cancer;lymph nodes