Zheng Guodian, Cheng Xiangdong, Wang Lijing, Xu Zhiyuan, Gao Xuning, Yu Pengfei, Lyu Hang, Huang Ting, Chen Jiahui
Department of Clinical Medicine Surgery, The First Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou 310053, China.
Department of Gastrointestinal Surgery, Zhejiang Provincial Hospital of Traditional Chinese Medicine, Hangzhou 310006, China.
Zhonghua Wei Chang Wai Ke Za Zhi. 2017 Jul 25;20(7):803-808.
To study the correlation between MRI apparent diffusion coefficient (ADC) and expression of Ki-67 in gastric cancers, and to investigate the application of ADC value in diagnosing the malignance of gastric cancer.
A retrospective cohort analysis was performed on 87 gastric cancer patients who received MRI examination and radical resection at Zhejiang Provincial Hospital of Traditional Chinese Medicine from November 2014 to August 2015. All the postoperative resected samples were confirmed as gastric cancer. Preoperative MRI examination was performed by using Siemens 3.0-T Verio MRI with following parameters: section thickness 3 mm, gap 1 mm, matrix 182×320, field of view 40 cm. Plain scan was followed by T1-weighted fat suppression technique VIBE 3D(TR3.92/TE1.39,90degree) scans at arterial phase (the 30th second), portal venous phase (the 60th second), lag period (the 90th second), axial planes and coronal planes (the 180th second), and sagittal planes (the 210th second), respectively. ADC value of tumor was measured at b-factor of 800 s/mm and ADC map was generated from DWI data on the work station. The expression of Ki-67 in cancer tissue was detected by routine immunohistochemical (SP) staining after surgery. Correlation between ADC value and the expression of Ki-67 in gastric cancer was analyzed.
Irregular thickening of the gastric wall and inhomogeneous enhancement of the tumor after injection of the contrast material appeared in gastric cancer. Gastric cancer tissue presented hyperintensity and normal gastric wall presented isointensity in DWI image (b=800 s/mm). Compared with normal gastric tissue, mean ADC value of gastric cancer tissue was significant lower [(1.114±0.265)×10 mm/s vs. (2.032±0.202)×10 mm/s, t=26.209, P=0.000]. The ADC values of high-middle differentiation group, middle-low differentiation group, low differentiation group and signet ring cell carcinoma/mucinous adenocarcinoma group were (1.347±0.234)×10 mm/s, (1.179±0.257)×10 mm/s, (0.996±0.185)×10 mm/s and (1.082±0.230)×10 mm/s, respectively. The difference of mean ADC value among different tumor stages was significant(F=8.498, P=0.000). Along with the Ki-67 expression up-regulated, the ADC value decreased in cancer tissue. The Ki-67 expressions in cancer tissue was negatively correlated with cancer ADC values (r=-0.570, P=0.000). Furthermore, negative correlations of Ki-67 expressions with ADC values of high-middle differentiation group (r=-0.627, P=0.016), low differentiation group (r=-0.787, P=0.000) and signet ring cell carcinoma/mucinous adenocarcinoma group (r=-0.792, P=0.000) were observed respectively, while Ki-67 expression was not correlated with ADC value of middle-low differentiation group.
The ADC value of gastric cancer can reflect the level of tumor differentiation, and is negatively correlated with Ki-67 expression in cancer tissues.
研究胃癌磁共振成像表观扩散系数（ADC）与Ki-67表达的相关性，探讨ADC值在胃癌恶性程度诊断中的应用。
对2014年11月至2015年8月在浙江省中医院接受磁共振成像检查并接受根治性手术的87例胃癌患者进行回顾性队列分析。所有术后切除标本均确诊为胃癌。术前采用西门子3.0-T Verio磁共振成像仪进行检查，参数如下：层厚3 mm，层间距1 mm，矩阵182×320，视野40 cm。平扫后分别于动脉期（第30秒）、门静脉期（第60秒）、延迟期（第90秒）采用T1加权脂肪抑制技术VIBE 3D（TR3.92/TE1.39，90°）扫描，扫描轴位、冠状位（第180秒）和矢状位（第210秒）。在b值为800 s/mm时测量肿瘤的ADC值，并在工作站上根据扩散加权成像（DWI）数据生成ADC图。术后采用常规免疫组织化学（SP）染色检测癌组织中Ki-67的表达。分析胃癌ADC值与Ki-67表达的相关性。
胃癌表现为胃壁不规则增厚，注射对比剂后肿瘤强化不均匀。在DWI图像（b=800 s/mm）中，胃癌组织呈高信号，正常胃壁呈等信号。与正常胃组织相比，胃癌组织的平均ADC值显著降低[（1.114±0.265）×10⁻³mm²/s vs.（2.032±0.202）×10⁻³mm²/s，t=26.209，P=0.000]。高中分化组、中低分化组、低分化组和印戒细胞癌/黏液腺癌组的ADC值分别为（1.347±0.234）×10⁻³mm²/s、（1.179±0.257）×10⁻³mm²/s、（0.996±0.185）×10⁻³mm²/s和（1.082±0.230）×10⁻³mm²/s。不同肿瘤分期的平均ADC值差异有统计学意义（F=8.498，P=0.000）。随着癌组织中Ki-67表达上调，ADC值降低。癌组织中Ki-67表达与癌组织ADC值呈负相关（r=-0.570，P=0.000）。此外，分别观察到Ki-67表达与高中分化组（r=-0.627，P=0.016）、低分化组（r=-0.787，P=0.000）和印戒细胞癌/黏液腺癌组（r=-0.792，P=0.000）的ADC值呈负相关，而Ki-67表达与中低分化组的ADC值无相关性。
胃癌的ADC值可反映肿瘤分化程度，且与癌组织中Ki-67表达呈负相关。
