3.0 T MR胃癌扩散加权成像——单序列分次屏气与分序列单次屏气比较研究

3.0 T Magnetic Resonance Diffusion-Weighted Imaging in Gastric Cancer: Comparison of A Single Breath-Hold Sequences and Separate Breath Holds Sequence

目的比较3.0 T MR单序列分次屏气与分序列单次屏气在胃癌扩散加权成像(diffusion weighted ima-ging,DWI)的信噪比(SNR)、对比噪声比(CNR)、表观扩散系数(ADC)值和伪影等方面的差异。资料与方法对经胃镜病理证实的18例胃癌患者行术前MR DWI检查,均行单序列分次屏气与分序列单次屏气两次扫描,比较两种检查方法的SNR、CNR、ADC值及伪影等影响图像质量的因素,以及胃癌与正常胃壁ADC值之间的差异。结果18例胃癌DWI图像上均显示为高信号,两种检查方法间正常胃壁及癌肿ADC测量差异无统计学意义(P>0.05),而单次屏气DWI的SNR、CNR明显高于分次屏气扫描,单次屏气胃腔内自由水以及背景噪声信号强度明显低于分次屏气扫描,差异均有统计学意义(P<0.05);单次屏气法DWI图像的呼吸运动及并行采集空间敏感性编码技术(ASSET)伪影明显减轻;胃癌ADC值与正常胃壁ADC值间比较差异有统计学意义(t=-10.167,P<0.001),胃癌组明显低于正常胃壁组ADC值。结论 3.0 T MR胃癌DWI中单次屏气图像质量明显优于分次屏气扫描,胃癌ADC值明显低于正常胃壁ADC值,具有很好的临床应用价值。

Objective To compare the single breath hold and separate breath hold sequence diffusion weighted imaging in gastric cancer.Materials and Methods Eighteen patients with gastric cancer proved by pathology underwent preoperative MRI DWI examination with single breath hold and separate breath hold sequence.The SNR,CNR and apparent diffusion coefficient（ADC value） of two kinds of sequence were compared.Results Gastric cancer lesions showed high signal on DWI images.The SNR and CNR of single breath hold were significantly higher than that of separate breath hold scan.Gastric lumen water and background noise signal intensity single of single breath were significantly lower than that of separate breath hold scan（P0.05）.Respiratory and ASSET artifacts of single breath hold DWI images were significantly reduced.ADC values of gastric cancer were significantly lower than that of normal gastric wall（t=-10.167,P0.001）.Conclusion The DWI image quality of gastric cancer with single breath hold was better than that of separate breath hold.