中文摘要：

目的 探讨低张法在胃癌CT检查前处置流程中的价值。方法 分别连续入组低张和未行低张CT扫描胃癌患者各52例。根据CT图像盲法评判胃壁各部扩张伸展的情况,轴位图像测量正常胃壁厚度,联合轴位、冠状位、矢状位观察蠕动波情况。结合各参数对图像质量主观分级。卡方检验、t检验及秩和检验比较两组CT征象及图像质量差异。结果 非低张组正常胃壁厚度大于5mm的比例高于低张组（P〈0.001）。非低张组蠕动波出现比例高于低张组（P=0.001）。低张组图像质量分级优于非低张组（P〈0.001）。结论 低张是胃癌CT检查前处置的重要环节,可延缓胃排空、降低胃壁张力、减少蠕动波,使胃壁充分扩张,利于癌肿检出和范围的判断。

英文摘要：

Objective To investigate the values of hypotonic procedures in the CT imaging of gastric cancer. Methods Fifty- two consecutive gastric cancer patients who underwent hypotonic CT examinations and 52 consecutive patients with non-hypotonic procedure were enrolled in study. The extension degrees of various parts of gastric wall on CT were evaluated with blind method. The thickness of normal gastric wall was measured on axial plane. The appearance of peristaltic wave was observed with combination of axial, coronal and sagittal planes. The subjective image scoring was evaluated through the combination of several imaging quality parameters. Chi-square test, t-test and Kolmogorov-Smirnov test were used to determine the difference between two groups. Results The ratio of thickness larger than 5 mm in normal gastric wall in non-hypotonic group was higher than that of hypotonic group（ P 〈 0. 0 0 1 ） . The peristaltic wave displayed more frequently and severe in non - hypotonic group than in hypotonic group （ P =0. 001 ）. The hypotonic group outperformed non-hypotonic group in subjective image scoring （ P 〈0. 001 ）. Conclusion Hypotonia is a key procedure of gastric cancer CT examination, with which to slow stomach empty, to minimize the tension of gas- tric wall, to reduce peristaltic wave, to get sufficient distention of gastric wall, and to facilitate the detection of lesions and border judgment.