CT scan with suitable scan slice and pitch can provide better quality of CT image, and decrease the examining time and the roentgen patient taken.

• 螺旋CT实际层厚与扫描层厚、螺距有密切关系,选择合适的扫描层厚及螺距对提高CT图像质量、减少扫描时间、减少病人接受的放射剂量均大有益处。