摘要
目的通过实验分析重建层厚的改变对CT图像噪声的影响。方法应用Siemens Somatom Sensation 16全身CT机及随机所配20cm直径水模。选用不同的扫描参数及重建层厚,对水模进行扫描,测量图像中心相同位置CT值与标准值偏差并分析。结果CT图像噪声随着mAs值、重建层厚增大而减小,图像噪声与mAs的平方根成反比。结论正确理解重建层厚对噪声的影响,采用适当增加X线毫安量的方法来降低噪声是切实可行的。
Objective To analyze experimentally the influence of changing mAs and reconstruction slice thickness on spiral CT image noise. Methods Using Siemens Somatom Sensation 16 CT scanner and its phantoms （diameter 20cm）, We adopted different scanning parameters and different reconstruction slice thickness in computer soft testing system. And all of these CT standard deviation in center of image were measured and analyzed. Results The noise is decreased with mAs and reconstruction slice thickness increasing. The noise is inversely related with the square root of mAs, Conclusion It is practical to decrease image noises by properly increasing mAs.
出处
《中国医疗设备》
2008年第8期12-13,38,共3页
China Medical Devices
关键词
螺旋CT
重建层厚
图像噪声
Spiral CT
reconstruction slice thickness
image noise
