辐射剂量对头颅CT扫描图像质量的影响

摘要

目的：探讨不同辐射剂量行颅脑CT扫描对影像质量的影响。方法：8例正常男性志愿者用110～140kV，180～360mAs分四组行轴位平扫；各影像按颗粒均匀性、脑灰白质细节、界面清晰度和有无射线硬化等积分评定质量。结果：共扫描192次，120kV、240mAs以上组影像质量均达优良；130kV、300mAs以上组优片率更高。结论：采用适当辐射剂量(＞120kV、240mAs)行颅脑CT扫描能提高密度分辨力，增加SNR，改善影像质量。%Objective: To evaluate the effect of different radiation doses to imaging quality in the course of plain cranial CT scans.Methods:Eight normal male volunteers were divided into four groups,and each group was performed plain cranial axial CT scans with 110,120,130,140kV and 180 ～ 360mAs respectively. All images were scored at four degrees (excellent, good, poor, very poor) according to grain homogeneity, fine structure appearance of the grey and white matter, hardening of X rays and clearness of tissue interface. Results:The patients were totally scanned 192 times. The image quality with ＞ 120kV and ＞ 240mAs is excellent or good. The rate of superior image quality with ≥ 130kV and≥300mAs, moreover, was higher. Conclusion:Using radiation dose with ＞ 120kV and ＞ 240mAs, the density resolution and SNR may be increased and imaging quality be improved.