辐射剂量对头颅CT扫描图像质量的影响

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～ 14 0kV ,180～ 36 0mAs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 ,12 0kV、2 40mAs以上组影像质量均达优良 ;130kV、30 0mAs以上组优片率更高。结论 :采用适当辐射剂量 ( >12 0kV、2 40mAs)行颅脑CT扫描能提高密度分辨力 ,增加SNR ,改善影像质量

A study for imaging quality in the course of plain cranial CT scans with different radiation doses

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.