CT扫描技术优化进展

Optimization of CT scanning technology

随着X射线计算机断层扫描(CT)设备的不断进步,CT检查的适应证放宽,甚至逐渐拓展到良性病变的检查,导致盲目利用CT进行诊断。然而,X射线存在着两种风险:1累积的射线量的风险;2X射线量过低会因图像质量欠佳而导致漏诊。因此,如何在两者之间求得平衡,不仅仅是学术界关注的焦点,同时引发了医学界的高度重视。通过了解X射线辐射的危害、CT辐射剂量、多排螺旋CT的应用、放射防护的目的与原则以及优化CT扫描技术,做到在合理使用低剂量(ALARA)的原则指导下,"曝光剂量个体化",根据诊断需求将曝光剂量降至最低,接受适当噪声的影像,从而减少X射线的辐射剂量,确保患者的安全。

Due to the advance of CT equipment, combined with the current intensifying doctorpatient conflict, the indication of CT examination is relaxed, even expanded to the examination of benign lesions, which contributes to the blind diagnosis using CT or the so-called ＂Casting a big net＂. However, X-rays bring two kinds of risks. One of them is the risk of the accumulated X-rays, the other one is the missed diagnosis resulting from the poor image quality, which is caused by the low amount of radiation. Therefore, how to strike a balance between these two not only becomes the focus of academic circles, but sparks the whole society＇s attention. This article elaborates X-rays hazards, CT radiation does, application of Multiple Detector Spiral CT, purpose and principles of radiological protection and optimization of CT scanning technology. The author believes ＂exposure does individualization＂ can be achieved under the principle of ALARA（as low as reasonably achievable）, or we can even minimize the exposure does according to the requirements of diagnosis and accept the image with appropriate noise.