【摘要】 目的介绍了一种用半导体电离室测量多排CT辐射剂量的原理和方法,为完善我国现有医疗CT检测规范提供技术信息。方法通过介绍X射线辐射剂量计Barracuda的测量原理和多排CT辐射剂量测量的参数设置依据,并结合在Philip Brilliance iCT 256机器上的应用实例,阐述了用半导体电离室的探测器测量多排CT辐射剂量的关键技术。结果基于CT扫描参数合理设置探测器参数后,多排CT辐射剂量空间分布情况得以较好展示。100 mm长杆空气电离室的测量范围远小于多排CT线束覆盖范围,需要对多排CT辐射剂量测量方法和技术进行更新。结论新型探测器有利于揭示多排CT辐射剂量的特性规律。更多还原

【Abstract】 Objective A mechanism and method of multi-detector or multi-slice CT dosimetry based on semi-conductor slice ionization chamber was introduced to provide technical information for the existing medical CT inspection criterion in China.Methods Through the introduction of X-ray dosimeter Barracuda’s detection principle,the basis of relevant parameter setting,and the application examples of Philip Brillinace iCT 256,the key technologies of multi-slice CT dosimetry was expounded.Results The spatial distribution of CT radiation dosage could be illustrated well by the detector with the slice ionization chamber after proper parameter setting.A pencil ionization chamber with a length of 100 mm was not sufficient to cover the irradiating range by X-ray beam of multi-slice CT,which was expected to renew the detection technology of radiation dosage for multi-slice CT.Conclusions This new detector is helpful to reveal the characteristics of the radiation dosage regularity in multi-slice CT.更多还原