不同双源CT头颈部扫描模式对影像质量及辐射剂量的影响

摘要

目的：分析不同双源CT头颈部扫描模式对影像质量及辐射剂量的影响。方法分别采用6种双源CT头颈部扫描模式，对仿真模体头颈部进行扫描，评价不同扫描模式对头颈部影像质量和辐射剂量的影响。结果（1）20 kV+200 mAs、120 kV+200 mAs+X-Care以及CareDose4D+120 kV 3种扫描模式下的头颅CNR基本相同。其余3种扫描模式，以CareDose4D+CarekV扫描模式的影像质量为最高。（2）与自动mAs和固定kV组合相比，使用自动kV可使CTDIvol、表浅辐射敏感器官剂量减小，但影像质量也有一定程度降低。扫描的影像质量与辐射剂量CTDIvol、晶体辐射剂量、甲状腺辐射剂量的变化规律呈正相关。结论头颈部双源CT扫描在临床实践中，应选择适当的扫描模式以降低辐射剂量。%Objective To analyze the effects of different dual-source CT scans on image quality and radiation dose. Methods By using 6 kinds of dual source CT in head and neck scanning mode to scan the simulation model of head and neck, head and neck effect evaluation of different scanning modes of image quality and radiation dose.Results(1) The head CNR in the three scan modes of 20 kV+200 mAs, 120 kV+200 mAs+X-Care and CareDose4D+120 kV are basically the same. The remaining three scan modes are the highest image quality in the CareDose4D + CarekV scan mode. (2) Compared with the combination of automatic mAs and ifxed kV, automatic kV can reduce CTDIvol and superifcial radiation-sensitive organ dose, but the image quality is also reduced to a certain extent. The image quality was positively correlated with the dose of CTDIvol, crystal radiation dose and thyroid radiation dose.Conclusion In the clinical practice, dual-source CT scan of head and neck should be selected to reduce the radiation dose.