基于特定条件下头颅模体螺旋扫描与轴位扫描的图像质量和辐射剂量的对比研究  

Comparative study on image quality and radiation dose between the spiral scanning and the axial scanning for skull phantom based on specific conditions

作　　者：高志远 隋岩 刘康 陈钊睿 郑爽爽[1] 杨德武 Gao Zhiyuan;Sui Yan;Liu Kang;Chen Zhaorui;Zheng Shuangshuang;Yang Dewu(Department of Radiology,Fuxing Hospital,Capital Medical University,Beijing 100038,China;Department of Medical Technique,Beijing Health Vocational College,Beijing 102433,China)

机构地区：[1]首都医科大学附属复兴医院放射科,北京100038 [2]北京卫生职业学院医学技术系,北京102433

出　　处：《中国医学装备》2024年第9期18-22,共5页China Medical Equipment

摘　　要：目的:探讨特定条件下头颅模体使用螺旋扫描与轴位扫描的图像质量和辐射剂量对比研究。方法:将头颅模体听眦线(OBL)位置进行标记,调整不同头颅仰角,分别设置OBL与床面呈90°、100°、110°和120°,使用轴扫与螺旋两种扫描模式,固定容积CT剂量指数(CTDI_(vol))为40、50和60 mGy进行24次图像采集。轴位扫描横断面与OBL垂直,螺旋扫描图像使用去螺旋伪影的图像质量增强(IQE)重建技术沿OBL方向重建。测量模体双侧小脑、颞叶、额叶及顶叶的CT值(HU)与标准差(SD),计算模体各脑叶图像信噪比(SNR)。记录图像CTDI_(vol)、剂量-长度乘积(DLP),计算眼晶体有效剂量(ED)。结果:两种扫描模式下模体颅脑横断位图像脑区的小脑与枕叶(R)、小脑与枕叶(L)、颞叶(R)、颞叶(L)、额叶(R)、额叶(L)、顶叶(R)和顶叶(L)信噪比比较,差异有统计学意义(F=6.48、5.83、7.00、6.20、7.30、8.26、5.72、5.83,P<0.05);两组扫描模式下图像的眼晶体DLP比较,差异有统计学意义(F=10.96,P<0.05)。使用螺旋扫描和IQE重建技术进行图像采集与处理,在相同CTDI_(vol)时螺旋扫描图像的SNR优于轴位扫描,且可进行冠、矢状位重建,晶状体辐射剂量相近,但DLP略高于轴扫,结论:在机器无法更改扫描角度或轴位扫描无法配合的情况下,使用螺旋扫描IQE重建技术可获得满意的头部CT断层图像。Objective:To explore and compare the image quality and radiation dose between the spiral scanning and the axial scanning for skull phantom based on specific conditions.Methods:The position of the orbitomeatal base line(OBL)of the skull phantom was marked,and the different angles of elevation of skull were adjusted.The angles between OBL and bed surface were respectively set as 90°,100°,110°and 120°.The axial scanning and spiral scanning were respective adopted to conduct 24 times of image acquisition when the computed tomography dose index(CTDI_(vol))of fixed volume were respectively 40,50 and 60 mGy.The cross section of axial scanning was vertical to OBL,and the images of spiral scanning used the reconstructed technique of image quality enhancement(IQE)of removing spiral artifacts to conduct reconstruction along the OBL direction.The CT value(HU)and standard deviation(SD)of the bilateral cerebellum,temporal lobe,frontal lobe and parietal lobe of the phantom were measured,and the signal-to-noise ratio(SNR)of each lobe of the phantom was calculated.The CTDI_(vol) and dose-length product(DLP)were recorded,and the effective dose(ED)of lens was calculated.Results:The differences of the SNR values of cerebellum and occipital lobe(R),cerebellum and occipital lobe(L),temporal lobe(R),temporal lobe(L),frontal lobe(R),frontal lobe(L),parietal lobe(R)and parietal lobe(L)between two kinds of scanning models were significant(F=6.48,5.83,7.00,6.20,7.30,8.26,5.72,5.83,P<0.05),respectively.There was significant difference in lens DLP between the two kinds of scanning models(F=10.96,P<0.05).The spiral scanning and IQE reconstructed technique were used to conduct image acquisition and processing.The SNR value of spiral scanning imaging was better than that of axial scanning,and the reconstructions of coronal and sagittal positions could be conducted,and the radiation doses of lens were similar,but the DLP value of spiral scanning was slightly higher than that of axial scanning at the same CTDIvol.Conclusion:Using the IQE reco

关 键 词：头颅CT 螺旋扫描 轴位扫描 图像质量 辐射剂量 

分 类 号：R814.2[医药卫生—影像医学与核医学]