基于模体实验的能谱CT血管成像检查扫描触发阈值优化的研究  

Optimized Bolus Threshold for Dual-Energy CT Angiography with Virtual Monoenergetic Images:A Phantom Study

作　　者：董淑雯 陈洁琼 崔园园 于清扬 范丽 DONG Shuwen;CHEN Jieqiong;CUI Yuanyuan;YU Qingyang;FAN Li(Department of Radiology,Second Affiliated Hospital of Naval Medical University)

机构地区：[1]海军军医大学第二附属医院放射诊断科

出　　处：《中国医学计算机成像杂志》2024年第5期628-631,共4页Chinese Computed Medical Imaging

基　　金：国家自然科学基金项目(82171926,81930049,82202140);国家重点研发计划(2022YFC2010000,2022YFC2010002,2022YFC2010005);上海市科委项目(21DZ2202600);慢性阻塞性肺疾病CT标准化数据库建设(YXFSC2022JJSJ002);上海市扬帆项目(20YF1449000);上海市长征医院临床创新项目(2020YLCYJ-Y24)

摘　　要：目的:基于模体实验探究能谱CT结合虚拟单能谱影像(VMI)后处理方法的CT血管成像(CTA)检查的最佳触发阈值。方法:6个不同浓度的碘造影剂血管模体行能谱CT增强扫描(120 kV/30 mA),并对扫描图像进行40~70 keV VMI后处理分析。由2名放射科医生分别测量6个血管模体常规CT扫描图像与不同VMI后处理图像的CT值,并将常规扫描图像与40~70 keV VMI后处理图像的平均CT值进行二项式回归模型拟合。结果:根据线性回归方程可以得到40 keV VMI下对应的δ值为45 HU。最佳触发阈值=基础平扫+45 HU。结论:使用40 keV VMI对CTA检查图像进行后处理后,扫描时触发阈值可降低至原触发阈值的64%。Purpose:To investigate the optimal bolus-tracking trigger threshold in low contrast medium protocol using 40 keV virtual monoenergetic images(VMI)on spectral CT in an angiography phantom.Methods:Six syringes with different densities of diluted iodide contrast medium were made as the angiography phantom.The angiography phantom were scanned on a spectral detector CT with 120 kV/30 mA.40-70 keV VMI reconstruction were performed on the angiography phantom images.CT attenuation of six syringes were measured by two radiologists in both conventional scan images and 40 keV VMI.The CT values corresponding to the conventional scan images and the 40-70 keV VMI were calculated using least-squares estimation from polynomial regression models with a quadratic term and the estimated equations.Results:According to the regression equation,theδvalue of trigger threshold is 45 HU in 40 keV VMI.The optimal bolus-tracking trigger threshold=mean non-contrast vessel(HU)+45 HU.Conclusion:The optimal bolus-tracking trigger threshold in low contrast medium protocol using 40 keV VMI can be reduced by55 HU.

关 键 词：双能CT 虚拟单能谱影像 模体实验 触发阈值优化 

分 类 号：R4[医药卫生—临床医学]