能谱CT对提高消化道出血图像质量的实验研究  

Experimental study of spectral CT imaging in the improvement of image quality in gastrointestinal bleeding

作　　者：王梓[1] 胡杉[1] 孟晓岩[1] 王艳春[1] 王秋霞[1] 汤浩[1] 李建军[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院放射科,武汉430030

出　　处：《放射学实践》2014年第10期1143-1146,共4页Radiologic Practice

基　　金：国家自然科学基金(81271528);国家自然科学基金(81371524)

摘　　要：目的:通过模型试验对能谱CT显示消化道出血图像的情况进行分析。方法:取一装有适量清水的透X线的方形塑料容器模拟肠腔。将对比剂稀释至3%浓度以模拟高压注射器3mL/s的注射流率状态,通过连接有3F微导管的微量注射泵以7种不同流率(0.00、0.05、0.1、0.2、0.3、0.4、0.5mL/min)注入水中模拟不同流率出血量。上述每种条件均通过双能CT(GE discovery CT750HD)进行能谱模式扫描。所有图像按单能及混能模式重建后传送至ADW4.5工作站。在出血区域和清水区域分设感兴趣区,经GSI软件后处理得到最佳对比噪声比单能图像(60keV)。分别对60keV单能图像以及140kVp混能图像的CNR值进行测量并使用配对样本T检验进行统计学分析。3位对本实验过程未知的具有10年工作经历以上的腹部影像诊断学医师对所有图像(以随机的顺序)中的出血情况进行主观评估。结果:与140kVp混能图像相比,60keV单能图像的CNR值在不同模拟出血量以及不同期相(3%,0.5mL/min,1.45:1in AP,1.35:1in PP;0.4mL/min,1.50:1in AP,1.18:1in PP;0.3mL/min,1.44:1in AP,1.11:1in PP;0.2mL/min,1.26:1in AP,1.37:1in PP;0.1mL/min,1.16:1in AP,1.26:1in PP;0.05mL/min,1.34:1in AP,1.17:1in PP)均有所提高。3名放射医师在60keV单能图像上均对7种模拟出血情况进行了准确的诊断,而在对混能图像的评估中,3名医师均未发现0.05mL/min条件下的出血征象。结论:与140kVp混能图像相比,60keV单能图像在不同流率、不同期相时均能提供具有更佳信噪比的显示出血情况的图像。60keV图像能提高CT诊断微量出血情况的能力。Objective：To analyze the image quality of spectral CT imaging in demonstrating bowel bleeding using an experimental model.Methods：The experimental model consisted of a plastic container filled with water to imitate bowel. Contrast agent was diluted to the concentration as 3% which simulated to the attenuation of bleeding.An injection rate of 3mL/s was used via a 3F-microcatheter with different flow rates （0.00、0.05,0.10,0.20,0.30,0.40,0.50mL/min）to imi-tate various volute of bowel bleeding.Spectral CT imaging were performed with dual energy CT （GE discovery CT 750HD） in all of the above-mentioned situation.All of the data acquired were transferred to AW 4.5 work station and reconstructed according to mono-and mixed-energy model.ROIs were set at the simulated bleeding areas and water area respectively.After GSI software post-processing,the monochromatic images with the most optimal contrast-to-noise ratio （CNR）were ob-tained at 60keV.The CNR values of monochromatic images acquired at 60keV and conventional polychromatic images ac-quired at 140kVp were measured and analyzed using paired sample T test.3 senior radiologists with more than 10y＇s experi-ence of abdominal imaging subjectively studied the images randomly,to evaluate the condition of bleeding.Results：Com-pared with that of 140kVp polychromatic images,the monochromatic images at 60keV were found to provide the better CNR in different injection rates and different phases of bleeding （3%,0.5mL/min,1.45：1 in AP,1.35：1 in PP;0.4mL/min, 1.50：1 in AP,1.18：1 in PP;0.3mL/min,1.44：1 in AP,1.11：1 in PP;0.2mL/min,1.26：1 in AP,1.37：1 in PP;0.1mL/min,1.16：1 in AP,1.26：1 in PP;0.05mL/min,1.34：1 in AP,1.17：1 in PP,P 〈0.001 for all）.7 types of simulated bowel bleeding were correctly diagnosed by the 3 radiologists on 60keV images.Whereas,all of the 3 radiologists could not find out bleeding at the condition of 0.05mL/min injection rate on polychromatic images.Conclusion：60keV monochromatic images provide better CNR tha

关 键 词：消化系统疾病 图像处理 计算机辅助 体层摄影术 X 线计算机 

分 类 号：R816.5[医药卫生—放射医学]