肝癌化疗栓塞术前肝动脉能谱CT成像中最佳单能量的选择

The selection of monochromatic images in the post process of hepatic arterial CT angiology before TACE

目的探讨选择最佳对比信噪比(CNR)获得最理想keV单能量图像质量以指导肝癌肝动脉化疗栓塞术的价值。方法收集我院2011年10月至2012年10月临床诊断无手术切除指征的肝细胞癌患者96例(其中男52例,女44例),采用GE Discovaery750HDCT扫描,范围从膈顶至双肾下极。图像后处理采用ADW4.4工作站和GSI-view软件,在单能量轴位图像上测量最佳CNR,并从101个单能量序列中选择满足最佳CNR的单能量序列。分别在QC图像、系统默认keV以及利用最佳CNR所得到的keV单能量图像上,测量肝固有动脉和肝右动脉的对比度和噪声值,由2位长期从事腹部影像工作的副主任医师分别对利用最佳CNR所获得的单能量图像、QC图像以及系统默认选择的单能量图像的轴位图像和MPR、VR图像质量进行评分,以评估利用最佳CNR进行后处理的价值。采用Stata10.0软件进行统计学处理,P<0.05为差异具有统计学意义。结果利用最佳CNR所得到的keV单能量图像的得分(4.78±0.44)明显高于其他两种方法所得到的图像,系统默认keV图像的得分(4.22±0.68)高于QC图像的得分(3.56±0.53),结果具有统计学意义(P<0.05)。与其他两种方法比较,利用最佳CNR得到的keV单能量图像中肝动脉的对比度高于其他两种方法,但图像噪声也较前述方法高(P<0.05)。结论利用最佳CNR技术选取一个最佳的keV单能量图像,可获得肝动脉和周围组织最佳的对比度,使肝脏动脉显示得更加清晰,从而更有效地指导无手术切除指征的肝癌肝动脉化疗栓塞术。

Objective To investigate the value of using optimal contrast noise ratio to select one optimal keV monochromatic images to improve image quality of hepatic arterial CT angiology before transcatheter arterial chemoembolization.Methods 96 patients with hepatic malignant tumors were underwent spectral CT examination from October 2011 to October 2012.There were 52 males and 44 females with ages ranging from 51 to 62 years（mean age of 57.61 years）.Using GE ADW 4.4 and GSI view software to post process the images and measure optimal CNR in transverse image to select an optimal keV monochromatic images.Measure contrast and noise of proper hepatic artery and the right hepatic artery in QC images,predefine keV monochromatic images selected by system and monochromatic images select by using optimal contrast noise ratio.Two radiologists major in abdominal and vascular radiology evaluate those images using score 1-5.Statistical analysis was carried out using the Stata version 10.0 software.P ＜ 0.05 was defined as statistical significance.Results The score,contrast and noise of monochromatic images select by using optimal contrast noise ratio was significantly higher than other two methods,and those of monochromatic images selected by system was significantly higher than QC images（P ＜0.05）.Conclusions Using optimal contrast noise ratio to select one keV monochromatic images set will enhance contrast between hepatic arteries and surrounding tissue,make arteries more visible and improve image quality of hepatic arterial CT angiology.