摘要
目的：探讨能谱CT双低技术（低浓度对比剂、低管电压）对门脉期肝静脉血管成像质量的影响。方法：前瞻性收集2013年3—12月因怀疑腹部疾病来我院行全腹部能谱CT三期动态增强扫描BMI≤22 kg/m2的患者119例。随机分为高浓度对比剂常规扫描方案组（350 mgI/mL、120 kVp）即A组（41例），和低浓度对比剂低管电压加50% ASiR重建扫描方案组（270 mgI/mL、80 kVp）即B组（78例）。于门脉期由两名观察者独立测量肝静脉左、中、右支起始部及肝右后叶肝实质CT值、肝实质噪声值，组内一致性检验采用组内相关系数检验。记录每组图像的CTDIvol，计算CNR及FOM。对其分支血管进行MIP及VR重建，由两名分别具有8年和6年腹部影像诊断经验的医师采用双盲法对两组重建图像质量进行5分制主观评分。两名医师对重建图像质量评分一致性检验采用Kappa检验，两组图像质量评分采用Mann-Whitney U检验；两组门脉肝静脉左、中、右支CT值、肝实质CT值及噪声值、CNR值、CTDIvol值及FOM值采用两独立样本T检验。本研究经我院伦理委员会审批同意，所有患者检查前均签署知情同意书。结果：两名观察者对两组图像评分一致性良好，A组分别为0.808、0.852、0.851；B组肝静脉左、中、右支Kappa值分别为0.923、0.937、0.899，取年资高者评分进行Mann-Whitney U检验，肝静脉左支Z值为-0.402，P=0.688，差异无统计学意义，肝静脉中支Z值为-1.240，P=0.215，差异无统计学意义，肝静脉右支Z值为-0.094，P=0.925，差异无统计学意义。两组组内相关系数检验一致性良好，ICC值均＞0.75。B组肝静脉左、中、右支CT值、肝实质CT值及标准差均高于A组，差异有统计学意义。B组肝静脉左支CNR均值（4.708±2.118）小于A组（3.924±1.514），差异有统计学意义，P<0.05；B组肝静脉中支、右支CNR均值小于A组，但P＞0.05，差异无统计学意义。B组CTDIvol均值（5.509±1.346）小于A组（7.975±2.464），差异有统计学意义，P<0.05。B组肝静脉左支FOM均值（4.362±4.408）大于A组（2.303±1.851），差异有统计学意义，P<0.05；B组肝静脉中支FOM均值（5.226±5.972）大于A组（2.630±1.922），差异有统计学意义，P<0.05。B组肝静脉右支FOM均值（4.418±4.506）大于A组（2.710±1.740），差异有统计学意义，P<0.05。结论：能谱CT低浓度对比剂结合低管电压技术在肝静脉血管成像质量方面有良好的可行性。
Abstract
Objective: To investigate the feasibility of energy CT with low concentration of contrast media and low voltage for improving imaging quality of hepatic vein on hepatic venography. Materials and Methods: 119 patients with body mass index(BMI) lower than 22 kg/m2 who were suspicious of abdominal diseases were recruited in this prospective study and underwent tripple-phase enhanced CT scan of adbomen from March to December 2013 in our hospital. According to the scan time, the patients were randomly divided into two groups: group A(September to December 2013) with high concentration of contrast medium(350 mgI/mL) and routine tube voltage(120 kVp), including 41 cases(male 26 cases, female 15 cases, aged 59.20±11.69, group B(March to August 2013) with low concentration of contrast medium(270 mgI/mL) and low voltage(80 kVp), including 78 cases(male 55 cases, female 23 cases, aged 61.96±11.90). At portal phase, 1.25 mm-slice conventional images and optimal monochromatic images were obtained, and reconstruction was conducted by volume rendering(VR) and maximum intensity projection(MIP). The image quality of hepatic venography and the intrahepatic branches by MIP and VR was evaluated in a double-blind manner on a five-point scale by two radiologists with 8 years and 6 years of experience in abdominal diagnostic radiology. Two independent sample T-test was used to compare the CT value of hepatic veins and the liver parenchyma, the image noise, the vein-to-liver contrast-to-noise ratio(CNR) and the figure of merit(FOM) in the two groups. Inter-observer agreement was assessed by Kapppa value in image quality scoring. This study was approved by the institutional review board of our hospital. Results: The Kappa value of the image quality of left, middle and right hepatic veins by portal venography was good in group A(0.808, 0.852, 0.851, respectively) and group B(0.923, 0.937, 0.899, respectively). The CT values of the hepatic veins and liver parenchyma, image noise, CNR, FOM in group A were significantly lower than those in group B. Conclusion: Monochromatic images of energy CT with low concentration of contrast media and low voltage are feasibile for improving imaging quality of hepatic veins.
关键词
门静脉 /
体层摄影术 /
X线计算机
Key words
Portal vein /
Tomography /
X-ray computed
谢德舜;刘爱连;陈丽华;刘静红;张龙敏;佟梓滨;李 烨;吕婷婷;陈安良;刘义军;浦仁旺.
能谱CT低对比剂浓度与低管电压对肝静脉血管成像图像质量影响的研究[J]. 中国临床医学影像杂志. 2014, 25(11): 772-775
XIE De-shun;LIU Ai-lian;CHEN Li-hua;LIU Jing-hong;ZHANG Long-min;TONG Zi-bin;LI Ye;LV Ting-ting;CHEN An-liang;LIU Yi-jun;PU Ren-wang.
A preliminary study of improving imaging quality on hepatic venography with low voltage andlow concentration of contrast media by energy CT[J]. Journal of China Clinic Medical Imaging. 2014, 25(11): 772-775
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