低浓度对比剂门静脉成像在能谱 CT 中的临床应用

医学研究与教育 ›› 2014, Vol. 31 ›› Issue (5): 22-28.

低浓度对比剂门静脉成像在能谱 CT 中的临床应用

赵永霞^1,3，常津²，左紫薇³，张畅达³，张天乐³

1. 天津大学精仪学院，天津 300000；2. 天津大学，天津 300000；3. 河北大学附属医院，河北保定 071000

出版日期:2014-10-25 发布日期:2014-10-25
通讯作者: 常津（1963—），男，河北石家庄人，教授，博士，博士生导师，主要从事生物医学工程研究。E-mail: jinchang@tju.edu.cn
作者简介:赵永霞（1974—），男，河北石家庄人，副主任技师，硕士，硕士生导师，主要从事医学影像成像参数的优化研究。
基金资助:
河北大学国家级大学生创新训练计划项目（201410075027）；河北大学研究生教育教学改革研究项目（YJ11-33）

The application with low concentration of contrast media and spectral CT imaging in the portal venography

ZHAO Yongxia¹, CHANG Jin² , ZUO Ziwei³ , ZHANG Changda³, ZHANG Tianle³

1. College of precision instrument and optoelectronic engineering of Tianjin University, Tianjin 300000,China;2. Tianjin University, Tianjin 300000, China; 3. Affiliated Hospital of Hebei University, Baoding 071000, China

Online:2014-10-25 Published:2014-10-25

摘要/Abstract

摘要： 目的探讨低浓度对比剂门静脉成像在能谱 CT中的临床应用。方法 50 例患者分为 5 组行肝脏门静脉期能谱 CT扫描，患者注射对比剂总量为 1 mL/kg，5 组患者注射对比剂浓度分别为 320 mgI/mL，288 mgI/mL，256 mgI/mL，224 mgI/mL，192 mgI/mL，扫描结束获得门静脉期 0.625 mm 层厚的门静脉最佳对比度噪声比（CNR）单能量图像，用此单能量图像对门静脉行 VR 和 MIP 重组。测量 5 组图像中门静脉和相同层面背部肌肉竖脊肌及腹壁脂肪的 CT 值及其标准差，计算信噪比（SNR）及 CNR 并取平均值，由 2 名高年资医师在盲法下对 5 组图像进行主观图像质量评分并取平均值，5 组间比较采用单因素方差分析（ANOVA）。2 名医师对重建图像质量一致性评估采用 Kappa 检验。结果门静脉最佳 CNR 单能量图像能量为 50~55 keV。5 组注射不同浓度对比剂患者的 SRN、CNR 分别为 15.83±3.02、14.78±2.13、13.87±1.91、9.37±2.13、7.72±2.82 和 14.95±3.82、15.01±3.79、13.93±3.52、10.35±4.22、9.65±3.56。2 位医师评分值均值为 4.50±0.81、 4.45±0.76、4.41±0.73、4.38±0.79、3.5±0.57。浓度为 320 mgI/mL、288 mgI/mL、256 mgI/mL 之间 SNR、CNR 及 2 位医师评分值之间差异无统计学意义（F=36.221，P<0.05）；320 mgI/mL、288 mgI/mL、256 mgI/mL 与 224 mgI/mL 、192 mgI/mL 之间SNR、CNR 及 3 位医师评分值之间差异有统计学意义（F=7.221，P>0.05）。2 名医师对 320 mgI/mL、288 mgI/mL、256 mgI/mL对比剂浓度产生图像质量评价的一致性（Kappa 值为 0.86）高于 224 mgI/mL、192 mgI/mL 对比剂浓度产生图像（Kappa 值为 0.63）。结论应用能谱 CT 最佳单能量门静脉成像能显著降低对比剂使用浓度，推荐使用对比剂浓度为 256 mgI/mL，注射总量为 1 mL/kg。推荐能谱 CT 显示门静脉的最佳单能量为 50～55 keV。

关键词: 低浓度对比剂, CT 门静脉成像, 影像质量, 比较研究

Abstract: Objective To investigate the effect of low concentration of contrast media with energy spectral CT on the image quality of CT portal venography. Methods 50 patients were divided into 5 groups underwent spectral CT examination on a GE Discovery CT 750 HD scanner, the total contrast media were offered at 1 mL/kg to 50 patients, the contrast media concentration of 320 mgI/mL, 288 mgI/mL, 256 mgI/mL, 224 mgI/mL, 192 mgI/mL were offered for the 5 groups patients. During portal phase, 0.625 mm slice thickness polychromatie images and optimal monochromatic images were obtained, and volume rendering and maximum intensity rojection were created to show the portal venography respectively, the CT unit and standard deviation were measured at the port venography and the erector muscle of spine, calculated the signal-noise ratio and the contrast-noise ratio, calculated the singal-noise ratio and contrast-noise ratio with the CT volue of port venography and the erector muscle of spine. The overall imaging quality was evaluated on a five-point scale by 3 radiologists, Comparisons between 5 groups were tested by One-Way ANOVA analysis.Results The monochromatic images at 50-55 keV were found to demonstrate the best CNR for both the portal vein and erector muscle of spine. The SNR with the different concentrations of contrast media was 15.83±3.02, 14.78±2.13, 13.87±1.91, 9.37±2.13, 7.72±2.82 and the CNR was 14.95±3.82, 15.01±3.79, 13.93±3.52, 10.35±4.22, 9.65±3.56. The values by three independent radiologists were 4.50±0.81, 4.45±0.76, 4.41±0.73, 4.38±0.79, 3.5±0.57. The dates of SNR , CNR and values were not statistically significant at the contrast media concentration of 320 mgI/mL, 288 mgI/mL, 256 mgI/mL, 224 mgI/mL(F=36.221, P<0.05). The dates of SNR, CNR and values were statistically significant at the contrast media concentration of 320 mgI/mL, 288 mgI/mL, 256 mgI/mL and 224 mgI/mL, 192 mgI/mL（F=7.221, P>0.05） . In the comparison of image quality, Kappa value was 0.86 with the contrast media concentration of 320 mgI/mL, 288 mgI/mL, 256 mgI/mL and 0.63 with 224 mgI/mL, 192 mgI/mL. Conclusion The best monochromatic images of spectral CT could reduce the contrast media concentration, Recommend concentration of the contrast media was 256 mgI/mL at portal venography by spectral CT imaging. The best monochromatic X-ray keV was 50-55 keV.

Key words: low concentration of contrast media, CT portal venography, image quality, comparative studies

中图分类号:

赵永霞，常津，左紫薇，张畅达，张天乐. 低浓度对比剂门静脉成像在能谱 CT 中的临床应用[J]. 医学研究与教育, 2014, 31(5): 22-28.

ZHAO Yongxia, CHANG Jin , ZUO Ziwei , ZHANG Changda, ZHANG Tianle. The application with low concentration of contrast media and spectral CT imaging in the portal venography[J]. Medical Reserch and Education, 2014, 31(5): 22-28.

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[2]	赵永霞,左紫薇. 能谱CT在消除硬化伪影中的应用[J]. 医学研究与教育, 2013, 30(6): 26-29.