基于混合对比剂的纹理分析在低管电压CT冠状动脉成像中的应用研究

The application of texture analysis based on mixed contrast agent in CT coronary angiography with low tube voltage

目的通过图像纹理分析探讨混合对比剂在低管电压冠状动脉成像中的可行性。方法收集60例疑似冠心病患者行冠状动脉CTA检查,按随机数字表法等分为对照组和实验组各30例。对照组直接注射碘普罗胺(300mg/ml),使用常规120kV扫描,实验组注射混合对比剂,其浓度为使用双流技术按对比剂与生理盐水8:2实时配比为240mg/ml,使用100kV低管电压扫描。两组均使用迭代算法(AIDR 3D)重建图像。比较两组之间左冠状动脉主干、左前降支近段、左回旋支近段及右冠状动脉近段客观参数及主观图像质量评分,使用GE公司纹理分析软件比较两组升主动脉各纹理参数值,分析混合对比剂的均匀性。结果两组年龄、心率、管电流、体质指数(BMI)、体重均无统计学差异(P>0. 05),两组注射压力、总碘含量、辐射剂量(ED)有统计学差异(P <0. 05)。两组左前降支、左回旋支近段血管强化值及血管噪声值有统计学差异(P <0. 05)。两组冠状动脉血管近段SNR、CNR及平均质量得分无统计学意义(P> 0. 05)。两组升主动脉的纹理参数中偏度(skewness)、峰度(kurtosis)没有统计学差异(P> 0. 017),方差(Variance)、熵(Entropy)和能量(Energy)有统计学差异(P <0. 017)。结论通过纹理分析及质量评价验证了混合对比剂在低管电压冠状动脉CTA中的可行性,同时也能满足诊断需求。

Objective To investigate the feasibility of mixed contrast agent in low voltage coronary angiography by image texture analysis. Methods We collected 60 patients with suspected coronary artery disease, who were examined by CTA. The patients were randomly divided into control group and experimental group (n=30). The control group injected iopromide (300 mg/ml), with use of conventional 120 kV scanning, the experimental group was injected with mixed contrast agent, its concentration for the use of double contrast agent with saline by 8:2 real time ratio was 240 mg/ml, 100 kV using low tube voltage scanning. The two groups were reconstructed using iterative algorithm (AIDR 3D). The comparison was conducted between the two groups of left main coronary artery, proximal left anterior descending and left circumflex artery proximal right coronary artery and proximal objective parameters and subjective image quality score. Using GE texture analysis software, we compared the ascending aorta texture parameters between two groups, and analyzed the uniformity of the mixed contrast agent. Results There was no significant difference in age, heart rate, tube current, body mass index (BMI) and body weight ( P >0.05) between the two groups (ED). There was significant difference between the two groups in the injection pressure, total iodine content and radiation dose ( P <0.05). There were significant differences between the two groups in the left anterior descending branch and the left circumflex branch of vascular enhancement and vascular noise ( P <0.05). There was no significant difference in SNR, CNR and mean quality score between the two groups ( P >0.05). There was no significant difference in the skewness (skewness) and kurtosis (kurtosis) between the two groups of ascending aorta ( P >0.017), and the Variance, Entropy and Energy were statistically significant ( P <0.017).Conclusion The feasibility of mixed contrast agent in low voltage coronary artery CTA was verified by texture analysis and quality evaluation.