基于SSF算法去除能谱CT图像运动伪影的研究

发布时间：2018-03-27 05:20

本文选题：冠状动脉血管　切入点：体层摄影术　出处：《新乡医学院》2017年硕士论文

【摘要】：背景冠状动脉CT血管成像(CCTA)在当今已经大范围地被运用于冠状动脉疾病的诊断与研究之中,在目前设备的时间及空间分辨率和成像图像重建算法在不断提高的大时代背景下,冠状动脉CTA图像成像的心动伪影依然存在着,对现行临床学诊断研究产生误差,这个是个比较棘手的问题确实存在着[1]。其中运动伪影的影响比心率影响更为显著,冠状动脉运动追踪技术(Snapshot freeze,SSF)是多层螺旋CT64排CT时代硬件及软件设备不断发展过程中所衍生成出来的新的产物,是心动运动的伪影图像后处理的计算机新重建算法,冠状动脉运动追踪技术SSF全面了相邻一个周期的心动图像信息资源来填补虚化的有断层的待观察的目标冠状动脉运动图像的轨迹,获得校正该目标血管运动成像的伪影,冻结冠状动脉的结果[2]。目的探讨能谱CT结合运动追踪冻结技术在冠状动脉CT血管成像(CCTA)65%时相下对不同CT值的图像去除运动伪影能力的研究,评价冠状动脉运动追踪技术(SSF算法)去除心动运动图像成像伪影后处理的临床应用价值与意义。方法选取30例患者,均进行最新一代宝石能谱前瞻性心电门控心脏多层螺旋CT(MSCT模式)扫描。平均年龄为56.3±11.4岁,男性13人,女性17人。按照CT值100,200,300,400,500HU分为A、B、C、D和E五组。对比剂注射流量标准为200mgI/kg,注射时流率为注射流量除以12秒。所有原始图像都重建65%的时相,加40%ASIR的迭代算法,均进行标准算法(STD)和冠状动脉运动追踪技术(SSF)两种方法重建。由2名医师分别对LM,LAD-p,LAD-m,LAD-d,D1,D2,LCX-p,LCX-m,LCX-d,LMB,RCA-p,RCA-m,RCA-d和PDA14个分支血管的标准算法(STD)和冠状动脉运动追踪技术(SSF)两种算法进行主观评分,采用5分制法。测量动脉主根部CT值和噪声同时测量心肌包脂肪CT值及噪声。计算信噪比(SNR)和对比噪声比(CNR),进行客观评价。采用单因素方差分析比较其客观性存在的差异;采用Wilcoxon检验比较两种算法主观性的差异。结果D组(CT值400HU)所得图像信噪比(SNR)和对比噪声比(CNR)分别为16.8±25,21.9±3.2,明显高于其他四组。在14支分血管的标准算法(STD)主观评分均低于冠状动脉运动追踪技术(SSF算法),p0.05有差异性存在且具有统计学意义。在D组(CT值400HU),LM,LAD-p,LAD-m,LAD-d,D1,D2,LCX-p,LCX-m,LCX-d,LMB,RCA-p,RCA-m,RCA-d,和PDA的冠状动脉运动追踪技术(SSF)组的主观评分方面分别为(4.8±0.4,4.8±0.4,4.5±0.5,4.2±0.6,3.7±0.7,4.3±0.5,4.4±0.6,4.3±0.7,3.8±1,4.1±0.8,4.5±0.6,4.1±1,4.3±0.7,4.3±0.5),标准算法(STD)组分别为(4.7±0.4,4.6±0.6,4.4±0.5,3.8±0.7,3.3±1,3.9±0.7,4.1±0.7,3.8±1,3.4±1,3.9±0.9,3.7±0.9,2±1,3.5±1,4.2±0.2)。结论在65%重建时相下,能谱CT结合冠状动脉运动追踪技术(SSF算法)对冠状动脉CT血管成像的图像质量有明显的改善,最佳CT值为400HU。
[Abstract]:Background Coronary artery CT angiography (CCTAA) has been widely used in the diagnosis and research of coronary artery disease. Under the background of the time and spatial resolution of the equipment and the improvement of image reconstruction algorithm, CCTAs have been widely used in the diagnosis and research of coronary artery disease. The artifact of coronary artery CTA image still exists, and the error in the current clinical diagnosis research is quite difficult. [1] the effect of motion artifact is more significant than that of heart rate. The coronary artery motion tracking technique (Snapshot freezeFs) is a new product derived from the continuous development of hardware and software equipment in the era of multi-slice spiral CT64 slice CT, and is a new reconstruction algorithm for the post-processing of the artifact image of cardiac motion. The coronary artery motion tracking technique (SSF) provides a comprehensive information resource of the adjacent cycle of cardiac images to fill up the track of the phantom target coronary artery motion image with a fault to be observed, and obtain the artifact to correct the target vessel motion imaging. Objective to investigate the effect of energy dispersive CT (EDS) combined with motion tracking freezing technique on the removal of motion artifacts from different CT images at 65 hours after coronary CT angiography (CCTA). To evaluate the clinical application value and significance of coronary artery motion tracking technique (SSF algorithm) in removing artifact processing of cardiac motion image. Methods Thirty patients were selected. All patients were scanned with the latest generation of electrocardiogram (ECG) multilayer spiral CT(MSCT mode. The mean age was 56.3 卤11.4 years old, 13 males, 13 males, and 56.3 卤11.4 years old. 17 women were divided into five groups according to CT value 100200300400500HU. The standard of contrast medium injection flow was 200 mg I / kg, the flow rate at injection time was injection flow rate divided by 12 seconds. All the original images were reconstructed 65% of the time phase, and the iterative algorithm of 40%ASIR was added. Two methods, standard algorithm STD) and coronary artery tracking technique (SSF), were used to reconstruct the two methods. The two methods were evaluated by two physicians, namely, LML-LAD-pLAD-LAD-mAD-LAD-D _ 1D _ 2LCX-pCX _ (LX) LCX-dLMBN RCA-mRCA-d and the standard algorithm of RCA-mRCA-mRCA-d for each branch of PDA14, and the coronary artery tracking technique (SSF), respectively, for the purpose of subjective evaluation of the two algorithms, the two methods were used to evaluate the RCA-mRCA-d and the coronary artery tracking technique (SSF), respectively. The CT value of arterial root and noise were measured simultaneously, the SNR and the contrast noise ratio (CNRR) were calculated, and the objective evaluation was carried out. The objective difference was compared by single factor analysis of variance (ANOVA). Results the signal-to-noise ratio (SNR) and contrast noise ratio (RRR) of D group were 16.8 卤251.90 卤3.2, respectively, which were significantly higher than those of the other four groups. The subjective scores of the standard algorithm for 14 branches of blood vessels were all higher than that of the other four groups. In group D, there was a significant difference between the two groups (P < 0.05). In group D, the subjective score of RCA-pRCA-mRCA-mRCA-d0. 5 in group D was 4.8 卤0. 44.8 卤0. 44.5 卤0. 54.5 卤0. 64.43 卤0. 64.3 卤0. 64.3 卤0. 64.3 卤0. 64.3 卤0. 64.1 卤0. 74.1 卤0. 84.1 卤0. 64.1 卤0. 64.1 卤0. 64.1 卤0. 64.1 卤0. 74.3 卤0. 74.3 卤0. 74.3 卤0. 74.3 卤0. 74.3 卤0. 74.3 卤0. 74.3 卤0. 74.3 卤0. 74.30 卤0. 74.30 卤0. 64.30 卤0. 64.40 卤0. 64.30 卤0. 64.40 卤0. 64.40 卤0. 54.40 卤0. 44.5 卤0. 44.5 卤0. 44.5 卤0. 44.5 卤0. 64.40 卤0. 64.40 卤0. 64.30 卤0. 64.43 卤0. 64.30 卤0. 64.34 卤0. 54.@@. 4. 7 卤0. 4, 4. 6 卤0. 6N, 4. 4 卤0. 5, 3. 8 卤0. 7, 3. 3 卤0. 7, 3. 3 卤13. 9 卤0. 7, 4. 8 卤1. 4 卤1. 4 卤1. 4 卤1. 9 卤1. 9 卤0. 9 卤0. 9 卤0. 9 卤1. 9 卤1. 5 卤1. 2 卤2. 2 卤1. 5 卤1. 2 卤0. 2. Conclusion under 65% reconstruction phase, Energy dispersive CT (EDCT) combined with coronary motion tracking (SSF) improved the image quality of coronary artery CT angiography. The best CT value was 400HU.
【学位授予单位】：新乡医学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R816.2

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