低管电压、低浓度碘对比剂联合多模型迭代重建在心房颤动射频消融术前左心房和肺静脉CT成像中的应用价值

  目的  探讨低管电压、低浓度碘对比剂联合多模型迭代重建（ASIR-V）在心房颤动患者经导管射频消融术前左心房（LA）和肺静脉（PV）CT成像中的运用价值。  方法  回顾性分析2019年1月~2021年6月在遂宁市中心医院确诊经导管射频消融的所有心房颤动患者，并按管电压分为实验组（A组）和对照组（B组），143例/组。A组使用低管电压100 kVp，对比剂碘海醇300 mgI/mL，ASIR-V 10%~100%间隔10%重建；B组使用常规管电压120 kVp，对比剂碘帕醇370 mgI/mL，ASIR-V 50%重建。LA和PV图像质量客观评价采用信噪比和对比噪声比进行比较，主观评分采用双盲法以5分法评价。对患者一般临床资料、辐射剂量、碘摄入量、LA和PV解剖变异显示率及相关测量指标及图像质量进行评价。  结果  A、B两组比较，LA和PV的CT值、解剖变异显示率以及相关测量指标差异均无统计学意义（P > 0.05）。A组有效辐射剂量和碘摄入量分别较B组减少约37.4%、29.9%（P < 0.05）。随ASIR-V重建比例的增加，A组的SD值逐渐降低，而信噪比及对比噪声比逐渐升高（P < 0.05）；A组重建图像中，70%和80% ASIR-V的主观评分最高（P < 0.05）。  结论  低管电压（100 kVp）、低浓度碘对比剂（300 mgI/mL）联合70%或80% ASIR-V扫描方案可用于心房颤动患者经导管射频消融术前对LA和PV解剖及相关指标的评价，在保证图像质量的前提下，可显著降低电离辐射并减少碘剂摄入量。 

Application value of low tube voltage,low concentration iodine contrast agent combined with adaptive statistical iterative reconstruction-V technique in left atrium and pulmonary vein CT imaging before radiofrequency catheter ablation for atrial fibrillation

  Objective  To investigate the application value of low tube voltage, low concentration iodine contrast agent combined with adaptive statistical iterative reconstruction-V (ASIR-V) in CT imaging of left atrium (LA) and pulmonary vein (PV) in patients with atrial fibrillation before radiofrequency catheter ablation.  Methods  All atrial fibrillation patients diagnosed with radiofrequency catheter ablation in our Hospital from January 2019 to June 2021 were retrospectively analyzed. The patients were divided into experimental group (group A) and control group (group B) according to tube voltage, with 143 cases in each group. Group A used low tube voltage 100 kVp, contrast agent iohexol 300 mgI/mL, ASIR-V 10%-100% interval 10% reconstruction. Group B used conventional tube voltage 120 kVp, contrast agent iopamidol 370 mgI/mL, ASIR-V 50% reconstruction.The objective evaluation of LA and PV image quality was performed by comparing the signal-to-noise ratio and contrast-to-noise ratio, and the subjective score was evaluated by a double-blind method on a 5-point scale. The general clinical data, radiation dose, iodine intake, display rate of LA and PV anatomical variation, related measurement indexes and image quality were evaluated.  Results  There was no significant difference in CT value, anatomical variation display rate and related measurement indexes of LA and PV between groups A and B (P > 0.05). Compared with group B, the effective radiation dose and iodine intake of group A were decreased (P < 0.05). With the increase of ASIR-V reconstruction ratio, the SD value of group A gradually decreased, while the signal-to-noise ratio and contrast-to-noise ratio gradually increased (P < 0.05). In the reconstructed images of group A, the subjective scores of 70% and 80% ASIR-V were the highest (P < 0.05).  Conclusion  Low tube voltage (100 kVp), low concentration iodine contrast agent (300 mgI/mL) combined with 70% or 80% ASIR-V scanning scheme can be used to evaluate LA and PV anatomy and related indicators before radiofrequency catheter ablation in atrial fibrillation patients. Significant reductions in ionizing radiation and iodine intake can be achieved without sacrificing image quality.