16层螺旋CT在心房颤动射频消融术前的应用测量

Application of Multislice Spiral CT in Atrial Fibrillation before Radio frequency Catheter Ablation

目的研究心房颤动导管射频消融肺静脉电隔离术前左心房、肺静脉和食管16层螺旋CT成像技术及临床意义。资料与方法40例心房颤动患者在术前1-3天行多层螺旋CT（MSCT）检查,采用容积再现（VR）、多平面重组（MPR）及最大密度投影（MIP）等方法重组并测量各肺静脉口直径、左心房至肺静脉第一分支的距离、食管与左心房后壁接触的范围、食管壁厚度、左心房后壁厚度以及左心房与食管间的脂肪垫厚度。结果共显示肺静脉165支,右上肺静脉口前后径和上下径分别为（16.3±3.1）mm和（19.0±2.6）mm;右下肺静脉分别为（16.4±3.6）mm和（18.0±3.5）mm;左上肺静脉分别为（14.4±3.0）mm和（18.4±3.6）mm;左下肺静脉分别为（12.6±2.8）mm和（17.0±2.8）mm。食管与左心房后壁接触的平均长度为（56±12）mm,在双上、下肺静脉水平与左心房后壁接触的食管平均宽度分别为（10±5）mm和（14±5）mm。60%的食管位于左心房后壁中线偏左,大致与左上、下肺静脉口平行;40%的食管沿左上肺静脉向右下肺静脉斜行走行。左心房后壁和食管前壁的平均厚度分别为（2.2±0.8）mm和（3.5±1.6）mm。95%的左心房与食管间可见脂肪垫,其平均厚度为（0.8±0.2）mm。结论应用MSCT造影增强扫描可清楚显示各肺静脉口直径、分支特征、走行以及有无发育畸形,同时还能评价食管与左心房的关系,为心房颤动导管射频消融术的顺利实施提供重要解剖依据。

Objective To investigate the feasibility and clinical value of the visualization of pulmonary veins, the left atrium and the esophagus using 16-slice spiral computed tomography before radio-frequency （RF） catheter ablation in patients with atrial fibrillation （AF）. Materials and Methods A helical CT scanning of the chest with 3D reconstruction was performed in 40 patients （24 men, mean age, 60 years） with atrial fibrillation 1 to 3 days before an ablation procedure. PV ostia were measured in two directions （anterior-posterior and superior-inferior）. Consecutive axial and sagittal sections of the CT scanning were reformatted to determine the relationship, size and thickness of the tissue layers between the LA and the esophagus using VR, MIP and MPR. Results In 40 patients, a total number of 165 PV was observed. Average measurements of RSPV ostia in the anterior-posterior direction and the superior-inferior direction were （16.3 ± 3.1 ）ram and （ 19.0 ± 2.6）mm respectively, measurements of RIPV, LSPV and LIPV were （16.4±3.6）mm and （18.0±3.5）mm, （14.4±3.0）mm and （18.4±3.6）mm, （12.6±2.8）mm and （ 17.0 ± 2.8 ） mm, respectively. The mean length and width of the esophagus in contact with the posterior LA were （56 ± 12） mm. （10 ± 5）mm and （14 ± 5 ）mm, respectively. The esophagus had a variable course along the posterior LA. The esophagus was close and parallel to the left-sided pulmonary veins in 60% of patients and had an oblique course from the left superior PV to the right inferior PV in 40 % of patients. The mean thickness of the posterior LA and anterior esophageal wall was （2.2 ± 0.8 ）mm and （3.5 ± 1.6）mm, respectively. In 95% of patients, there was a fat layer between the esophagus and the posterior LA, its mean thickness was （0.8 ± 0.2）mm. Conclusion MSCT scanning is a safe, quick and noninvasive examination, which could demonstrate the anatomy of left atrial, esophagus and pulmonary veins, MSCT scanning can provide information for catheter ablation inatrial fibrillation sufferers.