| Objectives The aim of this study was to provide technical support for image measurement of preoperative evaluation and postoperative comparative reexamination in atrial fibrillation ablation through comparing the difference of diameter at the entrance of pulmonary vein measured by different post-processing methods in 320-slice spiral CT imaging.Methods A total of 105 subjects(58 males and 47 females),with an average age of 58 years,underwent pulmonary vein and left atrial angiography with 320-slice spiral CT scanning before atrial fibrillation ablation in the Department of Radiology at the Affiliated Hospital of Chengde Medical College from January 2018 to March 2019 were included in this study.During subsequent atrial fibrillation ablation,selective pulmonary venography(CPV)was performed to measure the inlet diameter of each branch of the pulmonary vein,and the data were used as the control group.The 320-slice spiral CT was performed for subjects who underwent pulmonary vein and left atrial angiography.Patients with positive for contrast sensitivity testing,patients with new dysfunction in the decompensated period,patients with severe cardiac and renal insufficiency(creatinine level > 10 ?mol/L)and patients with poor breath holding during breathing training were excluded before the examination.All patients signed informed consent before the examination.If pulmonary venous variation was detected after successful examination,the patient should also be excluded.Before left atrial angiography of pulmonary vein was performed in all patients,it was necessary to have at least 6 hours on an empty stomach for subjects,then the venous access was established and indwelling trocar in anterior cubital vein was placed.The weight of the subject was routinely measured to accurately measure the dosage of contrast agent,and electrocardiography was performed for the patient.The examinee should take the supine position.The scan was performed from the foot to the head.The electrodes should be connected correctly according to the standard position before scanning and confirmed that the ECG signal had been received.And then breathing training for the patient was performed to maximize the inhibition of respiratory movement caused by artifacts,so that the patient could cooperate with the examination.The whole cardiac cycle volume scanning data set was collected,and the images were uploaded to the post-processing workstation.Multiplanar reconstruction(MPR),3Dvolume representation(VR),maximum density projection(MIP),virtual endoscopy(VE),and other post-processing techniques were used to reconstruct the image.The image showed the long axis image of the left atrium and pulmonary vein,which required the pulmonary vein trunk to be displayed completely.The maximum diameter of the pulmonary vein entrance was measured from the transitional point of the connection between the pulmonary vein and the left atrium,and the pulmonary vein with four independent openings in the pulmonary vein was used as the effective data.Patients undergoing atrial fibrillation ablation should be those who diagnosed as atrial fibrillation and the administration of antiarrhythmic drugs was ineffective.Patients with severe cardiac insufficiency,untreated valvular disease,pulmonary hypertension,abnormal coagulation function,severe hyperthyroidism and multiple organ failure of liver and kidney were excluded before the operation.The routine examination was improved.Multi-slice computed tomography(MSCT)was used to understood the anatomic structure of the pulmonary vein and left atrium.Patients with left atrial thrombosis were excluded.All patients signed informed consent and operation agreement.The patient underwent angiography in the supine position.The patient's heart should be located in the center of the ball tube in the C-arm machine.During angiography,the patient's left arm was held up and local anesthesia was performed.Left femoral vein and left subclavian vein were punctured,and mapping catheters were placed into the coronary sinus and right ventricle respectively.The atrial septum puncture needle was inserted through the left femoral vein catheter,and the contrast agent was sprayed after penetrating the atrial septum,showing that the left atrial image was successfully punctured(100 unit/kg of heparin was injected after completing the atrial septum puncture,and 1000 unit/hour of heparin was added during the operation to prevent thrombosis).The catheter was inserted through the femoral vein,pointing to the target vein.After fully exhausting,the highpressure syringe was connected,injecting 1.2 mL/kg of contrast agent.The C-arm rotating contrast mode was selected,and the tube ball was placed in the starting position.The delayed acquisition time was 0.When the high-pressure syringe triggered the linkage injection of contrast agent,the image was rotationally generated using the patient as the center at the speed of 30 frames per second,and the rotation time was 4 to 5 seconds.At the same time,right ventricular pacing(200 beats/min)was performed to reduce the excretion of contrast agent into the ventricle so as to increase the filling density ofcontrast agent in the left atrium and ensure that the left atrium and pulmonary vein were fully developed.The data collected during the operation were post-processed by Insplace software.For the reconstruction image,the diameter of the pulmonary vein entrance was measured by Leonardo image post-processing software.Results Among 105 samples,88 cases had normal pulmonary veins and 17 cases were excluded variant pulmonary veins.The entrance diameters of the right superior pulmonary vein,right inferior pulmonary vein,left superior pulmonary vein and left inferior pulmonary vein measured by the axial images were 20.42 ± 4.76 mm,18.11 ± 3.41 mm,19.93 ± 4.18 mm and 16.77 ± 3.43 mm,respectively.The entrance diameters of the right superior pulmonary vein,right inferior pulmonary vein,left superior pulmonary vein and left inferior pulmonary vein measured by VR were 21.25 ± 4.48 mm,4.48 mm,18.82 ±3.44 mm,21.58 ± 3.89 mm and 18.23 ± 3.34 mm,respectively.The entrance diameters of the right superior pulmonary vein,right inferior pulmonary vein,left superior pulmonary vein and left inferior pulmonary vein measured by MIP were 21.59 ± 4.39 mm,19.14 ±3.48 mm,21.94 ± 3.91 mm,21.94 ± 3.91 mm and 18.60 ± 3.38 mm,respectively.The entrance diameters of the right superior pulmonary vein,right inferior pulmonary vein,left superior pulmonary vein and left inferior pulmonary vein measured by MPR were 21.18 ±3.80 mm,19.07 ± 3.27 mm,21.63 ± 3.79 mm and 19.12 ± 3.90 mm,respectively.The entrance diameters of the right superior pulmonary vein,right inferior pulmonary vein,left superior pulmonary vein and left inferior pulmonary vein measured by VE were 21.40 ±4.52 mm,19.23 ± 3.18 mm,21.19 ± 4.13 mm and 18.01 ± 3.39 mm,respectively.The entrance diameters of the right superior pulmonary vein,right inferior pulmonary vein,left superior pulmonary vein and left inferior pulmonary vein measured by CPV were 21.19 ±4.10 mm,18.85 ± 2.94 mm,21.75 ± 3.38 mm and 18.06 ± 3.28 mm,respectively.SPSS Statistics 19.0 was used to analyze the data.One-way analysis of variance was used for comparison between groups,and t-test was used for pairwise comparison.P < 0.05 was considered to be a statistically significant difference.There was no significant difference between the data measured by CPV and the results obtained by transverse axial position,MPR,MIP,VR and VE(P > 0.05).Conclusions Multiple post-processing techniques of MSCT can accurately measure the diameter of pulmonary vein entrance,which are consistent and universal methods.Figure12;Table5;Reference 136... |
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