Association between reperfusion and shrinkage percentage of the aneurysmal sac after embolization of pulmonary arteriovenous malformation: Evaluation based on contrast-enhanced thin-section CT images

Purpose: To investigate an association between reperfusion and the percentage of shrinkage of the aneurysmal sac after embolization of pulmonary arteriovenous malformation (PAVM) and to determine the cutoff value of the shrinkage percentage for indicating reperfusion. Materials and methods: Twenty-two PAVMs with completely embolized feeding arteries with coils were examined. The percentage of sac shrinkage and the presence of reperfusion were evaluated on computed tomography before and 1, 3, and 12 months after embolization. The percentages of sac shrinkage were compared between the occlusion and reperfusion groups. The receiver-operating characteristic (ROC) curve was generated to determine the diagnostic efficiency of reperfusion of PAVM by using shrinkage percentages. Results: Reperfusion was seen in 14, 13, and 11 lesions at 1, 3, and 12 months, respectively. The mean percentage of sac shrinkage was significantly different between the two groups at 3 and 12 months. The area under the ROC curve was 0.991 at 3 months and 0.934 at 12 months. All 9 lesions with <60 % sac shrinkage at 12 months showed reperfusion. Conclusion: The percentage of sac shrinkage was closely associated with reperfusion after embolization of PAVMs at 3 and 12 months. A shrinkage percentage of <60 % at 12 months indicated reperfusion.