肺恶性肿瘤氩氦刀治疗后的CT和MRI表现

目的评价肺恶性肿瘤氩氦刀治疗后的CT和MRI表现。方法收集并分析24例肺恶性肿瘤患者氩氦刀治疗前7天内及治疗后1天、7天、1个月、3个月、6个月、1年的CT和MRI表现。根据随访结果,将患者分为完全消融组(A组)和残留或复发组(B组)。结果治疗后1~7天的CT和MRI均表现为消融灶较治疗前增大,消融灶周围出现环形低密度/信号影,A组消融灶周围的环形影较B组完整。MRI显示消融灶周围环形影的清晰度优于CT。治疗后1~6个月,A组消融灶开始缩小,无明显强化;B组消融灶与治疗前相仿或稍增大,明显不均匀强化。治疗后6个月~1年,A组消融灶逐渐缩小;B组消融灶明显增大。结论肺恶性肿瘤氩氦刀治疗后CT和MRI表现有一定特征性,治疗后消融灶周围的环形低密度/信号影是评价肿瘤是否残留或复发的重要征象,且MRI对环形影的显示清晰度优于CT。

CT and MRI appearances of malignant lung tumors after Argon-Helium cryoablation therapy

Objective To evaluate the CT and MRI characteristics of malignant lung tumors after Argon-Helium cryoablation therapy. Methods Twenty-four malignant lung tumors patients received Argon-Helium cryoablation therapy were enrolled. All the patients underwent CT and MRI scans respectively before treatment and one day, one week, one month, three months, six months and one year after treatment. According to the follow-up results, patients were divided into the complete ablation group (group A) and the remnant or recurrence group (group B). Results From 1 to 7 days afer treatment, the lesion size became significantly larger compared with pre-treatment, and a hypointense rim surrounding the ablation zone were seen on both CT images and MRI. The hypointense rims in group A were complete, which were relatively incomplete in group B. The peripheral rims on MRI were clearer than that on CT images. From 1 to 6 months after treatment, the ablated lesion size in group A decreased without enhancement, while in group B, the lesion size increased with inhomogeneous enhancement. From 6-month to 1 year follow-up CT and MRI examination after treatment, the ablated lesion size in group A decreased gradually, while increased obviously in group B. Conclusion CT and MRI findings of the ablation zone in malignant lung tumors after Argon-Helium cryoablation therapy are characteristic, the hypointense rim surrounding ablation zone after treatment is a helpful sign to determine whether recurrence will occur later, and the rim is clearer on MRI than on CT.