鼻窦低剂量螺旋CT扫描的应用价值探讨

Investigation of applications value of low dose spiral CT scanning in accessory nasal cavity

目的探讨低剂量螺旋CT扫描鼻窦的影像效果及其对鼻窦疾病的诊断价值。方法将60例行鼻窦CT扫描的患者分为A组、B组及C组,每组20人,A组采用200 mAs曝光,B组采用100 mAs曝光,C组采用50 mAs曝光,其余参数相同,重建图像后分别对不同体位的图像质量及不同组别的扫描剂量加权指数(CTDIw)进行比较。结果A组、B组及C组均能清晰显示重要结构,三组图像在水平位、冠状位及矢状位评分差异无统计学意义(P>0.05);B组及C组软组织窗及骨窗噪声均高于A组,C组骨窗及噪声高于B组,B组及C组的CTDIw值低于A组,C组的CTDIw值低于B组,差异均有统计学意义(均P<0.05)。结论 50 mAs螺旋扫描鼻窦可以替代常规剂量的CT扫描,在水平位、冠状位及矢状位能够取得满意的图像质量。

Objective To investigate the image quality and diagnosis value of low dose spiral CT scanning in accessory nasal cavity disease.Methods 60 cases of patients with CT scanning in accessory nasal cavity were divided into group A,group B and group C with 20 cases in each group,the patients in group A were treated with 200 mAs,the patients in group B were treated with 100 mAs,the patients in group C were treated with 50 mAs,other parameter was found no difference.After the image reconstruction,image quality were contrasted among group A,group B and group C in different body posture,and CT dosis weighing indexing（CTDIw） were compared among group A,group B and group C.Results Limpid image could be displayed in group A,group B and group C,the differences of scores of image quality in anteroposterior axes direction,coronal direction and horizontal direction among group A,group B and group C were not statistically significant（P 0.05）.Image noises in soft tissue window and bone window were higher in group B and group C than those in group A,image noise in bone window in group C was higher than that in group B,CTDIw in group B and group C were lower than those in group A,CTDIw was lower in group C than that in group B,the differences were all statistically significant（all P 0.05）.Conclusion CT scanning with 50 mAs in accessory nasal cavity can take the place of common CT scanning and obtain satisfactory image in anteroposterior axes direction,coronal direction and horizontall direction.