256层iCT迭代重建技术低剂量扫描在颈部血管成像中的应用

Application of low-dose scanning with iterative reconstruction technique in 256-slice iCT angiography for cervical arteries

目的探讨256层iCT iDOSE迭代重建技术低剂量扫描在颈部血管CT血管造影(CTA)中的临床价值。方法选取2016年6月至2017年4月需行颈部血管CTA检查的64例患者,随机分为A、B两组,每组32例。A组采用iDOSE迭代重建技术及管电流100 mAs;B组采用滤波反投影重建算法及管电流250 mAs,其他参数两组均保持不变。采用独立t检验比较两组图像不同解剖位置的动脉强化CT值、有效辐射剂量以及图像质量主观评分。结果 A组主动脉弓、颈总动脉起始端、颈内动脉起始端血管内CT值分别为(364.61±57.65)HU、(400.09±65.83)HU、(337.35±54.29)HU,B组主动脉弓、颈总动脉、颈内动脉起始端血管内CT值分别为(372.76±56.83)HU、(393.28±64.94)HU、(336.06±61.84)HU;组间差异均无统计学意义(P均>0.05)。A、B组图像质量评分分别为(4.40±0.40)分、(4.10±0.30)分,A组显著高于B组(t=3.39,P<0.01);辐射剂量分别为(1.58±0.09)mSv、(7.60±0.88)mSv,A组显著低于B组(t=38.50,P<0.01)。结论采用iDOSE迭代重建技术低剂量扫描行颈部CTA检查,在满足临床诊断要求的前提下,既可提高图像质量又可有效降低辐射剂量。

Objective To explore the clinical value of low dose scanning in 256-slice iCT iterative reconstruction（iDOSE） in cervical computed tomography angiography（CTA）. Methods From June 2016 to April 2017,64 patients receiving CTA examination were randomly divided into group A and group B（n = 32,each）. In group A,iDOSE iterative reconstruction technique and tube current of 100 mAs was used,and filtered back projection reconstruction method and tube current of 250 m As was used in group B. The other parameters remained unchanged in two groups. By independent T test,enhanced CT value of arteries,effective radiation dose and subjective image quality score were compared at different anatomical positions between two groups. Results CT values of the aortic arch,the origin of common carotid artery and the origin of internal carotid artery were（364. 61 ± 57. 65） HU,（400. 09 ± 65. 83） HU,（337. 35 ± 54. 29） HU respectively in group A and were（372. 76 ± 56. 83） HU,（393. 28 ± 64. 94） HU,（336. 06 ± 61. 84） HU respectively in group B. There were no significant differences between two groups（all P 0. 05）. The image quality score in group A was significantly higher than that in group B [（4. 40 ± 0. 40） vs（4. 10 ± 0. 30）,t = 3. 39,P 0. 01]. The radiation dose in group A was significantly lower than that in group B [（1. 58 ± 0. 09） mSv vs（7. 60 ± 0. 88） mSv,t = 38. 50,P 0. 01]. Conclusion Under the premise of satisfying clinical diagnosis,iDOSE iterative reconstruction technique of low dose scanning can improve the image quality and reduce the radiation dose effectively in cervical CTA.