低碘含量对比剂联合低管电压及迭代重建在颈部增强CT检查中的应用

Low concentration contrast medium on neck enhanced examination by a combination of low-tube-voltage and iterative reconstruction technique

目的探讨低碘含量对比剂联合应用低管电压及迭代重建算法在颈部增强CT检查中的应用。方法 60例拟行颈部CT增强的患者随机分为3组:A组管电压100 k Vp,对比剂碘海醇(350 mg I/ml);B组80 kVp,碘克沙醇(270 mg I/ml);C组70 kVp,碘克沙醇(270 mg I/ml)。B、C两组并联合使用基于原始数据迭代重建算法SAFIRE。对图像质量进行主观及客观评价;并对3组中有明确病理学结果的病例进行符合率分析。图像质量、辐射剂量进行组间统计分析。结果在图像客观质量评价各指标中,C组血管CT值(446.958±82.885)Hu最高(P<0.001);而B组(14.520±6.421)Hu、C组(17.422±5.158)Hu的噪声低于A组(27.910±12.305)Hu,且B组、C组SNR与CNR较之A组明显提高(P<0.001);有效辐射剂量最小的为C组(1.427±0.276)m Sv。主观图像质量评价显示3组病例图像均可满足诊断需求,且B组、C组病理诊断符合率均不低于A组。结论采用低管电压(70 k Vp)、低碘含量对比剂(270 mg I/ml),并联合使用基于原始数据迭代重建算法SAFIRE进行颈部CT增强检查,既可有效降低辐射剂量,所得图像质量也可满足诊断要求。

Objective To assess the effectiveness and feasibility of neck enhanced CT with low-concentration contrast medium and low-tube-voltage combined with sinogram-affirmed iterative reconstruction(SAFIRE).Methods60patients underwent neck enhanced CT examination,were randomly divided into three groups:patients in group A received a conventional scan with100kVp and contrast media of350mgI/ml.Group B with80kVp and contrast media of270mgI/ml.Group C with70kVp and contrast media of270mgI/ml.SAFIRE were used in Group B and C.CT attenuation of carotid artery and other anatomical regions were measured.Image quality and radiation dose were compared.The diagnostic results were compared with pathological results to evaluate diagnostic accuracy.Results Objective image quality evaluation:the CT value of group C(446.958±82.885)Hu was the highest(P<0.001),The noise of group B(14.520±6.421)Hu and group C(17.422±5.158)Hu were lower than group A(27.910±12.305)Hu(P<0.001),and the signal to noise ratio(SNR)and contrast to noise ratio(CNR)of group B and group C were significantly higher than group A(P<0.001).Subjective image quality evaluation showed that all the images of three groups achieved diagnostic standards.Compared with group A and group B,the effective dose(ED)of group C was the lowest(P<0.001).Conclusion Combined SAFIRE with low concentration contrast medium of270mgI/ml and low-tube-voltage of70kVp on neck enhanced CT scanning can significantly reduce the radiation dose without impairing the image quality.