摘要
目的对比观察64层CT管电流调制肺动脉成像(CTPA)中100kV与120kV的影像质量及辐射剂量。方法将61例临床怀疑肺栓塞患者随机分为2组,使用64层CT,分别以100kV(100kV组,31例)和120kV(120kV组,30例)管电压进行肺动脉成像,均使用管电流调制技术。测量肺动脉主干、双侧肺动脉、肺叶动脉、肺段及亚段肺动脉的CT值,以肺动脉主干CT值的标准差代表图像噪声。记录容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP)并计算有效剂量(ED),对两组上述指标进行t检验。使用4分法对图像质量进行主观评分,行Mann-WhitneyU检验。结果 100kV组肺动脉CT值均高于120kV组(P<0.05)。100kV组CTDIvol、DLP和ED均低于120kV组(P均<0.001)。两组图像噪声和主观评分差异无统计学意义(P均>0.05)。结论与120kV相比,100kV64层CT管电流调制CTPA动脉强化更好,ED更低,图像噪声和主观评分无显著差异。
Objective To compare the image quality and radiation dosage of 64-slice CT tube-current-modulation pulmonary angiography between 100 and 120 kV protocols. Methods Sixty-one patients suspected of pulmonary embolism underwent 64-slice CT pulmonary angiography with tube-current-modulation with 100 kV （100 kV group,n=31） and 120 kV （120 kV group,n=30） tube voltage. Attenuation （CT value） was measured in main pulmonary artery,left and right pulmonary arteries,lobar arteries,segmental arteries and subsegmental arteries. Image noise was quantified through measuring the standard deviation of attenuation in main pulmonary artery. Volume CT dose index （CTDIvol） and dose length product （DLP） were recorded and effective dose （ED） was calculated. CT value,image noise,CTDIvol,DLP and ED were compared by t test. Overall image quality was subjectively assessed with 4-score scale and compared by Mann-Whitney U test. Results Pulmonary arteries＇ attenuation in 100 kV group was significantly higher than that in 120 kV group （P0.05）. CTDIvol,DLP and ED were all lower in 100 kV group than those in 120 kV group （all P0.001）. No statistical difference was found in noise or subjective score （all P0.05）. Conclusion Compared with 120 kV protocol,100 kV protocol can significantly improve attenuation of pulmonary arteries and decrease radiation dosage,indicate that 100 kV protocol is valuable for clinical application of 64-slice CT tube-current-modulation pulmonary angiography.
出处
《中国医学影像技术》
CSCD
北大核心
2010年第10期1960-1963,共4页
Chinese Journal of Medical Imaging Technology
