多层双源CT大螺距头颈心血管双期扫描在心率波动患者中应用的可行性研究

Feasibility study of the multi-slice dual-source CT double turbo flash mode for one-step coronary and carotid-cerebrovascular CT angiography in patients with heart rate variability

目的探讨多层双源CT大螺距头颈心血管双期扫描在心率波动患者中应用的可行性,并评价图像质量及辐射剂量。方法回顾性分析2017年1月至2019年11月河北省人民医院心率波动大于3次/min的79例患者。按照检查方案的不同将患者分为2组:A组(40例):注射1次对比剂,采用大螺距双期模式行头颈心CTA一站式扫描(第1期图像为Single A组,第1、2期结合图像为Double A组);B组(39例):注射2次对比剂,分别行头颈CTA减影扫描和冠状动脉CTA回顾性心电门控扫描。对图像资料进行主观评分,并测量CT值、噪声(SD)、信噪比(SNR)、对比噪声比(CNR)等客观评价指标,记录辐射剂量与对比剂用量。采用单因素方差分析比较3组图像的主观评分、客观评价指标及辐射剂量,采用独立样本t检验比较A组与B组对比剂用量。结果Single A组、Double A组和B组间的头颈CTA主观评分差异无统计学意义,均满足诊断需求;3组间的冠状动脉CTA主观评分差异有统计学意义(P<0.05),Single A组评分最低,Double A组和B组间差异无统计学意义(P=0.104),均满足诊断需求。Double A组为双期结合、择优评价图像。头颈CTA检查3组间CT值、SD值、SNR和CNR差异均有统计学意义(P均<0.05),其中Single A组与Double A组差异均无统计学意义,B组和Single A组、B组和Double A组的差异均有统计学意义(P均<0.05)。冠状动脉CTA检查3组间的CT值、SNR和CNR差异均有统计学意义(P均<0.05)。3组患者间的剂量长度乘积和有效剂量差异均有统计学意义(P均<0.05)。Double A组的有效剂量(2.66±0.92)mSv较B组(4.94±1.70)mSv降低46.15%。A组对比剂用量为(57.60±5.46)ml,较B组(103.10±3.17)ml降低44.13%,差异有统计学意义(t=-45.455,P<0.01)。结论多层双源CT大螺距双期扫描在心率波动患者的头颈心血管一站式成像中具有可行性,能以较低的辐射剂量与对比剂量获得满意的图像质量。

Objective To investigate the feasibility of one-step coronary and carotid-cerebrovascular computed tomography angiography(CTA)using high-pitch Double Turbo Flash mode and to analyze the image quality and radiation dose in patients with heart rate variability using multi-slice detector dual-source CT.Methods A total of 79 patients with heart rate variability higher than 3 beat/min(bpm)were retrospectively analyzed.They were grouped by the scanning methods.Group A(n=40)were performed double turbo flash mode for one-step coronary and carotid-cerebrovascular arteriesinjected with one injection of contrast agent.further divided into Single A(only the phase 1 image)and Double A(combined images of phases 1 and 2).Group B(n=39)were performed separately with twice injection of contrast agent.Subjective scoring was performed on the image quality of the group Single A,Double A and B using a 4-point.Then the objective parameters of image quality,CT attenuations,image noise,signal-to-noise(SNR),and contrast-to-noise(CNR),were evaluated.Then subjective scores,objective evaluation indicators,and radiation dose were compared with one-way ANOVA analysis among the three groups.Contrast agent were compared by using t test in group A and B.Results No significant difference was found(F=2.093,P=0.128)for the subjective scores of the head and neck CTA among the three groups with(3.47±0.51),(3.53±0.51),(3.69±0.47).Significant difference was found(F=50.955,P<0.01)for the subjective scores of coronary CTA among the three groups with(2.70±0.76),(3.35±0.66),(3.58±0.50),and there was no statistically significant difference between Double A and B groups(P=0.104),met the requirements for diagnosis.The objective evaluation of the three groups compared the head and neck CTA images were statistically significant(P<0.05),of which the difference between the Single A and the Double A was not statistically significant(P>0.05),met the requirements for diagnosis;the differences in SNR and CNR of coronary CTA images are statistically significant(F=12.991,12.236,P<0.01),and there was no statistically significant difference between Double A and B(P>0.05),met the requirements for diagnosis.Radiation dose in the group Double A was lower than group B(decreased by 46.15%,P<0.01).The amount of the contrast agent in the group Double A was lower than group B(decreased by 44.13%,t=-45.455;P<0.01).Conclusion The double turbo flash mode is feasibility for one-step coronary and carotid-cerebrovascular CTA in patients with the heart rate variability using multi-slice dual-source CT.This scan mode can maintain the diagnostic image quality with low contrast agent and radiation dose.