宽体探测器非门控心脑联合CT血管成像的可行性

Feasibility of Free Breathing,Non-Gated Heart to Brain CTA Using Wide Detector CT

目的探讨应用宽体探测器CT行自由呼吸、非门控心脑联合CT血管成像(CTA)的可行性。资料与方法招募具有心脑血管疾病危险因素志愿者24例纳入研究组,采用宽体探测器CT(GE revolution CT)行自由呼吸、非门控心脑血管联合扫描。同期纳入行心电门控宽体探测器冠状动脉CTA患者21例作为对照。分别测量所有研究对象升主动脉根部平均CT值、对比噪声比(CNR)及各心腔的平均CT值。采用4分法行冠状动脉节段评分评估两组冠状动脉成像图像质量;计算两组辐射剂量。结果研究组与对照组冠状动脉主观图像质量评分(3.10±0.79对3.28±0.71;Z=1.366,P>0.05)、升主动脉CT值[(502.25±115.02)Hu对(464.68±93.86)Hu;t=1.19,P>0.05]及CNR(21.68±6.14对24.81±6.86;t=1.613,P>0.05)差异均无统计学意义。研究组升主动脉噪声以及左心房、右心房、右心室平均CT值大于对照组,差异有统计学意义[23.71±3.21对19.62±4.73,t=3.438,P<0.05;(515.06±105.31)Hu对(429.98±108.00)Hu,t=2.672,P<0.05;(397.39±229.50)Hu对(137.55±33.67)Hu,t=5.480,P<0.05;(436.10±200.36)Hu对(152.52±49.11)Hu,t=6.707,P<0.05]。冠状动脉有效辐射剂量差异无统计学意义[(2.63±0.96)mSv对(2.83±0.97)mSv,P>0.05]。结论宽体探测器CT自由呼吸、非门控心脑联合CTA具有可行性,并可提供良好的图像质量用于心脑血管联合评估。

Purpose To evaluate the feasibility of free breathing,non-gated heart to brain CTA using a 16 cm detector CT.Materials and Methods Twenty-four volunteers with risks of cardiovascular and cerebrovascular diseases(study group)were recruited consecutively for non-gated heart-brain CTA under free breathing on a detector CT scanner(GE revolution).Another group of 21 patients who received ECG-gated coronary CTA served as controls(control group).The mean CT attenuation and contrast to noise ratio(CNR)of ascending aorta were measured,as well as the mean CT attenuation of cardiac chambers.Coronary artery image quality was rated using a four-point ordinal scale.The effective coronary CTA radiation doses of two groups was calculated.Results There was no difference in image quality scores of coronary artery segments between study group and control group(3.10±0.79 vs.3.28±0.71;Z=1.366,P>0.05).The mean CT attenuation and CNR of the ascending aorta showed no statistical difference between two groups[(502.25±115.02)Hu vs.(464.68±93.86)Hu;t=1.19,P>0.05.21.68±6.14 vs.24.81±6.86;t=1.613,P>0.05].The image noise of the ascending aorta and the mean CT attenuation of LA,RA and RV in study group were greater than those in control group[23.71±3.21 vs.19.62±4.73,t=3.438,P<0.05;(515.06±105.31)Hu vs.(429.98±108.00)Hu,t=2.672,P<0.05;(397.39±229.50)Hu vs.(137.55±33.67)Hu,t=5.480,P<0.05;(436.10±200.36)Hu vs.(152.52±49.11)Hu,t=6.707,P<0.05].There was no difference in effective radiation doses of coronary CTA between the two groups[(2.63±0.96)mSv vs.(2.83±0.97)mSv,P>0.05].Conclusion It is feasible to perform free breathing,non-gated heart-brain CTA.It can provide high image quality for assessing coronary and carotid cerebrovascular arteries.