双源CT前瞻性心电门控扫描在急性胸痛诊断中应用的可行性

目的探讨应用双源CT(dual-source CT,DSCT)前瞻性心电门控扫描对不同心率的急性胸痛患者诊断的可行性。方法对42例急性胸痛患者进行DSCT前瞻性心电门控心胸联合扫描,并将患者分为两组,A组患者心率≤75次/min,采集时相选择70%R-R间期,心电脉冲窗设为62%～78%,B组患者心率>75次/min,采集时相选择40%R-R间期,心电脉冲窗设为32%～48%。由两名有经验的放射科医师对两组患者的肺动脉、主动脉、冠状动脉进行靶重组,评价图像质量,并进行诊断,同时计算出辐射剂量;应用χ2检验和两独立样本t检验比较两组图像的诊断价值,其中16例冠状动脉结果与血管造影结果对比。结果仅1例主动脉CT值未达到诊断标准,两组肺动脉、主动脉平均CT值差异无统计学意义(t值分别为0.254、0.700,P值均>0.05);A、B两组可评价冠状动脉节段分别为278/284(97.89%)、297/307(96.74%),差异无统计学意义;其中16例冠状动脉结果与血管造影结果对比有较好的一致性;患者接受的平均有效剂量为(8.67±2.54)mSv。结论 DSCT前瞻性心电门控心胸联合扫描在无需控制心率情况下能获得较好的图像质量。

Feasibility of Prospective EGG-Dual-Source CT in the Diagnosis of Patients with Acute Chest Pain

Objective To evaluate the feasibility of prospective ECG gated dual-source CT(DSCT)in patients with acute chest pain in different heart rate.Methods Forty two patients with acute chest pain underwent prospective ECG-gated DSCT scan.The patients were divided into two groups.In group A,the heart rate of patients was ≤ 75 beats / min,data set was reconstructed in 70% R-R interval,ECG pulse window was set to 62%-78%.In group B,the heart rate of patients was > 75 beats / min,data set was reconstructed in 40% R-R interval,ECG pulse window was set to 32%-48%.Two experienced radiologists assessed the image quality of two groups,The images were target reconstructed on pulmonary artery,aorta,coronary arteries,and the radiation dose was calculated.χ2 test was used to explore significant differences in assessable segments coronary artery.Two independent samples t-test was used to explore significant differences in vessel attenuation of ascending aorta and pulmonary trunk.As well as,the CT coronary angiographic images of 16 cases were compared with DSA.Results Only one case,the attenuation of ascending aorta did not meet the diagnostic criteria.The attenuation of ascending aorta and pulmonary trunk had not statistical difference between group A and B(t values were 0.254,0.700,P values were>0.05).The assessable segments of coronary arteries of group A and B were 278/284(97.89%),297/307(96.74%),and there was no statistical difference between two groups.There was good consistency between CT coronary angiographic images and DSA images.The average effective dose was(8.67 ± 2.54)mSv.Conclusion Prospective ECG gated DSCT angiography offers a very good image quality without heart rate control in patients with acute chest pain.