摘要
目的探讨单扇区重建算法改善高心率患者非预期自由呼吸640层CT冠状动脉成像图像质量的可行性。方法2011年3月1日-8月31日期间,行640层CT冠状动脉成像时发生非预期自由呼吸的31例心率大于65次/min的患者被纳入本研究。31例患者的CT原始数据均采用单扇区重建算法、多扇区重建算法进行CT容积数据重建。由两名心血管放射医师以优(1分)、良(2分)、差(3分)3个等级独立评价每个病例的15个冠状动脉节段和左、右肺血管的图像质量。比较两种重建算法的信噪比、对比噪声比。结果采用单扇区重建算法,图像质量可诊断(优+良)的冠脉节段占97.9%,相比较于多扇区重建算法69.5%的可诊断率,两组有明显的统计学差异(P〈0.001)。两组间肺血管的图像质量也有明显的统计学差异(P〈0.001)。单扇区重建组的信噪比显著低于多扇区重建组(14.0±3.4比17.6±4.2,P〈0.001)。两种重建方法的对比噪声比在左冠状动脉主干、右冠状动脉初段、中段和末段均无统计学差异(P〉0.05)。结论单扇区重建技术可以改善非预期自由呼吸病例的640层CT冠状动脉成像的图像质量。
Objective To assess the image quality of half-cycle reconstruction of free-breathing 320-detector row coronary CT angiography (CTA) in patients with heart rates above 65 beats per minute. Methods From March 1 to August 31, 2011, 31 patients with unanticipated free-breathing during coronary CTA were included in the study. CTA was performed using the standard breath-holding method. All images were reconstructed using half-cycle reconstruction (HCR) and multi-cycle reconstruction (MCR) methods. The image quality for 15 segments of all coronary arteries was scored as 1 (excellent), 2 (good), and 3 (poor). The signal- to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared. Results With HCR, 97.4% of the coronary artery segments were evaluable with image quality scores of 1 and 2 compared to 65.6% with MCR group (P 〈 0.001). The image quality score of lung vessels was also significantly higher with HCR than that with MCR (P 〈 0.001). The SNR was significantly (P 〈 0.001) lower with HCR (14.0 + 3.4) than that with MCR (17.6 + 4.2). The CNRs were not significantly different in the left main coronary artery (P = 0.052), proximal right coronary artery ( P = 0.058), middle right coronary artery (P = 0.081) and distal right coronary artery ( P = 0.112) between the two reconstructive methods. Conclusions Half-cycle reconstruction can improve image quality of unanticipated free-breathing on 320-detector row coronary CTA in patients with heart rates above 65 beats per minute.
出处
《影像诊断与介入放射学》
2014年第1期22-26,共5页
Diagnostic Imaging & Interventional Radiology
关键词
冠状动脉CT造影
呼吸伪影
单扇区重建
多扇区重建
Coronary CT angiography
Respiration artifacts
Half-cycle reconstruction
Muhi-cycle reconstruction