Spears J Reid, Schoepf U Joseph, Henzler Thomas, Joshi Gayatri, Moscariello Antonio, Vliegenthart Rozemarijn, Cho Young Jun, Apfaltrer Paul, Rowe Garrett, Weininger Markus, Ebersberger Ullrich
Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260.
Heart and Vascular Center, Medical University of South Carolina, Ashley River Tower, 25 Courtenay Drive, Charleston, SC, 29425-2260.
Acad Radiol. 2014 Mar;21(3):318-24. doi: 10.1016/j.acra.2013.11.008. Epub 2013 Dec 18.
To investigate the impact of iterative reconstruction in image space (IRIS) on image noise, image quality (IQ), and postprocessing at coronary computed tomography angiography (cCTA) compared to traditional filtered back-projection (FBP).
The cCTA results of 50 patients (26 men; 58 ± 15 years, body mass index 31.5 ± 6.7 kg/m²) were investigated using a second-generation dual-source computed tomography system. Scan data were reconstructed with the use of IRIS and FBP algorithms. Two radiologists independently evaluated the reconstructions using automated coronary tree analysis software. Image noise was measured and IQ was rated on a 5-point Likert scale. The number of manual corrections after automated vessel segmentation, the time required to complete segmentation, and the number of missed segments were assessed in both IRIS and FBP reconstructions. Results were compared using paired t-test.
IRIS significantly reduced image noise compared to FBP (23.3 ± 8.8 vs. 33.5 ± 13.5 Hounsfield units, P < .001). Subjective IQ improved with IRIS (IRIS 3.2 ± 1.0 vs. FBP 3.0 ± 1.0, P < .05). IRIS decreased the time needed for coronary segmentation from 111.9 ± 40.5 seconds to 95.2 ± 38.2 seconds with FBP (P < .01) and required fewer manual corrections (5.7 ± 3.0 vs. 6.8 ± 3.6, P < .01). The number of missed vessel segments was not significantly different (3.6 ± 1.8 vs. 3.8 ± 1.9, P > .05) between IRIS and FBP, respectively.
During cCTA postprocessing, IRIS significantly decreases the time and the number of manual corrections for a complete coronary segmentation compared to FBP. This effect is likely attributable to suppression of image noise by IRIS, which improves the performance of automated vessel segmentation and positively impacts cCTA analysis.
与传统的滤波反投影（FBP）相比，研究图像空间迭代重建（IRIS）对冠状动脉计算机断层扫描血管造影（cCTA）图像噪声、图像质量（IQ）及后处理的影响。
使用第二代双源计算机断层扫描系统对50例患者（26名男性；年龄58±15岁，体重指数31.5±6.7kg/m²）的cCTA结果进行研究。扫描数据采用IRIS和FBP算法重建。两名放射科医生使用自动冠状动脉树分析软件独立评估重建图像。测量图像噪声，并采用5分制李克特量表对IQ进行评分。在IRIS和FBP重建中，评估自动血管分割后手动校正的次数、完成分割所需的时间以及遗漏节段的数量。采用配对t检验比较结果。
与FBP相比，IRIS显著降低了图像噪声（23.3±8.8与33.5±13.5亨氏单位，P<.001）。IRIS使主观IQ得到改善（IRIS为3.2±1.0，FBP为3.0±1.0，P<.05）。IRIS将冠状动脉分割所需时间从FBP的111.9±40.5秒减少至95.2±38.2秒（P<.01），且所需手动校正更少（5.7±3.0与6.8±3.6，P<.01）。IRIS和FBP之间遗漏血管节段的数量无显著差异（分别为3.6±1.8与3.8±1.9，P>.05）。
在cCTA后处理过程中，与FBP相比，IRIS显著减少了完整冠状动脉分割的时间和手动校正次数。这种效果可能归因于IRIS对图像噪声的抑制，这提高了自动血管分割的性能，并对cCTA分析产生积极影响。
