CAJ | 학술논문

目的：探讨冠状动脉CT能谱成像(GSI)最佳单能量成像，以获得最好信噪比，得到最佳质量图像，为今后检查做出指导。方法应用宝石能谱CT(Discovery CT750 HD)，选取17例心率≤65次/min，波动≤3次/min，临床疑似冠心病患者进行冠状动脉CT能谱扫描(GSI)，重建其140kVp混合能量图像及6组单能量图像(90、80、70、60、50和40Kev)，测量、计算混合能量图像与各组单能量图像的背景噪声(SD)、图像信噪比(SNR)及对比噪声比(CNR)，筛选出最佳单能量图像与混合能量图像的图像质量进行主客观评价。结果70Kev单能量图像的SNR(39.39±5.56)及CNR(30.47±4.77)均高于其他单能量图像与混合能量图像，与混合能量图像相比，差异有统计学意义(P＜0.05)；90Kev、80Kev及70Kev单能量图像的背景噪声较140kvp混合能量图像分别减少32%、37%及30%；两组图像的主观评分：70Kev单能量图像的质量评分为4.72±0.56，评5分血管段为177段，占85%(177/208)，混合能量图像评分为4.57±0.58，评5分血管段为146，占71%(146/206)t值为25.01, P＜0.01。结论70Kev单能量图像是冠状动脉CT能谱成像的最佳单能量图像，图像质量明显优于140kvp混合能量图像。
목적：탐토관상동맥CT능보성상(GSI)최가단능량성상，이획득최호신조비，득도최가질량도상，위금후검사주출지도。방법응용보석능보CT(Discovery CT750 HD)，선취17례심솔≤65차/min，파동≤3차/min，림상의사관심병환자진행관상동맥CT능보소묘(GSI)，중건기140kVp혼합능량도상급6조단능량도상(90、80、70、60、50화40Kev)，측량、계산혼합능량도상여각조단능량도상적배경조성(SD)、도상신조비(SNR)급대비조성비(CNR)，사선출최가단능량도상여혼합능량도상적도상질량진행주객관평개。결과70Kev단능량도상적SNR(39.39±5.56)급CNR(30.47±4.77)균고우기타단능량도상여혼합능량도상，여혼합능량도상상비，차이유통계학의의(P＜0.05)；90Kev、80Kev급70Kev단능량도상적배경조성교140kvp혼합능량도상분별감소32%、37%급30%；량조도상적주관평분：70Kev단능량도상적질량평분위4.72±0.56，평5분혈관단위177단，점85%(177/208)，혼합능량도상평분위4.57±0.58，평5분혈관단위146，점71%(146/206)t치위25.01, P＜0.01。결론70Kev단능량도상시관상동맥CT능보성상적최가단능량도상，도상질량명현우우140kvp혼합능량도상。
Objective To investigate the optimal energy level for monochromatic reconstruction of coronary CT angiography with the use of cardiac spectral imaging.Methods 17 patients (HR<65/min,variation<3/min) underwent cardiac spectral imaging using GSI mode on a 64-slice CT scanner(Discovery CT 750 HD,GE healthcare). In 6 sets of monochromatic images(40,50,60,70,80 and 90kev), region of interest was put in the aortic root,signal-to-noise,contrast-to-noise and image quality(graded on a 5-point scale) were assessed in all monochromatic images and compared with the conventional polychromatic images.Results Compared with conventional polychromatic images and other monochromatic images, reconstruction with 70kev showed the highest SNR(39.39±5.56) and CNR (30.47±4.77). there was statistical difference on images noise (11.57±1.34vs16.63±1.97),subjective image score(4.72±0.56vs4.57±0.58),and percentage of segment of 5 point(85% vs 71%) between 70kev and polychromatic images(P<0.05).Conclustions Cardiac Spectral Imaging with reconstruction of 70kev offers best image quality of coronary CTangiography compared with other monochromatic images and polychromatic images.