Horiguchi Jun, Matsuura Noriaki, Yamamoto Hideya, Kiguchi Masao, Fujioka Chikako, Kitagawa Toshiro, Kohno Nobuoki, Ito Katsuhide
Department of Clinical Radiology, Hiroshima University Hospital, Hiroshima, Japan.
Acad Radiol. 2009 Feb;16(2):187-93. doi: 10.1016/j.acra.2008.05.017.
The purpose of this prospective study was to assess image noise and variability in repeated coronary artery calcium (CAC) scoring on low-dose prospective electrocardiographically-triggered 64-slice multidetector computed tomography.
Patients (n = 115) suspected of having coronary artery disease were scanned twice, using a tube current of 10 x body mass index mA. The standard deviation (SD) of the computed tomographic value in the ascending aorta and (mean + 2 x SD) were obtained. Repeated CAC scores (Agatston, volume, and mass) were measured by two observers, and the interscan and interobserver variability were determined.
The mean tube current used was 246 +/- 36 mA. The mean tube current-time product and mean estimated effective dose were 57 +/- 8 mA and 0.9 +/- 0.2 mSv, respectively. The SD and (mean + 2 x SD) computed tomographic values in the ascending aorta were 16 +/- 3 and 75 +/- 10 Hounsfield units, respectively. Repeated CAC scores were correlated (r(2) = 0.995-0.998). The interscan variability for observer 1 and observer 2, respectively, were 13% and 13% for Agatston score, 12% and 11% for volume, and 11% and 11% for mass. The interobserver variability for scan 1 and scan 2, respectively, were 3% and 3% for Agatston score, 5% and 3% for volume, and 3% and 3% for mass.
Low-dose prospective electrocardiographically-triggered 64-slice multidetector computed tomography shows low interscan and interobserver variability on CAC scoring while maintaining low image noise.
本前瞻性研究的目的是评估在低剂量前瞻性心电图触发的64层多排螺旋计算机断层扫描中，重复进行冠状动脉钙化（CAC）评分时的图像噪声和变异性。
对115例疑似患有冠状动脉疾病的患者进行两次扫描，管电流为10×体重指数毫安。获取升主动脉内计算机断层扫描值的标准差（SD）以及（平均值 + 2×SD）。由两名观察者测量重复的CAC评分（阿加斯顿评分、体积和质量），并确定扫描间和观察者间的变异性。
使用的平均管电流为246±36毫安。平均管电流 - 时间乘积和平均估计有效剂量分别为57±8毫安和0.9±0.2毫希沃特。升主动脉内的SD和（平均值 + 2×SD）计算机断层扫描值分别为16±3和75±10亨氏单位。重复的CAC评分具有相关性（r² = 0.995 - 0.998）。观察者1和观察者2的扫描间变异性，阿加斯顿评分分别为13%和13%，体积分别为12%和11%，质量分别为11%和11%。扫描1和扫描2的观察者间变异性，阿加斯顿评分分别为3%和3%，体积分别为5%和3%，质量分别为3%和3%。
低剂量前瞻性心电图触发的64层多排螺旋计算机断层扫描在CAC评分中显示出较低的扫描间和观察者间变异性，同时保持低图像噪声。
