Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT
Effect of Heart Rate and Body Mass Index on the Interscan and Interobserver Variability of Coronary Artery Calcium Scoring at Prospective ECG-Triggered 64-Slice CT
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DOI：
10.3348/kjr.2009.10.4.340
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发表时间：
2009-07-01
影响因子：
4.8
通讯作者：
Ito, Katsuhide
中科院分区：
文献类型：
--
作者：
Horiguchi, Jun;Matsuura, Noriaki;Ito, Katsuhide
目的：为了测试心率，体重指数（BMI）和噪声水平对扫描间和观察者间变异性的冠状动脉钙（CAC）评分的前瞻性心电图（ECG）触发64层CT.Materials和方法的影响：一百一十例（76例CAC）进行了两次扫描的前瞻性心电图触发扫描。扫描参数包括120 W、82 mAs、2.5 mm厚度和45% RR间期的采集中心。计算CAC评分（Agatston、体积和质量）的扫描间和观察者间变异性。影响变异性的因素通过将其与心率、BMI和噪声水平（定义为标准差：SD）作图来确定。平均心率为63 +/- 12 bpm（范围：44-101 bpm）。患者BMI为24.5 ± 4.5 kg/m2（范围：15.5-42.3 kg/m2）。扫描间变异的平均值和中位数分别为11%和6%，按体积，和11%和6%，分别按质量。此外，算法的平均值和中位数低于Agatston算法（分别为16%和9%）。观察者间变异性的平均值和中位数分别为10%和4%（算法的平均值）。平均噪音水平为15 +/- 4 Hounsfield单位（HU）（范围，8-25 HIJ）。扫描间和观察者间变异性与心率，体重指数，或noise level.Conclusion：扫描间和观察者间变异性CAC前瞻性心电触发64层CT高图像质量和45%的RR采集是不显着影响心率，体重指数，或噪声水平。与Agatston评分法相比，容积或质量算法显示扫描间变异性降低（p <0.05）。
Objective: To test the effects of heart rate, body mass index (BMI) and noise level on interscan and interobserver variability of coronary artery calcium (CAC) scoring on a prospective electrocardiogram (ECG)-triggered 64-slice CT.Materials and Methods: One hundred and ten patients (76 patients with CAC) were scanned twice on prospective ECG-triggered scans. The scan parameters included 120 W, 82 mAs, a 2.5 mm thickness, and an acquisition center at 45% of the RR interval. The interscan and interobserver variability on the CAC scores (Agatston, volume, and mass) was calculated. The factors affecting the variability were determined by plotting it against heart rate, BMI, and noise level (defined as the standard deviation: SD).Results: The estimated effective dose was 1.5 +/- 0.2 mSv. The mean heart rate was 63 +/- 12 bpm (range, 44-101 bpm). The patient BMIs were 24.5 +/- 4.5 kg/m(2) (range, 15.5-42.3 kg/m(2)). The mean and median interscan variabilities were 11% and 6%, respectively by volume, and 11% and 6%, respectively, by mass. Moreover, the mean and median of the algorithms were lower than the Agatston algorithm (16% and 9%, respectively). The mean and median interobserver variability was 10% and 4%, respectively (average of algorithms). The mean noise levels were 15 +/- 4 Hounsfield unit (HU) (range, 8-25 HIJ). The interscan and interobserver variability was not correlated with heart rate, BMI, or noise level.Conclusion: The interscan and interobserver variability of CAC on a prospective ECG-triggered 64-slice CT with high image quality and 45% of RR acquisition is not significantly affected by heart rate, BMI, or noise level. The volume or mass algorithms show reduced interscan variability compared to the Agatston scoring (p < 0 05).