Department of Radiology and Department of Medicine, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada.
J Cardiovasc Comput Tomogr. 2013 Jan-Feb;7(1):18-24. doi: 10.1016/j.jcct.2013.01.001. Epub 2013 Jan 19.
Prospectively triggered coronary computed tomography angiography (CTA) is commonly performed with a widened acquisition window to provide flexibility in image reconstruction.
We conducted a randomized controlled trial to determine whether the use of a narrow acquisition window in prospectively triggered coronary CTA would allow lower radiation dose while preserving image quality and interpretability.
Prospective 2-center 2- platform randomized trial that evaluated 205 consecutive patients 96 with widened acquisition (WA) and 109 narrow acquisition (NA) referred for coronary CTA in sinus rhythm and heart rate <65 beats/min. Patients scanned with WA had phases reconstructed at 5% intervals, and each phase was assigned an individual study ID. Images were reviewed with individual phase reconstructions interpreted randomly by 2 level 3 readers with a third for consensus. Images were evaluated with a 5-point Likert scale on a per-vessel basis (best score on any phase). Scores were then dichotomized into diagnostic (score 3-5) compared with nondiagnostic (score 1-2). Readers also reported obstructive coronary artery disease on a per-patient basis. Agreement for the diagnosis of obstructive disease and per-artery interpretability was performed. Signal and noise measurements were also performed.
No difference in demographics between groups (P = NS). The signal-to-noise ratio was comparable 12.99 ± 3.4 NA and 12.53 ± 4.13 for the WA (P = 0.45). The median effective dose was 1.78 mSv for NA compared with 3.26 mSv for WA (P < 0.001). Image quality, diagnostic interpretability, interreader agreement, and downstream testing were not significantly different between the 2 groups (P= NS for all).
Coronary CTA with NA resulted in a 47% lower radiation dose without significant difference in study interpretability or image quality or increased downstream resource use or testing.
前瞻性触发冠状动脉计算机断层扫描血管造影术（CTA）通常采用较宽的采集窗进行，以提供图像重建的灵活性。
我们进行了一项随机对照试验，以确定在前瞻性触发冠状动脉 CTA 中使用窄采集窗是否可以在保持图像质量和可解释性的同时降低辐射剂量。
前瞻性 2 中心 2 平台随机试验，评估了 205 例连续患者，96 例采用宽采集（WA），109 例采用窄采集（NA），用于窦性心律和心率<65 次/分钟的冠状动脉 CTA。采用 WA 扫描的患者以 5%的间隔重建相位，每个相位都有一个单独的研究 ID。图像由 2 名 3 级读者进行单独相位重建的随机解读，第 3 名读者进行共识解读。以 5 分制对每支血管进行评分（任何相位的最佳评分）。然后将评分分为诊断性（评分 3-5）和非诊断性（评分 1-2）。读者还按每位患者报告了阻塞性冠状动脉疾病。进行了阻塞性疾病和每支动脉可解释性的诊断一致性评估。还进行了信号和噪声测量。
两组患者的人口统计学特征无差异（P>0.05）。信噪比相似，NA 为 12.99±3.4，WA 为 12.53±4.13（P>0.05）。NA 的中位有效剂量为 1.78 mSv，WA 为 3.26 mSv（P<0.001）。两组间图像质量、诊断可解释性、读者间一致性和下游检测无显著差异（所有 P>0.05）。
NA 进行冠状动脉 CTA 可降低 47%的辐射剂量，而不会显著影响研究可解释性或图像质量，也不会增加下游资源使用或检测。
