Department of Cardiovascular Imaging, Centro Hospitalar Gaia/Espinho, Porto, Portugal.
Heart Lung Circ. 2011 Feb;20(2):119-25. doi: 10.1016/j.hlc.2010.09.005. Epub 2010 Oct 13.
new technologies for computed tomography coronary arteries imaging aim to reduce the radiation dose whilst maintaining image quality. The purpose of our study was to compare radiation dose and image quality parameters of Coronary Computed Tomography Angiography (CCTA) performed with retrospective 64-MDCT and prospective 128-MDCT.
a series of 77 consecutive patients were first randomised to either retrospective 64-MDCT (n=37) or prospective 128-MDCT (n=40) for CCTA. All patients in the retrospective 64-MDCT group were scanned with tube current modulation as strategy for reduction dose. Data regarding acquisition time and radiation dose were recorded. Two blinded radiologists independently assessed image quality of all coronary segments by using a four-point scale (1, excellent; 4, poor). Discrepancies were settled by consensus.
No significant differences were found regarding sex, age, body weight and heart rate. CTTA effective radiation dose was 2.1 ± 0.9 vs. 8.2 ± 4mSv in prospective and retrospective ECG-gating MDCT groups, respectively. Mean image quality score was 2.2 ± 0.9 for prospective 128-MDCT group and 1.4 ± 0.7 points for retrospective 64-MDCT representing a mean difference of 0.8 points (CI: 0.9 to 0.7).
in selected patients, CCTA using a 128-MDCT with prospective ECG-gating provides higher image quality with significant lower radiation dose when compared to 64-MDCT using retrospective ECG-gating.
用于冠状动脉 CT 成像的新技术旨在降低辐射剂量，同时保持图像质量。本研究的目的是比较使用回顾性 64 层 MDCT 和前瞻性 128 层 MDCT 进行冠状动脉 CT 血管造影（CCTA）的辐射剂量和图像质量参数。
首先将 77 例连续患者随机分为回顾性 64 层 MDCT（n=37）或前瞻性 128 层 MDCT（n=40）进行 CCTA。回顾性 64 层 MDCT 组中的所有患者均采用管电流调制策略进行剂量降低扫描。记录采集时间和辐射剂量的数据。两名盲法放射科医生独立使用 4 分制（1 分，优秀；4 分，差）评估所有冠状动脉节段的图像质量。意见分歧通过共识解决。
性别、年龄、体重和心率方面无显著差异。前瞻性 ECG 门控 MDCT 和回顾性 ECG 门控 MDCT 组的 CTTA 有效辐射剂量分别为 2.1±0.9 和 8.2±4mSv。前瞻性 128 层 MDCT 组的平均图像质量评分为 2.2±0.9，回顾性 64 层 MDCT 组为 1.4±0.7 分，平均差异为 0.8 分（置信区间：0.9 至 0.7）。
在选定的患者中，与使用回顾性 ECG 门控的 64 层 MDCT 相比，前瞻性 ECG 门控的 128 层 MDCT 进行 CCTA 可提供更高的图像质量，同时辐射剂量显著降低。
