Department of Diagnostic Radiology, "San Gerardo" Hospital, Via Pergolesi 33, 20900, Monza, MB, Italy.
School of Medicine, University of Milano-Bicocca, Via Cadore 48, 20900, Monza, MB, Italy.
Radiol Med. 2017 Dec;122(12):893-901. doi: 10.1007/s11547-017-0800-4. Epub 2017 Aug 28.
Effective radiation dose in coronary CT angiography (CTCA) for coronary artery bypass graft (CABG) evaluation is remarkably high because of long scan lengths. Prospective electrocardiographic gating with iterative reconstruction can reduce effective radiation dose.
To evaluate the diagnostic performance of low-kV CT angiography protocol with prospective ecg-gating technique and iterative reconstruction (IR) algorithm in follow-up of CABG patients compared with standard retrospective protocol.
Seventy-four non-obese patients with known coronary disease treated with artery bypass grafting were prospectively enrolled. All the patients underwent 256 MDCT (Brilliance iCT, Philips) CTCA using low-dose protocol (100 kV; 800 mAs; rotation time: 0.275 s) combined with prospective ECG-triggering acquisition and fourth-generation IR technique (iDose; Philips); all the lengths of the bypass graft were included in the evaluation. A control group of 42 similar patients was evaluated with a standard retrospective ECG-gated CTCA (100 kV; 800 mAs).On both CT examinations, ROIs were placed to calculate standard deviation of pixel values and intra-vessel density. Diagnostic quality was also evaluated using a 4-point quality scale.
Despite the statistically significant reduction of radiation dose evaluated with DLP (study group mean DLP: 274 mGy cm; control group mean DLP: 1224 mGy cm; P value < 0.001). No statistical differences were found between PGA group and RGH group regarding intra-vessel density absolute values and SNR. Qualitative analysis, evaluated by two radiologists in "double blind", did not reveal any significant difference in diagnostic quality of the two groups.
The development of high-speed MDCT scans combined with modern IR allows an accurate evaluation of CABG with prospective ECG-gating protocols in a single breath hold, obtaining a significant reduction in radiation dose.
由于扫描长度较长，冠状动脉旁路移植术（CABG）评估的冠状动脉 CT 血管造影（CTCA）的有效辐射剂量非常高。前瞻性心电图门控与迭代重建相结合可以降低有效辐射剂量。
与标准回顾性方案相比，评估前瞻性 ECG 门控技术和迭代重建（IR）算法在 CABG 患者随访中的低千伏 CT 血管造影方案在诊断性能。
前瞻性纳入 74 名已知患有冠心病且接受动脉旁路移植术治疗的非肥胖患者。所有患者均接受 256 MDCT（Brilliance iCT，飞利浦）CTCA 检查，采用低剂量方案（100kV；800mAs；旋转时间：0.275s），结合前瞻性 ECG 触发采集和第四代 IR 技术（iDose；飞利浦）；所有旁路移植术的长度均包括在评估范围内。对 42 名类似的患者进行了对照组标准回顾性 ECG 门控 CTCA（100kV；800mAs）检查。在两次 CT 检查中，放置 ROI 以计算像素值和血管内密度的标准偏差。还使用 4 分质量量表评估诊断质量。
尽管通过 DLP 评估辐射剂量明显降低（研究组平均 DLP：274mGy cm；对照组平均 DLP：1224mGy cm；P 值<0.001）。在血管内密度绝对值和 SNR 方面，PGA 组和 RGH 组之间没有统计学差异。两名放射科医生在“双盲”条件下进行的定性分析未显示两组诊断质量存在任何显著差异。
高速 MDCT 扫描与现代 IR 相结合，允许在单次屏气中使用前瞻性 ECG 门控方案对 CABG 进行准确评估，同时显著降低辐射剂量。
