Kapoor Atul, Mahajan Goldaa, Kapoor Aprajita
Advanced Diagnostics and Institute of Imaging, Amritsar, Punjab, India.
Indian J Radiol Imaging. 2022 Jan 10;31(4):910-916. doi: 10.1055/s-0041-1741102. eCollection 2021 Oct.
The aim of this study was to evaluate the use of low peak kilovoltage (kVp) low-volume iodinated contrast protocol for performing coronary computed tomography (CT) angiography (CCTA) in patients using retrospective electrocardiogram (ECG) gating. Hundred prospective patients undergoing CCTA were studied in two groups, A and B, using 70 kilovoltage (kV) and 120 kV protocols with half and standard intravenous volumes of injected iodinated contrast, respectively. All patients had heart rates less than 100 beats/min and body mass index (BMI) less than 31 kg/m . Both the groups were evaluated for signal-to-noise (S/N) and contrast-to-noise (C/N) ratios along with radiation dose delivered in millisievert (mSv), and for image quality (IQ), on per patient and per segment basis. Patients with group A showed statistically reduced radiation dose of 1.86 mSv compared with 6.86 mSv in group B patients. Marked reduction in image noise with statistically improved S/N and C/N ratios in all coronary vessels was seen in group A. S/N ratios in group A were 20.25, 18.68, 19.04, 17.41, and 18.69 for aorta, left main, left anterior descending, right coronary, and left circumflex arteries while they were 13.34, 11.12, 10.96, 9.74, and 8.67 in group B patients. C/N ratios were also higher in all vessels in group A patients, that is, 19.48, 19.48, 19.04, 19.48, and 17.68, compared with group B patients, who had 12.43, 10.03, 9.23, 9.57, and 8.23 ratios ( < 0.0001). No significant difference in IQ per patient and per vessel was seen between both the groups. Retrospective ECG-gated low-kVp low-volume iodinated contrast protocol provides good diagnostic quality angiograms in patients with BMI up to 31 kg/m and with heart rates of less than 100 beats/min with three times reduced radiation dose. The reduced volume of contrast reduces the cost as well as the chance of contrast-induced nephropathy.
本研究的目的是评估使用低峰值千伏（kVp）低剂量碘对比剂方案，通过回顾性心电图（ECG）门控技术对患者进行冠状动脉计算机断层扫描（CT）血管造影（CCTA）的效果。 对100例接受CCTA的前瞻性患者进行分组研究，分为A组和B组，分别采用70千伏（kV）和120 kV方案，并分别使用半量和标准静脉注射量的碘对比剂。所有患者心率均低于100次/分钟，体重指数（BMI）均低于31 kg/m²。对两组患者均评估了信噪比（S/N）和对比噪声比（C/N），以及以毫西弗（mSv）为单位的辐射剂量，并评估了每位患者和每个节段的图像质量（IQ）。 A组患者的辐射剂量经统计分析较B组患者降低，分别为1.86 mSv和6.86 mSv。A组所有冠状动脉血管的图像噪声均显著降低，S/N和C/N比值在统计学上有所改善。A组患者主动脉、左主干、左前降支、右冠状动脉和左旋支动脉的S/N比值分别为20.25、18.68、19.04、17.41和18.69，而B组患者分别为13.34、11.12、10.96、9.74和8.67。A组患者所有血管的C/N比值也更高，分别为19.48、19.48、19.04、19.48和17.68，而B组患者分别为12.43、10.03、9.23、9.57和8.23（P＜0.0001）。两组患者在每位患者和每个血管的IQ方面均未观察到显著差异。 回顾性ECG门控低kVp低剂量碘对比剂方案可为BMI高达31 kg/m²且心率低于100次/分钟的患者提供诊断质量良好的血管造影图像，同时辐射剂量降低了三分之二。对比剂用量的减少降低了成本以及对比剂肾病的发生几率。
