Department of Radiology and Radiological Science, Division of Cardiovascular Imaging, Medical University of South Carolina, Charleston, SC.
Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Frankfurt, Germany.
AJR Am J Roentgenol. 2020 Nov;215(5):1049-1056. doi: 10.2214/AJR.20.22777. Epub 2020 Sep 22.
The purpose of this study was to prospectively evaluate, using software support, the feasibility and the quantitative and qualitative image quality parameters of a tube voltage-tailored contrast medium (CM) application protocol for patient-specific injection during coronary CT angiography (CCTA). In the Voltage-Based Contrast Media Adaptation in Coronary Computed Tomography Angiography (VOLCANIC-CTA) study, a single-center trial, 120 patients referred for CCTA were prospectively assigned to a tube voltage-tailored CM injection protocol. Automated tube voltage levels were selected in 10-kV intervals and ranged from 70 to 130 kV, and the iodine delivery rate (IDR) was adapted to the tube voltage level using dedicated software. The administered CM volume (370 mg I/mL) ranged from 33 mL at 70 kV (IDR, 0.7 g I/s) to 65 mL at 130 kV (IDR, 1.7 g I/s). Attenuation was measured in the aorta and coronary arteries to calculate quantitative signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), and 5-point scales were used to evaluate overall image quality. Radiation metrics were also assessed and compared among the protocols. The mean age of the study patients was 62.5 ± 11.9 (SD) years. Image quality was rated as diagnostic in all patients. Contrast attenuation peaked at 70 kV ( < 0.001), whereas SNR and CNR parameters showed no significant differences between tube voltage levels ( ≥ 0.085). Additionally, no significant differences in subjective image quality parameters were found among the different protocols ( ≥ 0.139). The lowest radiation dose values were observed in the group assigned to the 70-kV protocol, which had a median radiation effective dose of 2.0 mSv ( < 0.001). The proposed tube voltage-tailored injection protocol allows individualized scanning of patients undergoing CCTA and significantly reduces CM and radiation dose while maintaining a high diagnostic image quality.
这项研究的目的是前瞻性地评估，使用软件支持，为冠状动脉 CT 血管造影（CCTA）期间的患者特异性注射定制对比剂（CM）应用方案的可行性以及定量和定性的图像质量参数。在基于电压的冠状动脉 CT 血管造影中的对比剂适应性（VOLCANIC-CTA）研究中，这是一项单中心试验，前瞻性地将 120 名转诊进行 CCTA 的患者分配到一个管电压定制 CM 注射方案。自动管电压水平以 10kV 的间隔选择，范围从 70 到 130kV，碘输送率（IDR）使用专用软件适配管电压水平。使用的 CM 体积（370mgI/mL）范围从 70kV 时的 33ml（IDR，0.7gI/s）到 130kV 时的 65ml（IDR，1.7gI/s）。在主动脉和冠状动脉中测量衰减以计算定量信噪比（SNR）和对比噪声比（CNR），并使用 5 分制评估整体图像质量。还评估了辐射指标并比较了方案之间的差异。研究患者的平均年龄为 62.5 ± 11.9（SD）岁。所有患者的图像质量均被评为诊断性。对比衰减在 70kV 时达到峰值（<0.001），而 SNR 和 CNR 参数在管电压水平之间没有显著差异（≥0.085）。此外，在不同方案之间，主观图像质量参数也没有发现显著差异（≥0.139）。在分配给 70kV 方案的组中观察到最低的辐射剂量值，其辐射有效剂量中位数为 2.0mSv（<0.001）。所提出的管电压定制注射方案允许对进行 CCTA 的患者进行个体化扫描，同时显著降低 CM 和辐射剂量，同时保持高诊断图像质量。
