Department of Radiology, University of British Columbia/ Vancouver General Hospital, 899 W 12th Ave, Vancouver, BC, V5Z 1M9, Canada.
Faculty of Medicine, University of British Columbia, 317 - 2194 Health Sciences Mall, Vancouver, V6T 1Z3, BC, Canada.
Eur Radiol. 2020 May;30(5):2712-2721. doi: 10.1007/s00330-019-06650-6. Epub 2020 Feb 5.
To compare the scan acquisition time, radiation dose, subjective and objective image quality of two dual-source CT scanners (DSCT) for detection of acute pulmonary embolism.
Two hundred twenty-one scans performed on the 2nd-generation DSCT and 354 scans on the 3rd-generation DSCT were included in this large retrospective study. In a randomized blinded design, two radiologists independently reviewed the scans using a 5-point Likert scale. Radiation dose and objective image quality parameters were calculated.
Mean acquisition time was significantly lower in the 3rd-generation DSCT (2.81 s ± 0.1 in comparison with 9.7 s ± 0.15 [mean ± SD] respectively; p < 0.0001) with the 3rd generation 3.4 times faster. The mean subjective image quality score was 4.33/5 and 4/5 for the 3rd- and 2nd-generation DSCT respectively (p < 0.0001) with strong interobserver reliability agreement. DLP, CTDI, and ED were significantly lower in the 3rd than the 2nd generation (175.6 ± 63.7 mGy cm; 5.3 ± 1.9 mGy and 2.8 ± 1.2 mSv in comparison with 266 ± 255 mGy.cm; 7.8 ± 2.2 mGy and 3.8 ± 4.3 mSv). Noise was significantly lower in the 3rd generation (p < 0.01). Signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM), a dose-insensitive index for CNR, were significantly higher in the 3rd-generation DSCT (33.5 ± 23.4; 29.0 ± 21.3 and 543.7 ± 1037 in comparison with 23.4 ± 17.7; 19.4 ± 16.0 and 170.5 ± 284.3).
Objective and subjective image quality are significantly higher on the 3rd-generation DSCT with significantly lower mean acquisition time and radiation dose.
• The 3rd-generation DSCT scanner provides an improved image quality, less perceived artifacts, and lower radiation dose in comparison with the 2nd-generation DSCT, when operating in dual-energy (DE) mode. • The 3.4-times-faster 3rd-generation DSCT scanner can be of particular value in patients with chronic lung diseases or breathing difficulties that prevent adequate breathhold.
比较两种双源 CT 扫描仪（DSCT）在检测急性肺栓塞方面的扫描采集时间、辐射剂量、主观和客观图像质量。
本大规模回顾性研究纳入了 221 例第二代 DSCT 扫描和 354 例第三代 DSCT 扫描。采用随机盲法设计，两名放射科医生使用 5 分制量表独立对扫描进行评估。计算辐射剂量和客观图像质量参数。
第三代 DSCT 的平均采集时间明显更短（分别为 2.81s±0.1 与 9.7s±0.15[平均值±标准差]；p<0.0001），采集速度快 3.4 倍。第三代和第二代 DSCT 的平均主观图像质量评分分别为 4.33/5 和 4/5（p<0.0001），观察者间一致性较强。与第二代相比，第三代的剂量长度乘积（DLP）、容积 CT 剂量指数（CTDI）和有效剂量（ED）显著降低（分别为 175.6±63.7mGy·cm；5.3±1.9mGy 和 2.8±1.2mSv 与 266±255mGy·cm；7.8±2.2mGy 和 3.8±4.3mSv）。第三代的噪声显著降低（p<0.01）。第三代的信噪比（SNR）、对比噪声比（CNR）和不敏感于剂量的 CNR 质量因数（FOM）均显著升高（分别为 33.5±23.4；29.0±21.3 和 543.7±1037 与 23.4±17.7；19.4±16.0 和 170.5±284.3）。
第三代 DSCT 的客观和主观图像质量均显著提高，平均采集时间和辐射剂量显著降低。
第三代 DSCT 扫描仪在双能（DE）模式下与第二代 DSCT 相比，提供了更高的图像质量、更少的感知伪影和更低的辐射剂量。
3.4 倍更快的第三代 DSCT 扫描仪对于患有慢性肺部疾病或呼吸困难而无法充分屏气的患者尤其有价值。
