Department of Life Sciences and Health, Faculty of Health Science, Oslo Metropolitan University Oslo, Norway.
Department of Radiology and Nuclear Medicine, Oslo University Hospital, Norway.
Eur J Radiol. 2024 Sep;178:111642. doi: 10.1016/j.ejrad.2024.111642. Epub 2024 Jul 24.
To benchmark image quality and corresponding radiation doses for acute abdominal CT examination across different laboratories and CT manufacturers.
An anthropomorphic phantom was scanned once with local abdominal CT protocols at 40 CT scanners, from four vendors, in thirty-three sites. Quantitative image quality was evaluated by CNR and SNR in the liver and kidney parenchyma. Qualitative image quality was assessed by visual grading analysis performed by three experienced radiologists using a five-point Likert scale to score thirteen image quality criteria. The CTDI was recorded for each scan. Pearson's correlation coefficient was calculated for the continuous variables, and the intraclass correlation coefficient was used to investigate interrater reliability between the radiologists.
CTDI ranged from 3.5 to 12 mGy (median 5.3 mGy, third quartile 6.7 mGy). SNR in liver parenchyma ranged from 4.4 to 14.4 (median 8.5), and CNR ranged from 2.7 to 11.2 (median 6.1). A weak correlation was found between CTDI and CNR (r = 0.270, p = 0.092). Variations in CNR across scanners at the same dose level CTDI were observed. No significant difference in CTDI or CNR was found based on scanner installation year. The oldest scanners had a 15 % higher median CTDI and a 12 % lower median CNR. The ICC showed acceptable agreement for all dose groups: low (ICC=0.889), medium (ICC=0.767), high (ICC=0.847), and in low (ICC=0.803) and medium (ICC=0.811) CNR groups.
There was large variation in radiation dose and image quality across the different CT scanners. Interestingly, the weak correlation between CTDI and CNR indicates that higher doses do not consistently improve CNR, indicating a need for systematic assessment and optimization of image quality and radiation doses for the abdominal CT examination.
在不同的实验室和 CT 制造商之间对急性腹部 CT 检查的图像质量和相应的辐射剂量进行基准测试。
使用局部腹部 CT 协议，在四个供应商的 40 台 CT 扫描仪上对一个人体模型进行了单次扫描，共在三十三个站点进行。通过在肝脏和肾脏实质中测量 CNR 和 SNR 来评估定量图像质量。使用五点李克特量表对 13 项图像质量标准进行视觉分级分析，由三位经验丰富的放射科医生评估定性图像质量。为每次扫描记录 CTDI。对连续变量进行 Pearson 相关系数分析，并使用组内相关系数来研究放射科医生之间的评分者间可靠性。
CTDI 范围为 3.5 至 12 mGy（中位数为 5.3 mGy，第三四分位数为 6.7 mGy）。肝实质中的 SNR 范围为 4.4 至 14.4（中位数为 8.5），CNR 范围为 2.7 至 11.2（中位数为 6.1）。在 CTDI 和 CNR 之间发现了微弱的相关性（r=0.270，p=0.092）。在相同剂量水平 CTDI 下，观察到扫描仪之间 CNR 的变化。根据扫描仪的安装年份，CTDI 或 CNR 没有显著差异。最旧的扫描仪的中位数 CTDI 高 15%，中位数 CNR 低 12%。对于所有剂量组，ICC 都显示出可接受的一致性：低（ICC=0.889）、中（ICC=0.767）、高（ICC=0.847），以及低（ICC=0.803）和中（ICC=0.811）CNR 组。
不同的 CT 扫描仪之间的辐射剂量和图像质量存在很大差异。有趣的是，CTDI 和 CNR 之间的弱相关性表明，更高的剂量并不总是能提高 CNR，这表明需要对腹部 CT 检查的图像质量和辐射剂量进行系统评估和优化。
