Diagnostic and Interventional Radiology Department, AP-HP Paris Saclay University, Bicêtre Hospital, Le Kremlin-Bicêtre, Le Kremlin Bicêtre, France.
Faculty of Medicine, Paris-Saclay University, Le Kremlin-Bicêtre, France.
Acta Radiol. 2024 Jan;65(1):3-13. doi: 10.1177/02841851231153797. Epub 2023 Feb 6.
Low-dose thoracic protocols were developed massively during the COVID-19 outbreak.
To study the impact on image quality (IQ) and the diagnosis reliability of COVID-19 low-dose chest computed tomography (CT) protocols.
COVID-19 low-dose protocols were implemented on third- and second-generation CT scanners considering two body mass index (BMI) subgroups (<25 kg/m and >25 kg/m). Contrast-to-noise ratios (CNR) were compared with a Catphan phantom. Next, two radiologists retrospectively assessed IQ for 243 CT patients using a 5-point Linkert scale for general IQ and diagnostic criteria. Kappa score and Wilcoxon rank sum tests were used to compare IQ score and CTDI between radiologists, protocols, and scanner models.
In vitro analysis of Catphan inserts showed in majority significantly decreased CNR for the low dose versus standard acquisition protocols on both CT scanners. However, in vivo, there was no impact on the diagnosis: sensitivity and specificity were ≥0.8 for all protocols and CT scanners. The third-generation scanner involved a significantly lower dose compared to the second-generation scanner (CTDI of 1.8 vs. 2.6 mGy for BMI <25 kg/m and 3.3 vs. 4.6 mGy for BMI >25 kg/m). Still, the third-generation scanner showed a significantly higher IQ with the low-dose protocol compared to the second-generation scanner (30.9 vs. 28.1 for BMI <25 kg/m and 29.9 vs. 27.8 for BMI >25 kg/m). Finally, the two radiologists had good global inter-reader agreement (kappa ≥0.6) for general IQ.
Low-dose protocols provided sufficient IQ independently of BMI subgroups and CT models without any impact on diagnosis reliability.
在 COVID-19 爆发期间，大量开发了低剂量胸部方案。
研究 COVID-19 低剂量胸部 CT（CT）方案对图像质量（IQ）和诊断可靠性的影响。
考虑到两个身体质量指数（BMI）亚组（<25 kg/m 和>25 kg/m），在第三代和第二代 CT 扫描仪上实施 COVID-19 低剂量方案。使用 Catphan 体模比较对比噪声比（CNR）。接下来，两名放射科医生使用 5 分 Linkert 量表对 243 名 CT 患者的 IQ 进行回顾性评估，用于一般 IQ 和诊断标准。Kappa 评分和 Wilcoxon 秩和检验用于比较放射科医生、方案和扫描仪模型之间的 IQ 评分和 CTDI。
Catphan 插件的体外分析表明，在两种 CT 扫描仪上，与标准采集方案相比，大多数低剂量方案的 CNR 均显著降低。然而，在体内，所有方案和 CT 扫描仪的诊断均无影响：灵敏度和特异性均≥0.8。与第二代扫描仪相比，第三代扫描仪的剂量明显较低（BMI<25 kg/m 时 CTDI 为 1.8 与 2.6 mGy，BMI>25 kg/m 时 CTDI 为 3.3 与 4.6 mGy）。尽管如此，与第二代扫描仪相比，第三代扫描仪的低剂量方案仍显示出更高的 IQ（BMI<25 kg/m 时为 30.9 与 28.1，BMI>25 kg/m 时为 29.9 与 27.8）。最后，两名放射科医生对一般 IQ 的全局读者间一致性较好（kappa≥0.6）。
低剂量方案在不影响诊断可靠性的情况下，无论 BMI 亚组和 CT 模型如何，均能提供足够的 IQ。
