Keller Gabriel, Hagen Florian, Neubauer Leoni, Rachunek Katarzyna, Springer Fabian, Kraus Mareen Sarah
Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.
Department of Radiation Protection, University Hospital Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany.
Quant Imaging Med Surg. 2022 Sep;12(9):4622-4632. doi: 10.21037/qims-21-1196.
Modern CT might deliver higher image quality than necessary for fracture imaging, which would mean non-essential effective radiation exposure for patients. We simulated ultra-low dose (ULD)-CT at different dose levels and analyzed their diagnostic performance for scaphoid fracture detection.
30 consecutive high quality CT with clinically suspected scaphoid fractures were assessed. ULD-simulations were made at 20%, 10% and 5% of original dose. Three readers at different levels of experience (expert, moderate, inexperienced) expressed their diagnostic confidence (DC; 5-point-Likert-scale) and analyzed the presence and classification of scaphoid fractures within Krimmer's and Herbert's classifications. Effective radiation exposure of the original data sets and ULD-CT were calculated.
At 20% and 10% dose the more experienced readers reached perfect sensitivity (100%) and specificity (100%), showing perfect agreement regarding fracture classification (1.00). Diagnostic performance decreased at 5% dose (92.86% sensitivity, 100% specificity; expert reader). The inexperienced reader showed reduced sensitivity and specificity at all dose levels. At 10% dose minimal DC of all readers was 3/5 and mean calculated effective radiation exposure was 1.11 [±0.36] µSv.
The results suggest that ULD-CT at 10% dose compared to high quality CT might offer sufficient image quality to precisely detect and classify scaphoid fractures, if moderate experience of the radiologist is granted.
现代CT可能提供高于骨折成像所需的图像质量，这意味着患者会受到不必要的有效辐射暴露。我们模拟了不同剂量水平的超低剂量（ULD）CT，并分析了它们在检测舟骨骨折方面的诊断性能。
对30例连续的临床疑似舟骨骨折的高质量CT进行评估。在原始剂量的20%、10%和5%下进行ULD模拟。三位经验水平不同的读者（专家、中级、无经验）表达了他们的诊断信心（DC；5级李克特量表），并分析了舟骨骨折在克里默分类法和赫伯特分类法中的存在情况和分类。计算原始数据集和ULD-CT的有效辐射暴露量。
在20%和10%剂量时，经验更丰富的读者达到了完美的敏感性（100%）和特异性（100%），在骨折分类方面显示出完美的一致性（1.00）。在5%剂量时诊断性能下降（敏感性92.86%，特异性100%；专家读者）。无经验的读者在所有剂量水平下敏感性和特异性均降低。在10%剂量时，所有读者的最小DC为3/5，平均计算有效辐射暴露量为1.11[±0.36]µSv。
结果表明，与高质量CT相比，10%剂量的ULD-CT可能提供足够的图像质量来精确检测和分类舟骨骨折，前提是放射科医生有一定的经验。
