Adam Nevo, Nahum Goldberg S, Marron Daud, Romman Zimam, Wissam Zeineh, Jacob Sosna, Naama Lev-Cohain
Hadassah Medical Center, Radiology Department, Israel.
Eur J Radiol. 2025 Oct;191:112282. doi: 10.1016/j.ejrad.2025.112282. Epub 2025 Jul 17.
Contrast-enhanced dual energy CT, with low-mono-energetic CT scanning (conventional 70 keV and low-mono energetic 40 keV) can improve visualization of acute inflammatory processes, but the high iodine attenuation often requires adjustment of window display settings to optimize interpretation. Here, we aim to determine optimal keV and window settings for the visualization of acute appendicitis from images derived from low-mono-energetic-CT.
34 patients diagnosed with appendicitis, using dual energy CT, were retrospectively identified. An iterative four-dimensional Simplex optimization algorithm was used to determine optimal keV and windowing for assessment. 14 different keVs (40-70 range) and window parameters (center 5-290 HU; width 205-570 HU) were evaluated by 6 radiologists. Each reader individually graded the conspicuity of appendix wall enhancement using a 5-point scale and the overall image quality on a 3-point scale. Three-dimensional contour maps of the relationship between window settings and overall averages of reader grade at 40 keV were constructed.
Convergence to optimal windowing was achieved over ten parameter iterations following the initial evaluation of 4 different parameter sets. This amounted to a total of 2,856 reads (14 keVs and window settings x 6 readers x 34 cases). The highest average conspicuity grade (4.4 ± 0.0) was achieved at 40 keV with windows of 57-79 HU center and 357-418 HU width, with best background in this range at window 57 HU and center 418 HU.
Algorithmic optimization of dual energy contrast-enhanced CT scans may allow better visualization of acute inflammatory pathological processes such as mucosal enhancement in appendicitis by tailoring keV levels and window settings.
对比增强双能量CT结合低单能CT扫描（传统的70keV和低单能40keV）可改善急性炎症过程的可视化，但高碘衰减通常需要调整窗口显示设置以优化解读。在此，我们旨在从低单能CT图像中确定用于可视化急性阑尾炎的最佳keV和窗口设置。
回顾性纳入34例经双能量CT诊断为阑尾炎的患者。采用迭代四维单纯形优化算法确定评估的最佳keV和窗宽。6名放射科医生评估了14种不同的keV（40 - 70范围）和窗口参数（中心值5 - 290HU；宽度205 - 570HU）。每位读者分别使用5分制对阑尾壁强化的清晰度进行评分，并使用3分制对整体图像质量进行评分。构建了40keV时窗口设置与读者评分总体平均值之间关系的三维等高线图。
在对4组不同参数集进行初始评估后的十次参数迭代中实现了向最佳窗宽的收敛。这总计进行了2856次读片（14种keV和窗口设置×6名读者×34例病例）。在40keV、中心值57 - 79HU且宽度357 - 418HU的窗口设置下，平均清晰度评分最高（4.4±0.0），在此范围内窗口中心值418HU、背景最佳的是窗口57HU。
双能量对比增强CT扫描的算法优化可能通过调整keV水平和窗口设置，更好地可视化急性炎症病理过程，如阑尾炎中的黏膜强化。
