OBJECTIVES X-ray is the fundamental imaging technique in both diagnosis and follow-up of rheumatic diseases. As patients often require sequential X-rays over many years, dose reduction is of great importance. New advanced noise reduction algorithms allow for a dose reduction of up to 50%. The aim of this study was to evaluate whether quality of low-dose images is non-inferior to standard-dose images and, therefore, application of this technique is possible in the context of imaging of rheumatic diseases. METHODS A total of 298 patients with known or suspected rheumatic disease were enrolled prospectively into this study, separated into three consecutive groups: 80%, 64% and 50% tube charge reduction. All patients received imaging of one hand (laterality randomly assigned) with low-dose technique and imaging of the contralateral hand with standard-dose protocol. Images were evaluated by two independent readers who scored (on a scale of 1-5) the visualization of bony cortex, trabeculae and joint spaces of fingers and wrist separately. Additionally, soft tissue and overall contrast were evaluated on the same scale. RESULTS Overall image quality (expressed by mean sum score out of 40) of the 50% low-dose images was 31.52 (SD 1.94) vs. 31.66 (SD 1.82) for standard images (p = 0.068). Bony contours as well as trabeculae were equally well visualized in both image sets. Median scores for soft tissue visualization was slightly lower for low dose compared to standard images [4 (IQR 3.5-4) vs. 4 (IQR 3.88-4); p = 0.001]. CONCLUSIONS Overall image quality of low-dose images was not inferior to standard-dose images. Therefore, the application of low-dose technology based on advanced noise estimation algorithms in the context of imaging of rheumatic diseases is possible.

中文翻译：

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先进的降噪算法在风湿性疾病手部成像中的应用：与标准剂量图像相比的图像质量评估。

目标 X 射线是风湿性疾病诊断和随访的基本成像技术。由于患者多年来经常需要连续进行 X 射线检查，因此减少剂量非常重要。新的先进降噪算法可减少高达 50% 的剂量。本研究的目的是评估低剂量图像的质量是否不劣于标准剂量图像，因此，该技术在风湿性疾病成像中的应用是可能的。方法 总共 298 名已知或疑似风湿性疾病的患者前瞻性地纳入本研究，分为三个连续组：80%、64% 和 50% 管电荷减少。所有患者均接受低剂量技术的一只手成像（随机分配的一侧）和采用标准剂量方案的对侧手成像。图像由两名独立的读者进行评估，他们分别对骨皮质、小梁以及手指和手腕的关节空间的可视化进行评分（按 1-5 级评分）。此外，还以相同的尺度评估软组织和整体对比度。结果 50% 低剂量图像的整体图像质量（以 40 分的平均总分表示）为 31.52 (SD 1.94)，而标准图像为 31.66 (SD 1.82) (p = 0.068)。骨轮廓和小梁在两个图像集中同样清晰可见。与标准图像相比，低剂量的软组织可视化中位得分略低[4 (IQR 3.5-4) vs. 4 (IQR 3.88-4)；p = 0.001]。结论 低剂量图像的整体图像质量并不逊色于标准剂量图像。因此，基于先进噪声估计算法的低剂量技术在风湿性疾病成像中的应用是可能的。