Application of an advanced noise reduction algorithm for imaging of hands in rheumatic diseases: evaluation of image quality compared to standard-dose images

• Published in: Rheumatology international 2020-06, Vol.40 (6), p.893-899
• Main Authors: Ziegeler, Katharina, Siepmann, Stefan, Hermann, Sandra, Beck, Alexander, Lembcke, Alexander, Hamm, Bernd, Hermann, Kay Geert A.
• Format: Article
• Language: English
• Subjects: Algorithms; Imaging; Medicine; Medicine & Public Health; Noise; Rheumatic diseases; Rheumatology
• ISSN: 0172-8172; 1437-160X
• DOI: 10.1007/s00296-020-04560-1

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.