Interobserver variability in quality assessment of magnetic resonance images

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RESEARCH ARTICLE

Open Access

Interobserver variability in quality assessment of magnetic resonance images Rafal Obuchowicz1 , Mariusz Oszust2 and Adam Piorkowski3* Abstract Background: The perceptual quality of magnetic resonance (MR) images influences diagnosis and may compromise the treatment. The purpose of this study was to evaluate how the image quality changes influence the interobserver variability of their assessment. Methods: For the variability evaluation, a dataset containing distorted MRI images was prepared and then assessed by 31 experienced medical professionals (radiologists). Differences between observers were analyzed using the Fleiss’ kappa. However, since the kappa evaluates the agreement among radiologists taking into account aggregated decisions, a typically employed criterion of the image quality assessment (IQA) performance was used to provide a more thorough analysis. The IQA performance of radiologists was evaluated by comparing the Spearman correlation coefficients, ρ, between individual scores with the mean opinion scores (MOS) composed of the subjective opinions of the remaining professionals. Results: The experiments show that there is a significant agreement among radiologists (κ = 0.12; 95% confidence interval [CI]: 0.118, 0.121; P < 0.001) on the quality of the assessed images. The resulted κ is strongly affected by the subjectivity of the assigned scores, separately presenting close scores. Therefore, the ρ was used to identify poor performance cases and to confirm the consistency of the majority of collected scores (ρmean = 0.5706). The results for interns (ρmean = 0.6868) supports the finding that the quality assessment of MR images can be successfully taught. Conclusions: The agreement observed among radiologists from different imaging centers confirms the subjectivity of the perception of MR images. It was shown that the image content and severity of distortions affect the IQA. Furthermore, the study highlights the importance of the psychosomatic condition of the observers and their attitude. Keywords: Radiologists, Quality perception, Fleiss’ kappa, Decision process

Background The perception of pathologies in the displayed medical resonance (MR) images is often subjective and thus may lead to false-negative errors [22, 24]. Therefore, many clinical studies have been carried out to evaluate the radiological expertise as a part of clinical decision making [25, 32]. Consequently, factors which influence the perception became a matter of scientific discussion, resulting *Correspondence: [email protected] Department of Biocybernetics and Biomedical Engineering, AGH University of Science and Technology, Mickiewicza 30, 30-059, Cracow, Poland Full list of author information is available at the end of the article 3

in the foundation of the Medical Imaging Perception Society (MIPS). The society encourages and promotes medical image perception research and education. Such research involves an investigation of physical, social, and behavioral aspects which affect decision-making perfo