Paper
22 February 2012 Visual grading regression with random effects
Örjan Smedby, Mats Fredrikson, Jakob De Geer, Michael Sandborg
Author Affiliations +
Abstract
To analyze visual grading experiments, ordinal logistic regression (here called visual grading regression, VGR) may be used in the statistical analysis. In addition to types of imaging or post-processing, the VGR model may include factors such as patient and observer identity, which should be treated as random effects. Standard software does not allow random factors in ordinal logistic regression, but using Generalized Linear Latent And Mixed Models (GLLAMM) this is possible. In a single-image study, 9 radiologists graded 24 cardiac Computed Tomography Angiography (CTA) images with reduced dose without and after post-processing with a 2D adaptive filter, using five image quality criteria. First, standard ordinal logistic regression was carried out, treating filtering, patient and observer identity as fixed effects. The same analysis was then repeated with GLLAMM, treating filtering as a fixed effect and patient and observer identity as random effects. With both approaches, a significant effect (p<0.01) of the filtering was found for all five criteria. No dramatic differences in parameter estimates or significance levels were found between the two approaches. It is concluded that random effects can be appropriately handled in VGR using GLLAMM, but no major differences in the results were found in a preliminary evaluation.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Örjan Smedby, Mats Fredrikson, Jakob De Geer, and Michael Sandborg "Visual grading regression with random effects", Proc. SPIE 8318, Medical Imaging 2012: Image Perception, Observer Performance, and Technology Assessment, 831805 (22 February 2012); https://doi.org/10.1117/12.913650
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Cited by 5 scholarly publications.
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KEYWORDS
Visualization

Image quality

Image quality standards

Statistical analysis

Visual analytics

Image filtering

Computed tomography

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