A Psychological Perspective on Image Interpretation in Acute Ischemic Stroke: Factors Affecting Non-Contrast CT ASPECTS Reliability
Date
2018-06-27
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Abstract
The Alberta Stroke Program Early CT Score (ASPECTS) is a semiquantitative scale to assess the extent of early ischemic changes on non-contrast CT in acute ischemic stroke patients. This is crucial for prognostication and treatment selection. Recent studies have revealed significant heterogeneity in reported measures of inter-rater reliability in ASPECTS, and this thesis aims to investigate the reasons underlying this phenomenon from the perspective of clinicians’ cognitive processes. First, this work explores relevant topics in the psychology of image interpretation and, on this psychological basis, proposes potential causes of inconsistent ASPECTS reliability. Possible strategies to improve clinicians’ inter- and intra-rater reliability are also discussed. The effect of image reading context variables and rater expertise on ASPECTS inter-rater reliability was then investigated. Raters of different experience levels scored ASPECTS on baseline non-contrast CT scans under three prior-information conditions (NCCT only, NCCT with access to clinical information, NCCT with access to clinical information and multiphase CT angiography) and three reading-context conditions (high/low ambient light, time pressure). The results indicate that these variables have the capacity to affect ASPECTS reliability.
This work highlights the importance of acknowledging that medical image interpretation can be influenced by seemingly irrelevant external and internal factors like reading environment characteristics or physician-level variables. Giving more consideration to these variables in clinical and educational settings could improve the utility of tools like ASPECTS.
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ischemic stroke, medical decision making, medical image interpretation, computed tomography
Citation
Wilson, A. T. C. (2018). A Psychological Perspective on Image Interpretation in Acute Ischemic Stroke: Factors Affecting Non-Contrast CT ASPECTS Reliability (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/32229