Norman Juchler1,2, Sabine Schilling3,4, Philippe Bijlenga5, Sandrine Morel5,6, Daniel Rüfenacht7, Vartan Kurtcuoglu8,9,10,11, Sven Hirsch12. 1. Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil, Switzerland. norman.juchler@uzh.ch. 2. The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland. norman.juchler@uzh.ch. 3. Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil, Switzerland. 4. Institute of Tourism ITW, Lucerne University of Applied Sciences and Arts, Lucerne, Switzerland. 5. Neurosurgery Division, Department of Clinical Neurosciences, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland. 6. Department of Pathology and Immunology, Faculty of Medicine, University of Geneva, Geneva, Switzerland. 7. Neuroradiology, SNRI, Klinik Hirslanden, Zurich, Switzerland. 8. The Interface Group, Institute of Physiology, University of Zurich, Zurich, Switzerland. 9. Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland. 10. National Center of Competence in Research, Kidney.CH, Zurich, Switzerland. 11. Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland. 12. Institute of Applied Simulation, Zurich University of Applied Sciences, Wädenswil, Switzerland. sven.hirsch@zhaw.ch.
Abstract
BACKGROUND: Morphological irregularity is linked to intracranial aneurysm wall instability and manifests in the lumen shape. Yet there is currently no consent on how to assess shape irregularity. The aims of this work are to quantify irregularity as perceived by clinicians, to break down irregularity into morphological attributes, and to relate these to clinically relevant factors such as rupture status, aneurysm location, and patient age or sex. METHODS: Thirteen clinicians and 26 laypersons assessed 134 aneurysm lumen segmentations in terms of overall perceived irregularity and five different morphological attributes (presence/absence of a rough surface, blebs, lobules, asymmetry, complex geometry of the parent vasculature). We examined rater agreement and compared the ratings with clinical factors by means of regression analysis or binary classification. RESULTS: Using rank-based aggregation, the irregularity ratings of clinicians and laypersons did not differ statistically. Perceived irregularity showed good agreement with curvature (coefficient of determination R2 = 0.68 ± 0.08) and was modeled very accurately using the five morphological rating attributes plus shape elongation (R2 = 0.95 ± 0.02). In agreement with previous studies, irregularity was associated with aneurysm rupture status (AUC = 0.81 ± 0.08); adding aneurysm location as an explanatory variable increased the AUC to 0.87 ± 0.09. Besides irregularity, perceived asymmetry, presence of blebs or lobules, aneurysm size, non-sphericity, and curvature were linked to rupture. No association was found between morphology and any of patient sex, age, and history of smoking or hypertension. Aneurysm size was linked to morphology. CONCLUSIONS: Irregular lumen shape carries significant information on the aneurysm's disease status. Irregularity constitutes a continuous parameter that shows a strong association with the rupture status. To improve the objectivity of morphological assessment, we suggest examining shape through six different morphological attributes, which can characterize irregularity accurately.
BACKGROUND: Morphological irregularity is linked to intracranial aneurysm wall instability and manifests in the lumen shape. Yet there is currently no consent on how to assess shape irregularity. The aims of this work are to quantify irregularity as perceived by clinicians, to break down irregularity into morphological attributes, and to relate these to clinically relevant factors such as rupture status, aneurysm location, and patient age or sex. METHODS: Thirteen clinicians and 26 laypersons assessed 134 aneurysm lumen segmentations in terms of overall perceived irregularity and five different morphological attributes (presence/absence of a rough surface, blebs, lobules, asymmetry, complex geometry of the parent vasculature). We examined rater agreement and compared the ratings with clinical factors by means of regression analysis or binary classification. RESULTS: Using rank-based aggregation, the irregularity ratings of clinicians and laypersons did not differ statistically. Perceived irregularity showed good agreement with curvature (coefficient of determination R2 = 0.68 ± 0.08) and was modeled very accurately using the five morphological rating attributes plus shape elongation (R2 = 0.95 ± 0.02). In agreement with previous studies, irregularity was associated with aneurysm rupture status (AUC = 0.81 ± 0.08); adding aneurysm location as an explanatory variable increased the AUC to 0.87 ± 0.09. Besides irregularity, perceived asymmetry, presence of blebs or lobules, aneurysm size, non-sphericity, and curvature were linked to rupture. No association was found between morphology and any of patient sex, age, and history of smoking or hypertension. Aneurysm size was linked to morphology. CONCLUSIONS: Irregular lumen shape carries significant information on the aneurysm's disease status. Irregularity constitutes a continuous parameter that shows a strong association with the rupture status. To improve the objectivity of morphological assessment, we suggest examining shape through six different morphological attributes, which can characterize irregularity accurately.
Entities:
Keywords:
Human ratings; Intracranial aneurysms; Irregularity; Quantitative morphology
Authors: Norman Juchler; Sabine Schilling; Philippe Bijlenga; Vartan Kurtcuoglu; Sven Hirsch Journal: Front Neurol Date: 2022-05-03 Impact factor: 4.003