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Abstract
Background Intracranial aneurysm neck width tends to be overestimated when measured with three-dimensional rotational angiography (3DRA) compared with two-dimensional digital subtraction angiography (2D-DSA), owing to high curvature at the neck. This may affect morphological and hemodynamic analysis in support of treatment planning. We present and validate a method for extracting high curvature features, such as aneurysm ostia, during segmentation of 3DRA images.
Methods In our novel SURGE (segmentation with upsampled resolution and gradient enhancement) approach, the gradient of an upsampled image is sharpened before gradient-based watershed segmentation. Neck measurements were performed for both standard and SURGE segmentations of 3DRA for 60 consecutive patients and compared with those from 2D-DSA. Those segmentations were also qualitatively compared for surface topology and morphology.
Results Compared with the standard watershed method, SURGE reduced neck measurement error relative to 2D-DSA by >60%: median error was 0.49 mm versus 0.17 mm for SURGE, which is less than the average pixel resolution (~0.33 mm) of the 3DRA dataset. SURGE reduced neck width overestimations >1 mm from 13/60 to 5/60 cases. Relative to 2D-DSA, standard segmentations were overestimated by 16% and 93% at median and 95th percentiles, respectively, compared with only 6% and 37%, respectively, for SURGE.
Conclusion SURGE provides operators with high-level control of the image gradient, allowing recovery of high-curvature features such as aneurysm ostia from 3DRA where conventional algorithms may fail. Compared with standard segmentation and tedious manual editing, SURGE provides a faster, easier, and more objective method for assessing aneurysm ostia and morphology.
- Angiography
- Aneurysm
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information. Not applicable.
Statistics from Altmetric.com
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information. Not applicable.
Footnotes
Twitter @NMCancelliere, @RADIS_lab, @biomedsimlab
Contributors DEM developed the SURGE methodology, with input from NMC, VMP and DAS, and performed all 3D segmentations and data analysis. NMC, AR and VMP selected the clinical cases, and NMC and AR performed the 2D-DSA neck measurements. All authors contributed to the interpretation of the data, and the drafting and/or critical revision of the manuscript. All authors approved the final manuscript. DAS is responsible for the overall content as guarantor, and is also a member of JNIS Editorial Board.
Funding Natural Sciences & Engineering Research Council of Canada (RGPIN- 2018–04649).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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