List of the investigated geometric parameters, their descriptions, and median relative uncertainties (MRUs)
Parameter group | Parameter name, unit (exemplary reference) | Parameter abbreviation | Short description | MRU |
Size | Height, mm19 | H | Maximum perpendicular distance from the neck plane to the aneurysm surface | 0.140 |
Maximum dimension, mm32 | Lmax | Maximum distance between two points on the aneurysm surface | 0.157 | |
Maximum height, mm15 | Hmax | Maximum distance between the centroid of the neck and the aneurysm surface | 0.123 | |
Maximum diameter, mm17 | Dmax | Maximum neck plane-parallel distance between two points on the aneurysm surface | 0.169 | |
Bulge height, mm19 | Hb | Distance between the neck plane and the maximum diameter | 0.373 | |
Surface area, mm215 | A | Surface area of the aneurysm | 0.215 | |
Convex hull surface area, mm215 | ACH | Surface area of the aneurysm’s convex hull | 0.277 | |
Minimal bounding sphere surface area, mm233 | AMBS | Surface area of the aneurysm’s minimal bounding sphere | 0.305 | |
Closed surface area, mm2 | Aclosed | Surface area of the neck-closed aneurysm | 0.283 | |
Volume, mm315 | V | Volume of the neck-closed aneurysm | 0.392 | |
Convex hull volume, mm315 | VCH | Volume of the aneurysm’s convex hull | 0.399 | |
Minimal bounding sphere volume, mm333 | VMBS | Volume of the aneurysm’s minimal bounding sphere | 0.451 | |
Neck | Minimum neck diameter, mm17 | Dneck,min | Minimum distance between two opposite points on the neck perimeter | 0.306 |
Maximum neck diameter, mm34 | Dneck,max | Maximum distance between two points on the neck perimeter | 0.348 | |
Neck perimeter, mm19 | Pneck | Perimeter of the aneurysm neck | 0.374 | |
Equivalent neck diameter, mm19 | Dneck,equiv | Hydraulic diameter of the aneurysm neck | 0.276 | |
Neck area, mm219 | Aneck | Area of the aneurysm neck | 0.593 | |
Elliptical neck area, mm2 | Aneck,elliptical | Neck area calculated as the product of the minimum and maximum neck diameter | 0.650 | |
Non-dimensional | Aspect ratio34 | AR | Ratio of height to maximum neck diameter | 0.293 |
Equivalent aspect ratio19 | eAR | Ratio of height to equivalent neck diameter | 0.326 | |
Bottleneck factor19 | BF | Ratio of maximum diameter to maximum neck diameter | 0.201 | |
Bulge location19 | BL | Ratio of bulge height to height | 0.301 | |
Nonsphericity index15 | NSI | Normalised ratio of volume to surface area relative to a hemisphere | 0.108 | |
Aneurysm volume to bounding sphere volume33 | AVSV | Ratio of volume to minimal bounding sphere volume | 0.173 | |
Aneurysm surface area to bounding sphere area33 | AASA | Ratio of surface area to minimal bounding sphere surface area | 0.095 | |
Undulation index15 | UI | 1 minus the ratio of volume to convex hull volume | 0.709 | |
Ellipticity index15 | EI | Normalised ratio of convex hull volume to convex hull surface area relative to a hemisphere | 0.051 | |
Curvature | Mean of mean curvature, mm−119 | MAA | Surface average of local mean curvature | 0.136 |
Mean of absolute mean curvature, mm−1 | absMAA | Surface average of the magnitude of the local mean curvature | 0.133 | |
SD of mean curvature, mm−1 | MSD | SD of the local mean curvature | 1.011 | |
High mean curvature, %33 | HMC | Relative increase of the mean of absolute mean curvature over the mean curvature of the minimal bounding sphere | 0.396 | |
L2-norm of mean curvature19 | MLN | Scale invariant measure of surface irregularity, uses mean curvature | 0.150 | |
Mean of Gaussian curvature, mm−219 | GAA | Surface average of local Gaussian curvature | 0.344 | |
Mean of absolute Gaussian curvature, mm−2 | absGAA | Surface average of the magnitude of the local Gaussian curvature | 0.485 | |
SD of Gaussian curvature, mm−2 | GSD | SD of the local Gaussian curvature | 1.798 | |
High Gaussian curvature, %33 | HGC | Relative increase of the mean of absolute Gaussian curvature over the Gaussian curvature of the minimal bounding sphere | 0.822 | |
L2-norm of Gaussian curvature19 | GLN | Scale invariant measure of surface irregularity, uses Gaussian curvature | 0.545 |
Note that terminology and implementation in the references might differ subtly. Derived and modified from tables 1–5 from Goubergrits et al,14 used under Creative Commons Attribution License (CC BY 4.0). The CC BY 4.0 license text is available at https://creativecommons.org/licenses/by/4.0/.
MRU, median relative uncertainty.