The patient's right is on the left of the image. Scroll to move through the slices, click two points to measure, and drag to pan. Pinch, or hold Ctrl or ⌘ and scroll, to zoom. From the keyboard, focus the image, move with the arrow keys (Shift for bigger steps) and press Enter at each end; + and − zoom and 0 resets. Escape clears; Page Up and Page Down change slice.
Measurements
A real, deidentified CTA of an infrarenal aneurysm, from an openly licensed collection. Measure it the same way as the phantoms.
Real scan: AVT case R6, CC BY 4.0.
This scan isn't scored yet: nobody has measured it by hand. Practise on it, and your numbers stay on this page.
From the Aortic Vessel Tree (AVT) collection, Radl et al., 2022, which builds on the RIDER Lung CT collection from The Cancer Imaging Archive. Cropped, averaged into 2 mm slices, and reduced to the HU range the viewer shows. Licence: CC BY 4.0. AVT on figshare · RIDER Lung CT on TCIA · CC BY 4.0
Lengths on a real scan run straight down the slices.
Diameters are outer wall to outer wall, thrombus included. On an oval neck, measure across the short axis. The neck runs from the lowest renal artery to where the aorta first widens by more than 10%.
Size a stent graft from your numbers. On a real scan only the diameters are graded, since there's no centreline to measure lengths along.
Sizing from Medtronic's public Endurant II/IIs sizing sheet (US, 12/2020) and the FDA-hosted IFU, for practice only. Codes are Medtronic's own. Not affiliated with Medtronic and not for clinical use; the instructions for use are the source of truth.
No caliper placed.
About this practice
Measure an abdominal aortic aneurysm the way you would before planning an endovascular repair: proximal neck diameter and length, the biggest sac diameter, and both common iliacs. The practice cases are synthetic CT phantoms built from exact geometry, so every answer is known to the tenth of a millimetre. The real scans are deidentified patient CT from openly licensed collections, credited where they're shown, and scored against answers measured by hand.
Medium: Standard phantoms and every real scan, no hints. Diameters pass within 2 mm and lengths within 5 mm. Points pay 50 to 100 for each measurement within tolerance and 50 for each device size that matches the table, with a time bonus on Hard, then scale by level. Stars count the measurements alone.