Coronary View Simulator

You're at the controls of a virtual cath lab. The big square is the fluoro monitor; the room view on the right shows where the C-arm and table are.

1. Choose a view

• Pick a standard view from the list on the left (left coronary views at the top, right coronary below). The C-arm swings there and the injection side switches to match. Below the list, the current view is named with what it's best for.
• Or set your own angle with the C-arm sliders: Rotation from RAO to LAO, Angulation from caudal to cranial. Field of view zooms the image (a smaller field is a bigger image).

2. Inject and run a cine

• Left or Right under Injection chooses which coronary is filled with contrast, and which guide catheter is shown.
• Run cine plays one injection: contrast streams down the arteries over a few beats, then washes out. The heart beats during the run (switch this off with Heart motion).

3. Move the table

• Drag the image to pan the table, as you would to follow a vessel off the edge of the screen. The Table group has sliders for each direction and Centre table to reset.

4. Find out what you're looking at

• Hover over a vessel (or tap it on a touch screen) to name it, in the image or the room view.
• Under Display, Coronary tree overlays the whole tree, including the side that isn't injected; Chambers outlines the chambers and great vessels; Segment numbers shows the SCCT segments. Click a chamber's chip in the legend to show or hide it.
• Vessel labels, Guide catheter, Fine branches and Spine and ribs switch those parts of the picture on and off.

5. Look at the room

• Drag the room view to orbit around it and scroll to zoom. Close on heart moves the camera in on the heart inside the patient; Whole room goes back.

6. Try another heart

• The Heart menu at the top switches between real CT hearts: right-dominant, left-dominant, co-dominant, and one with a narrowed mid LAD. The page reloads with the new heart.

Tips

• Table and Display start collapsed: click a group's title to open or close it. Groups stay as you leave them, and closing the ones you aren't using gives the room view more space.
• Full screen, or press F, hides the browser around the simulator.
• To learn how views are named and how to read the image, see About this image.

Swing the C-arm and move the table, then turn on the coronary and chamber overlays to see which structures the projection is showing you.

Where the image comes from

The overlays

How the views are named, and how to read the image

• Views are named for where the detector sits. The X-ray tube is under the table, the detector is above the patient. LAO means the detector has swung over toward the patient's left; RAO, toward the right. Cranial tilts the detector toward the head, caudal toward the feet.
• The image is drawn as seen from the detector. In AP the head is at the top and the patient's left is on the screen's right, like looking down at the patient from the ceiling.
• RAO separates left from right along the AV groove. The AV groove (RCA and LCx) is seen edge-on, so the RCA looks like an "L" and the LAD runs along the front of the heart.
• LAO looks down the septum. The AV groove opens into a ring, so the RCA looks like a "C", and the LAD and LCx split to either side of the septum.
• Cranial views open the LAD and diagonals; caudal views open the LM, LCx and OMs. LAO caudal, the "spider", looks up the long axis from the apex onto the LM bifurcation.
• The fluoro image is computed from one real coronary CT (a right-dominant heart), by tracing X-rays through it at the current angle. Real hearts vary in orientation, so this heart's best angles can differ by a few degrees from the textbook ones.
• With the CT image, the anatomy overlay comes from that same CT: its coronary tree, chambers and great vessels. The aorta and pulmonary artery are cut off where the scan ends. If the CT can't load, a simplified, right-dominant model heart is used instead.

Credits and licences

A teaching tool, not a medical device. It is not for diagnosis, treatment or any other clinical use. Free and non-commercial.

• CT volumes: ImageCAS (Zeng A, Xu X, et al. Comput Med Imaging Graph 2023), CC BY-NC 4.0. Changed here: de-contrasted (blood pool clamped to 50 HU), resampled to 0.9 × 0.9 × 1 mm and cropped.
• Coronary labels and centrelines: ImageCAS-X (Bransby KM, et al. 2026, Zenodo), CC BY 4.0. Changed here: lumen labels resampled onto the CT, and small branches grown from the CT.
• Chambers and great vessels: segmented with TotalSegmentator heartchambers_highres (Wasserthal J, et al. Radiol Artif Intell 2023, doi:10.1148/ryai.230024). Meshes and data derived from these segmentations are published with the kind permission of Dr Jakob Wasserthal, Department of Radiology, Universitätsspital Basel.
• Software: Three.js (MIT). Fonts: Archivo Narrow, Inter and JetBrains Mono (SIL Open Font License).
• Made by Chiran Pandey, medical student at Humanitas University. Source code on GitHub.