Cardiac segments are the AHA 17-segment map of the left ventricle: a shared language for wall motion, perfusion, and coronary territory. It is not a chamber mask. It is not a volume or an ejection-fraction number.
If you meant label LV / RV / myocardium on cine MRI or CT → heart segmentation. If you meant bronchopulmonary segments on chest CT → lung segments on CT. If you meant how you draw any mask → medical image segmentation. If you meant mandible on a panoramic → mandible segmentation from panoramic X-ray.
PYCAD builds custom web DICOM viewers and imaging models. It does not ship a cardiology workstation or a 17-segment scoring product.
What the 17-segment model is
The American Heart Association statement (Cerqueira et al., Circulation 2002) standardized left-ventricle nomenclature for echo, SPECT, PET, and CMR. The LV is cut into three short-axis thirds — basal, mid-cavity, apical — plus an apical cap. Basal and mid have six segments each. Apical has four walls plus the cap. Segments are numbered 1–17, clockwise as viewed from the apex.
A report that says “akinesis in 7 and 13” is naming mid-anterior and apical-anterior. That is a coronary-territory sentence, not a chamber-volume sentence. Chamber masks (the pixels you measure EF from) live on heart segmentation.
| # | Name | Level | Typical coronary territory |
|---|---|---|---|
| 1 | Basal anterior | Basal | LAD |
| 2 | Basal anteroseptal | Basal | LAD |
| 3 | Basal inferoseptal | Basal | RCA |
| 4 | Basal inferior | Basal | RCA |
| 5 | Basal inferolateral | Basal | LCx or RCA (dominance) |
| 6 | Basal anterolateral | Basal | LCx |
| 7 | Mid anterior | Mid | LAD |
| 8 | Mid anteroseptal | Mid | LAD |
| 9 | Mid inferoseptal | Mid | RCA |
| 10 | Mid inferior | Mid | RCA |
| 11 | Mid inferolateral | Mid | LCx or RCA (dominance) |
| 12 | Mid anterolateral | Mid | LCx |
| 13 | Apical anterior | Apical | LAD |
| 14 | Apical septal | Apical | LAD |
| 15 | Apical inferior | Apical | RCA |
| 16 | Apical lateral | Apical | LCx |
| 17 | Apical cap | Apex | Usually LAD; variable |
Territories are typical, not a law. A dominant RCA can own the inferolateral wall. A wrap-around LAD can own more of the apex. The map is how teams talk; the angiogram is how they confirm the vessel.
What you score on a segment
Wall-motion scores (normokinesis / hypokinesis / akinesis / dyskinesis) and perfusion scores (normal / reversible / fixed) are assigned per segment, then rolled into a bullseye. Echo is the first-line, real-time look. CMR is the tissue look (late gadolinium, T1/T2). SPECT / PET is the perfusion and metabolism look. None of those is a chamber mask.
A myocardial infarction that lights up segments 7, 8, 13, and 14 is an anterior / septal, LAD-territory story. That sentence is why the model exists. Surgical or congenital anatomy that needs a whole-heart mesh is a different job — that is the mask page.
What this page is not
- Not heart segmentation. LV / RV / myocardium pixels, EF, scar volume → heart segmentation.
- Not lung segments. S1–S10 on chest CT → lung segments on CT.
- Not a methods catalogue. Threshold / U-Net as idea → medical image segmentation.
- Not a cardiology product. No PYCAD bullseye scorer.
If a viewer has to show the bullseye next to the cine, that is the imaging piece. Case studies.