MPSI Category | Corresponding AHA lesion types (modified) | Description | Level of vulnerability |
---|---|---|---|
0 | I or II | Normal or nearly normal wall. | Very stable |
1 | III | Moderate intimal thickening, no extracellular lipid, calcification or significant inflammation. | Stable |
2 | IV/V with less than 30% NC by area; or VII; or VIII | Advanced lesion with small necrotic core (<30% of plaque size), or can be fibrotic or calcified, thick fibrous cap (> 200 μm). | Slightly unstable |
3 | IV/V with 30–40% NC by area | Advanced lesion with Moderate lipid core (30–40% of plaque size) and fibrous cap (150–200 μm). | Moderately unstable |
4 | IV/V with > 40% NC by area; or VI | Advanced lesion with a very large necrotic core (>40%), thin fibrous cap (<150 μm), or with fibrous cap rupture, ulceration, or intraplaque hemorrhage. | Very unstable |