(A) Ruptured walls have significantly lower calcification fraction than unruptured walls in human IAs, p = 0.005, 0.006, 0.029 for inner, middle and outer thirds of the wall, respectively (n = 50). (B) Ruptured IAs are limited to either having no calcifications or “non-atherosclerotic” calcifications (Type I and Type II walls). No ruptured IAs display “atherosclerotic” calcifications (Type III walls) (p = 0.027*). (C) with micro or meso-calcifications, or Type II walls only with micro-calcifications (n=65), whereas unruptured walls possess all wall types.