Computed tomography calcium quantification as a measure of atherosclerotic plaque morphology and stability.
OBJECTIVE
We examined the relationship between computed tomography (CT)-quantified calcium and histopathologic atherosclerotic plaque morphology and rupture.


METHODS
Seven aortae were harvested from autopsy cases. All were scanned, ex vivo, on a 16-slice CT scanner and CT calcium scores (CTCS) were calculated using a Siemens Calcium Scoring package. The aorta segments were physically cross sectioned at 3-mm intervals corresponding to CT reconstructions. Two pathologists evaluated the cross sections for histology calcium score (HCS), plaque fibrous cap disruption, overlying thrombus, internal hemorrhage, size, lipid content, and inflammation. CT and histology data were subsequently paired using predetermined quadrant and slice conventions.


RESULTS
Three hundred forty-nine aorta cross sections yielded 41 atherosclerotic plaques. Eleven plaques demonstrated plaque disruption and thrombosis and all contained calcium. CTCS was not significantly different between atherosclerotic plaques with and without evidence of disruption/thrombosis (F[1,30] = 1.525, P = 0.227). CT was 100% sensitive for nodular calcification, but only 56% (5 of 9 plaques) sensitive for non-nodular calcification. There was no significant relationship between CTCS and intraplaque hemorrhage, lipid content, inflammation, and plaque size (P = 0.179, P = 0.230, P = 0.314, and P = 0.054). There was significant correlation between CTCS and HCS (Pearson coefficient = 0.535; P < 0.01).


CONCLUSIONS
Calcium quantity does not appear to predict plaque morphology or likelihood of rupture. CT has lower sensitivity for non-nodular compared with nodular calcification.
Pham
Peter H
PH
Department of Radiological Sciences, David Geffen School of Medicine at UCLA, University of California-Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095-1721, USA.
Rao
Dinesh S
DS
Vasunilashorn
Fah
F
Fishbein
Michael C
MC
Goldin
Jonathan G
JG
D002114:Calcinosis / Q000000981:diagnostic imaging* / Q000473:pathology; D002118:Calcium / Q000032:analysis*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D003331:Coronary Vessels / Q000473:pathology*; D006801:Humans; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D002118:Calcium