Aortic calcification: A postmortem CT validation study in a middle-aged population

Area of Science:

• Cardiovascular Imaging
• Histopathology
• Atherosclerosis Research

Background:

• Aortic calcification detected by computed tomography (CT) is a significant predictor of cardiovascular mortality, all-cause mortality, and cognitive decline.
• Previous studies have presented conflicting evidence regarding the precise location of aortic calcifications within the aortic wall layers (medial vs. intimal).
• Understanding the histological basis of CT-detected aortic calcifications is crucial for accurate interpretation and risk stratification.

Purpose of the Study:

• To histologically validate the detectability and precise location of aortic calcifications identified on computed tomography (CT) within the aortic wall.
• To correlate CT findings of aortic calcification with detailed histological analysis of postmortem aortic tissue samples.

Main Methods:

• Acquisition of postmortem CT images from 40 individuals.
• Collection and histological examination (hematoxylin and eosin, elastic van Gieson stain) of 170 aortic tissue samples from five distinct locations.
• Manual annotation of calcifications in the intima and media, with subsequent scoring of presence and morphology on CT images.

Main Results:

• Aortic calcifications were identified in 44% of the analyzed samples, with a higher prevalence in the abdominal aorta compared to the thoracic aorta.
• Overwhelmingly (99%), observed calcifications were located in the intimal layer, with only a small fraction showing medial involvement.
• CT imaging demonstrated an 85% concordance with histological findings for the presence of calcifications and high agreement for annularity (kappa=0.68).

Conclusions:

• Computed tomography (CT) reliably detects aortic calcifications, which are predominantly located in the intimal layer of the abdominal aorta in non-aneurysmatic and non-dissected aortas.
• The presence and annular characteristics of aortic calcifications can be accurately assessed using CT imaging.
• These findings support the use of CT for evaluating aortic calcification and its association with cardiovascular risk.