Growth patterns of abdominal atherosclerotic calcified deposits from lumbar lateral X-rays

Abstract

The aim of this study is to investigate new methods for describing the progression of atherosclerosis based on novel information of the growth patterns of individual abdominal aortic calcifications (AACs) over time. Lateral X-ray images were used due to their low cost, fast examination time, and wide-spread use, which facilitates a large statistical model (n > 100) based on longitudinal data. The examined cohort consisted of 103 post-menopausal women aged 62.4 years (± 7.0 years) with an average number of AACs of (4.7 ± 8.0) at baseline. The subjects had X-ray images taken in 1992-1993 (baseline) and again in 2000-2001 (follow-up). The growth patterns of the individual AACs were derived based on registered baseline and follow-up images. Area, height, width, centre of mass position, and movement of the centre of mass, and upper and lower boundary of the matched AACs were measured. The AACs occurred first, mainly, on the posterior aortic wall. The AACs grew on average 41 in the longitudinal direction and 21 in the radial direction. A correlation of 0.48 (P < 0.001) between growth in width and height of the AACs was present. The centre of mass of the AACs moved 0.60 mm (P < 0.001) downstream in the aorta, on average. The growth patterns of AACs may give new insights into the progression of atherosclerosis. The downstream asymmetry in the growth patterns indicates variability in microscopic environments around the AACs.

Coronary artery plaque growth: A two‐way coupled shear stress–driven model

“…Our results showed higher stenosis growth in the distal portion of the plaque. Interestingly, this observation is in accordance with clinical evidence where preferential plaque growth in the downstream segment has been reported in abdominal and femoral arteries as well as coronary arteries . Higher smooth muscle cell concentration has been observed in the distal segment of plaques, which is hypothesized to contribute to higher growth in this region .…”

Distribution, size, shape, growth potential and extent of abdominal aortic calcified deposits predict mortality in postmenopausal women

“…Observer reproducibility, assessed by three radiologists scoring the same 16 x-rays, three times each, resulted in both inter- and intra- observer specificity of 0.99 and an area overlap dice score of 56% and 60% respectively, showing good reproducibility[ 26 ]. These annotations were used to compute the AC24 that ranges from 0 to 24 based on the length of the vertebral sections affected by calcified deposits[ 27 ].…”

Show, Attend and Detect: Towards Fine-Grained Assessment of Abdominal Aortic Calcification on Vertebral Fracture Assessment Scans

“…The distribution of AAC-24 scores in the dataset (see Table 1) is very challenging as it has severe class imbalance. Specifically, this distribution of zero scores is highly skewed for L1 and L2 perhaps because vascular calcification usually starts around L4 and L3 and then progresses upwards [12]. In terms of sequences for anterior segments, our data has 176 unique (out of 4 4 = 256 possible) combinations but only 29 of them appear more than 10 times.…”