Defining a master curve of abdominal aortic aneurysm growth and its potential utility of clinical management

•A total of 21 morphological parameters obtained longitudinal CT scan images was computed•The growth rate of all geometrical measurements and their correlation analysis were investigated in terms of non-surgical management of AAA.•AAA volume expansion rates were highly correlated with thrombus accumulation rates.•Among all geometrical parameters, the master curve of spherical diameter performed best, predicting the diameter.•This measure provides useful information about the evolution of aneurysm size and may be clinically helpful. The maximum diameter measurement of an abdominal aortic aneurysm (AAA), which depends on orthogonal and axial cross-sections or maximally inscribed spheres within the AAA, plays a significant role in the clinical decision making process. This study aims to build a total of 21 morphological parameters from longitudinal CT scans and analyze their correlations. Furthermore, this work explores the existence of a “master curve” of AAA growth, and tests which parameters serve to enhance its predictability for clinical use. 106 CT scan images from 25 Korean AAA patients were retrospectively obtained. We subsequently computed morphological parameters, growth rates, and pair-wise correlations, and attempted to enhance the predictability of the growth for high-risk aneurysms using non-linear curve fitting and least-square minimization. An exponential AAA growth model was fitted to the maximum spherical diameter, as the best representative of the growth among all parameters (r-square: 0.94) and correctly predicted to 15 of 16 validation scans based on a 95% confidence interval. AAA volume expansion rates were highly correlated (r=0.75) with thrombus accumulation rates. The exponential growth model using spherical diameter provides useful information about progression of aneurysm size and enables AAA growth rate extrapolation during a given surveillance period.