Three-Dimensional Geometry of the Human Carotid Artery

Abstract

Accurate characterization of carotid artery geometry is vital to our understanding of the pathogenesis of atherosclerosis. Three-dimensional computer reconstructions based on medical imaging are now ubiquitous; however, mean carotid artery geometry has not yet been comprehensively characterized. The goal of this work was to build and study such geometry based on data from 16 male patients with severe carotid artery disease. Results of computerized tomography angiography were used to analyze the cross-sectional images implementing a semiautomated segmentation algorithm. Extracted data were used to reconstruct the mean three-dimensional geometry and to determine average values and variability of bifurcation and planarity angles, diameters and cross-sectional areas. Contrary to simplified carotid geometry typically depicted and used, our mean artery was tortuous exhibiting nonplanarity and complex curvature and torsion variations. The bifurcation angle was 36 deg ± 11 deg if measured using arterial centerlines and 15 deg ± 14 deg if measured between the walls of the carotid bifurcation branches. The average planarity angle was 11 deg ± 10 deg. Both bifurcation and planarity angles were substantially smaller than values reported in most studies. Cross sections were elliptical, with an average ratio of semimajor to semiminor axes of 1.2. The cross-sectional area increased twofold in the bulb compared to the proximal common, but then decreased 1.5-fold for the combined area of distal internal and external carotid artery. Inter-patient variability was substantial, especially in the bulb region; however, some common geometrical features were observed in most patients. Obtained quantitative data on the mean carotid artery geometry and its variability among patients with severe carotid artery disease can be used by biomedical engineers and biomechanics vascular modelers in their studies of carotid pathophysiology, and by endovascular device and materials manufacturers interested in the mean geometrical features of the artery to target the broad patient population.

Age and disease-related geometric and structural remodeling of the carotid artery

“…Segmentations, including the outer arterial wall and luminal contours, were obtained using a combination of thresholding and region-growing techniques. 12,13 Because some plaques had tissue densities similar to the surrounding tissue, a vascular surgeon assisted in all segmentations to ensure proper boundary selection.…”

“…The angle of the carotid bifurcation was measured between the ICA and external carotid artery in three dimensions. 12 Twist was assessed as rotation of the bulb around the arterial axis, and the planarity angle was measured between the out-of-plane components of the CCA and ICA centerlines (Fig 2).…”

Variation in the Caudal Branches of the External Carotid Artery: Comparison of Sex and Side

“…Previous studies have shown that multiple ECA branching patterns exist (Gupta et al 2014, Hayashi et al 2005, Kamenskiy et al 2012, Kitagawa 1993, Klosek and Rungruang 2008, Lo et al 2006, LuČev et al 2000, Natsis et al 2011, Ozgur, Govsa, and Ozgur 2008, Sanjeev et al 2010, Shintani et al 1999, Toni et al 2004, Vázquez et al2009, Yonenaga et al 2011, Zümre et al 2005. Classic textbook representations of the ECA and the origins of its eight branches vary significantly depending on source (Drake, Vogl, and Mitchell 2005, Gilroy et al 2008, Moore, Dalley, and Agur 2009, Netter 2010.…”

“…The inability to anticipate the precise location of the origin and course of blood vessels make surgical procedures potentially dangerous; thus, arteries exhibiting unpredictable patterns increase the likelihood of iatrogenic injury (Chleborad and Dawson 1990, Malnar et al 2010, Mangla and Sclafani 2008. Additionally, while arterial variation often goes unrecognized throughout an individual's life, pathological processes such as vascular disease render these variations important with regard to effective clinical intervention (Gluncic 2001, Kamenskiy et al 2012. Emergency surgical intervention is often necessary in instances of neck trauma.…”

Patient-specific system for prognosis of surgical treatment outcomes of human cardiovascular system

“…The basis of the current study is hemodynamics theory of vessel wall damage, the essence of which lies in determination of hemodynamic conditions which affect development of pathological states [6][7][8][9][10] . Modeling of blood flow in varios vessels within the aforementioned theory is demonstrated in many works [2][3][4][5][11][12][13][14][15][16][17] . But the problem of pathological tortuosity of arteries is poorly presented in literature.…”