Anatomic Characteristics of Intrapetrous Carotid Artery: A 3-Dimensional Segmentation Study on Head Computed Tomography Scan.

Abstract

The intrapetrous carotid artery (IPCA) is one of the most unexplored anatomic regions, and its 3-dimensional reconstruction in living subjects is still missing. This study aims to describe the IPCA on 3D models extracted from head computed tomography (CT) scans. The intrapetrous carotid artery was manually segmented on head CT scans of 100 healthy patients free from vascular and neurologic pathologies (50 men and 50 women; age range, 18-91 years). Angles of the posterior and anterior genu, diameter and length of the horizontal portion, and volume of the entire canal were calculated through 3D analysis software. Statistically significant differences according to sex and side were assessed through 2-way analysis of variance (P < 0.05). Correlation of each measurement with age was calculated as well. On average, the angles of the posterior and anterior genu were 120.1° ± 10.4° and 118.0° ± 10.0° in men and 119.5° ± 9.2° and 117.6° ± 10.3° in women, respectively, without statistically significant differences according to sex or side (P > 0.05). The average length and diameter of the horizontal part were, respectively, 25.5 ± 2.9 and 5.8 ± 0.8 mm in men and 24.0 ± 2.3 and 5.3 ± 0.8 mm in women. The volume of the IPCA was 0.941 ± 0.215 cm³ in men and 0.752 ± 0.159 cm³ in women. The length and diameter of the horizontal portion and the volume of the IPCA showed statistically significant differences according to sex (P < 0.05). No correlation with age was found. This study provides data concerning not only linear and angular measurements, but also volumes of the IPCA, which are useful in planning surgical interventions of the cranial base.