Irregular Pulsation of Intracranial Aneurysm Detected by Four-Dimensional CT Angiography and Associated With Small Aneurysm Rupture: A Single-Center Prospective Analysis.

Huilin Zhao,Jiafeng Zhou,Yongchun Chen,Qinhua Guo,Boli Lin,Bing Zhao,Jieqing Wan,Shenghao Ding,Yaohua Pan

doi:10.3389/fneur.2022.809286

Abstract

ObjectivesPredicting the risk of rupture of small intracranial aneurysms remains challenging. The irregular pulsation of aneurysms detected by four-dimensional CT angiography (4D-CTA) could be an imaging marker of aneurysm vulnerability. We aimed to investigate the association of irregular pulsation with small aneurysm rupture.Materials and MethodsThis was a prospective study on intracranial aneurysms detected by 4D-CTA from October 2017 to January 2020. A total of 242 consecutive patients with 316 aneurysms were enrolled. Irregular pulsation was defined as a temporary focal protuberance on more than 3 consecutive frames of the 20 phases in the RR interval. Small aneurysms were defined as those <7 mm. Univariate and multivariate analyses were performed to determine the independent predictors of small aneurysm rupture.ResultsA total of 169 patients with 217 small intracranial aneurysms were included. Fourteen (6.5%) of the aneurysms had ruptured, and 77 (35.5%) had irregular pulsation. There were no significant differences in age, sex, hypertension, smoking, diabetes, drinking, or hyperlipidemia between the ruptured and unruptured aneurysm groups. The univariate analysis showed that smaller vessel size (p = 0.008), larger size ratio (p = 0.003), larger aspect ratio (p = 0.006), larger flow angle (p = 0.001), large vessel angle (p = 0.004), middle cerebral artery aneurysms (p = 0.046), anterior cerebral artery/posterior communicating artery/posterior circulation aneurysm (p = 0.006), irregular aneurysm (p = 0.001), and t presence of irregular pulsation (p = 0.001) were associated with small aneurysm rupture. The multivariate analysis showed that the presence of irregular pulsation (p = 0.003), anterior cerebral artery/posterior communicating artery/posterior circulation aneurysms (p = 0.014), and larger flow angle (p = 0.006) was independently associated with aneurysm rupture. Multivariate analysis of predictors of the irregular pulsation of small aneurysms showed that the aneurysm rupture (p = 0.022), irregular aneurysm (p < 0.001), and large size ratio (p = 0.005) were independently associated with the presence of irregular pulsation.ConclusionsThe ruptured small aneurysms more often had irregular pulsation. The irregular pulsation was independently associated with aneurysm rupture and may help evaluate the risk of rupture of small intracranial aneurysms.

Highlights

Unruptured intracranial aneurysms (UIAs) are increasingly being detected as non-invasive imaging modalities are commonly used
We found that irregular pulsation, non-carotid artery aneurysm, and larger flow angle were independently associated with small aneurysm rupture
Our findings suggest that the irregular pulsation detected by 4D-CTA could be used to potentially evaluate the risk of small aneurysm rupture in a clinical setting

Summary

Introduction

Unruptured intracranial aneurysms (UIAs) are increasingly being detected as non-invasive imaging modalities are commonly used. Majority of patients with small UIAs have low risk of rupture [1, 3, 4]. Small aneurysms have a high proportion in patients with subarachnoid hemorrhage (SAH) [5, 6]. There is a controversy regarding which small UIAs can be left untreated, or which aneurysms are needed to be treated [4, 7]. Conventional morphological parameters, such as aneurysm irregularity, aneurysm location, and size ratio, are associated with aneurysm rupture [4, 6]; these parameters are confounding and controversial [8]. Recent studies have reported that irregular pulsation observed by 4D-CTA could be a novel imaging marker of aneurysm vulnerability [12,13,14]

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