Original ArticleMorphological Parameters Related to Aneurysm Wall Enhancement in Patients with Multiple Intracranial Aneurysms
Introduction
Because of the wide availability of advanced imaging techniques, unruptured intracranial aneurysms (UIAs) are common incidental findings, occurring in approximately 3% of the population.1, 2 The premise of reasonable decision making for treating UIAs is effective assessment of the risk of aneurysm rupture, which remains challenging, even though various attempts have been made.
Histopathological studies of animals and humans have indicated that inflammation plays a major role in aneurysm formation, growth, and rupture.3 The vessel wall magnetic resonance imaging (MRI) technique has developed into a capable noninvasive method for investigating aneurysm wall inflammation via aneurysm wall enhancement (AWE). The latter has been suggested to be highly related to aneurysm growth and rupture.4, 5, 6 Meanwhile, there is now increasing evidence suggesting that aneurysm morphology, including aneurysm shape, various size ratios, and flow angles, has a profound effect on aneurysm rupture and, given its simple and measurable nature, might be a feasible approach for predicting rupture in the clinical setting.7 However, the difference in aneurysm morphology between aneurysms with and without AWE, and how these 2 factors might interact to affect aneurysm rupture, requires further study.
Previous studies of aneurysm morphology have produced conflicting results. This may be due to the study design, in which the patients with ruptured aneurysms were compared with patients with unruptured aneurysms, differing in terms of such baseline characteristics as age, sex, and hypertension. In addition, the morphology of postruptured aneurysms might have changed dramatically, which is considered of little value in risk prediction.8 These confounding factors can be avoided by comparing the characteristics of UIAs of differing risk of rupture within the same patients. Therefore, in the present study, we compared morphological characteristics of aneurysms with or without AWE within the same patient with multiple UIAs to investigate the relationship between morphology and aneurysm wall characteristics.
Section snippets
Methods
The Institutional Review Board of Changhai Hospital approved this retrospective study and waived the requirement for informed consent. Patient information was anonymized and deidentified before analysis.
Results
The baseline and morphological characteristics of the 30 aneurysms in 14 patients (12 patients with 2 aneurysms and 2 patients with 3 aneurysms) are presented in Table 2. The patients ranged in age from 36 to 78 years, with a mean age of 57.7 years. Three patients were male, and 11 were female. Aneurysm size ranged from 2.5 mm to 15.9 mm, with a median size of 6.5 mm (interquartile range, 4.6–10.3 mm). The 30 aneurysms included 17 located in the internal carotid artery, 4 in the posterior
Discussion
In this study, we investigated the associations between morphological parameters and wall characteristics on vessel wall MRI in patients with multiple UIAs. The presence of AWE was highly associated with conventional risk factors for aneurysm rupture, especially aneurysm size and irregular shape. This finding may help expand our knowledge of the interaction of morphology and wall inflammation and its role in aneurysm rupture.
Depending on the completeness of the diagnostic procedures, multiple
Conclusions
The presence of AWE on vessel wall MRI was significantly correlated with conventional morphological rupture risk factors in multiple UIAs. Moreover, aneurysm size and irregular shape were independently associated with AWE. These results might suggest a relationship between AWE and aneurysm rupture and the potential use of AWE in clinical decision making for UIAs.
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Conflict of interest statement: This work was supported by the National Research and Development Project of Key Chronic Diseases (Grant 2016YFC1300700) and National Natural Science Foundation of China (Grants 81571118, 81701775, and 81771264).
Nan Lv and Haishuang Tang contributed equally to this work and should be considered co–first authors.