The purpose of the bCAN study is to create a prospective collection of multimodal data and human samples, linked to the French Intracranial Aneurysm Registry (FRAN).

The aim of bCAN is to enable risk stratification of ruptured ICAs by redefining "intracranial aneurysm disease". The description of genotypically and phenotypically specific subgroups of cases will pave the way for improved patient management based on new diagnostic/prognostic strategies among AIC carriers, either in a familial context, or at the level of the general population.

The main objective of bCAN study is to build a predictive model of intracranial aneurysm phenotypes through the combination of information on genetic mutations, imaging findings and ICA rupture characteristics.

The secondary objectives of the bCAN study are (i) to study morphological characterization of ICA and vascular bifurcations, (ii) to deepen knowledge of genotype/clinical and biological phenotype relationships according to the genes identified in the different families, (iii) to research and validate the relationships between genotypes and phenotypes (including rupture) of ICA in a large population of sporadic ICA cases.

Inclusion criteria for sporadic ICA cases:

• Any adult patient consulting for a definite and typical bifurcation AIC authenticated on MRI and/or cerebral arteriography
• Aneurysm discovered less than a year ago, with initial imaging (MRI and/or CTA and DSA) available
• Written consent obtained for study participation
• Patient covered by a social security plan

Inclusion criteria for index and related cases (familial forms) of intracranial aneurysms (ICA):

• Index case: Any adult patient consulting for a definite and typical bifurcation ICA presenting at least one other case with ICA related (child, parent, brother, sister) detected by MRI with at least one Time of Flight (TOF) sequence.
• Family relatives: children, parents, brothers, sisters, of legal age, of patients with a family history of definite, typical bifurcation AIC (≥ 4 affected), Screening to be performed using MRI with at least a Time of Flight (TOF) sequence.
• Written consent to participate in the study
• Patient and relatives covered by a social security plan

Exclusion Criteria:

• Syndromic diagnosis known to cause ICA: Marfan syndrome, OSA with SMAD 3, Elhers Danlos syndrome type II and IV, Autosomal Dominant Cystic Fibrosis, Moya-Moya syndrome
• AIC with : Dissecting or fusiform, Associated with arteriovenous malformation, Blister-like, Mycotic
• Cerebral white matter pathology detected on MRI evoking : Col4a1 mutation
• Patient under guardianship or conservatorship
• Person under court protection
• Contraindication to an MRI scan