Inclusion Criteria:

1. Age ≥ 18 years;
2. Preliminary diagnosis or symptoms indicating the presence or potential presence of a cerebral aneurysm;
3. Undergoing a non-contrast head MRA or contrast-enhanced head/neck CTA;
4. The patient or their legal representative is able and willing to sign an informed consent form.

Exclusion Criteria:

1. Other intracranial vascular diseases: moyamoya disease, arteriovenous malformations, arteriovenous fistulas, arterial occlusions, and arterial dissections;
2. History of intracranial arterial interventions: stent placement, partial aneurysm coil treatment, etc.;
3. Severe allergy to contrast agents or absolute contraindications to iodine-based contrast agents;
4. Renal insufficiency with elevated serum creatinine (greater than twice the upper normal limit);
5. MRI contraindications: pacemakers, claustrophobia, etc.;
6. Diseases or conditions that affect the quality of CTA/MRA images;
7. Inability to complete the study due to psychiatric disorders, cognitive, or emotional disturbances.

Note: The CTA sub-study does not include exclusion criterion 5; the MRA sub-study does not include exclusion criteria 3 and 4.