This study aims to conduct a comprehensive analysis by integrating clinical factors, aneurysm morphological characteristics, and factors reflecting pathophysiological processes (such as hemodynamic and radiomics features), in order to explore the hemodynamic mechanisms associated with the progression of intracranial dissecting aneurysms. Furthermore, artificial intelligence algorithms will be employed to develop and validate an intelligent risk prediction model for the progression and outcomes of intracranial dissecting aneurysms.

Inclusion Criteria:

1. Intracranial dissecting aneurysm clearly diagnosed by DSA and high-resolution MRI imaging (according to the imaging diagnostic criteria proposed in the Chinese Expert Consensus on Imaging Diagnosis of Intracranial Arterial Dissection)
2. patients managed with conservative treatment and follow-up
3. patients who agree and sign a written informed consent form

Exclusion Criteria:

1. Arteritis, fibromuscular dysplasia, iatrogenic or traumatic pseudoaneurysms
2. Contraindications to MRI examination (such as claustrophobia or metallic implants), or contraindications to cerebral angiography (such as iodine contrast allergy)
3. Dissecting aneurysms extending from the extracranial segment to the intracranial segment, or cases with concomitant intracranial atherosclerotic plaques in the affected vessels
4. Patients who refuse MRI examination
5. Patients with severe comorbid diseases and an expected survival time of less than 2 years due to these conditions
6. Patients without follow-up HR-MRI imaging for any reason

The target population consists of patients with intracranial artery dissection (IAD) who received care at the study institution between 2015 and 2025. Eligible participants are adults aged 18-80 years with IAD confirmed by both digital subtraction angiography (DSA) and high-resolution MRI (HR-MRI) according to the imaging diagnostic criteria proposed in the Chinese expert consensus on intracranial artery dissection. Participants are managed with conservative treatment and undergo follow-up, and they provide written informed consent. Key exclusions include arteritis, fibromuscular dysplasia, iatrogenic or traumatic pseudoaneurysm; contraindications to MRI or cerebral angiography (e.g., implanted metallic foreign bodies, claustrophobia, or iodinated contrast allergy); extracranial dissection extending intracranially or concomitant intracranial atherosclerotic plaque in the affected vessel; refusal of MRI; severe comorbidities with an expected survival of less than 2 years; or absence of

To protect patient privacy, the decision was made not to share the data.