Hemodynamic Study of In-Stent Stenosis(I) After Flow Diverter(F) Based on 3D-DSA(D) Combined With TCCD(T)

Inclusion Criteria: Age ≥ 18, male or non-pregnant female. Diagnosis of intracranial aneurysm confirmed by DSA (Digital Subtraction Angiography). Intracranial aneurysms treated with flow diverter (FD). DSA follow-up of at least 1 month. Exclusion Criteria: Secondary intracranial aneurysm cases: traumatic aneurysms, infectious aneurysms, or aneurysms associated with arteriovenous malformations (AVM) or vasculitis. Previously treated recurrent aneurysm or target aneurysm with craniotomy clipping surgery or other endovascular interventions. Aneurysms located at the distal end of the circle of Willis where TCCD (Transcranial Color-Coded Doppler) cannot be detected. Known familial clustering history. Expected survival less than 1 year. Preoperative clinical assessment with mRS (Modified Rankin Scale) score ≥ 3. Known allergy or contraindication to antiplatelet drugs, anticoagulants, contrast agents, anesthetics, nitinol memory alloy, platinum-tungsten alloy, or platinum-iridium alloy. Severe respiratory, hepatic, or renal disease (e.g., creatinine ≥ 3.0 mg/dL excluding dialysis) or coagulation disorders. Undergoing major surgery (e.g., limb fracture fixation, tumor resection, major organ surgery, etc.) within 30 days prior to signing informed consent or planned within 60 days after signing informed consent. Pregnant or lactating women, or women with a positive pregnancy test.