This clinical research, aims to investigate the uptake of [18F]FBFP, a Sigma-1 receptor (Sig 1R) PET imaging agent, in stroke participants, compare differences with healthy controls, and evaluate its diagnostic efficacy, providing objective basis for clinical diagnosis and treatment.

The study will recruit 30 stroke participants (with specific inclusion criteria for unilateral ICA stenosis cases) and 20 gender- and age-matched healthy controls from January 2025 to December 2026. Exclusion criteria cover various neurological and systemic diseases that may affect results, as well as conditions preventing cooperation with examinations.

No intervention measures are involved. Follow-ups will be conducted at 6 and 12 months to collect clinical data and observe neurological symptom progression. Key measurements include clinical information (via questionnaires and scales like NIHSS and mRS) and PET/MR imaging data (analyzed using PMOD software to calculate SUVmean and uptake differences with cerebellar cortex as reference).

Statistical analysis will use SPSS 21.0, applying descriptive statistics, t-test, ANOVA, regression models, ROC curves, etc., with P < 0.05 as significant. Safety evaluation notes PET/MR radiation dose (3-5mSv) is much lower than the safe threshold.

Participant protection includes ethical approval, informed consent, voluntary participation, risk disclosure, no fees for related exams, and privacy protection. The research team and institution have sufficient resources and qualifications, with outputs including a clinical research cohort and a high-quality paper.

Inclusion Criteria:

1. Angiography diagnosis shows unilateral anterior circulation head and neck artery stenosis with a diameter reduction of>70%, and there is no stenosis in the contralateral anterior circulation or bilateral posterior circulation with a diameter reduction of>50%;
2. Transient ischemic attack or ischemic stroke that must have occurred within the past 12 months in the affected vascular area, with the most recent attack lasting more than 3 weeks;
3. MRI shows no new intracranial infarction lesions;
4. No previous infarction lesions in the pontine area;
5. Either PET/MR blood flow or metabolic imaging shows reduced blood flow and metabolism in the affected hemisphere, with a reduction rate exceeding 10% compared to the contralateral region;
6. Subjects and informants can complete relevant examinations and follow-up work;
7. The subject or their authorized representative signs the informed consent form.

Exclusion Criteria:

1. Poor image quality due to head movement and other reasons during the scanning process.
2. There are other neurological disorders that can cause brain dysfunction, such as depression, brain tumors, Parkinson's disease, metabolic encephalopathy, encephalitis, multiple sclerosis, epilepsy, traumatic brain injury, normal intracranial pressure hydrocephalus, etc.
3. There are other systemic diseases that can cause cognitive impairment, such as liver dysfunction, kidney dysfunction, thyroid dysfunction, severe anemia, folate and vitamin B12 deficiency, special infections (such as syphilis, HIV), alcohol and drug abuse, etc.
4. Existence of mental and neurological developmental delay.
5. There are other known diseases that may cause cognitive impairment.
6. Individuals with severe visual and hearing impairments, claustrophobia, and other conditions who cannot cooperate with MRI examinations.
7. Suffering from diseases that prevent cooperation in completing cognitive examinations.
8. Refusal to sign informed consent form during baseline period -