The goal of this observational study is to understand acute anterior circulation large artery occluded minor stroke (LVO-MIS) evolution using magnetic resonance spectroscopic imaging evaluation. The main questions it aims to answer are:

1. Neurometabolic predictors of early neurological deterioration and functional outcome;
2. Temporal and spatial dynamic changes of the neurometabolites from the acute stage (within 24 hours), through the subacute stage (5-7 days), to the chronic stage (90 days);
3. Temporal and spatial dynamic changes of the neurotransmitters GABA, glutamate, and glutamine from the acute stage to the chronic stage;
4. Brain regions exhibiting changes in whole-brain metabolic network connectivity.

Minor acute ischemic stroke (AIS) is a common medical condition accounting for more than 50% of AIS. Of the patients with minor AIS, 28.3% are unable to discharge home, and 28.5% cannot walk independently. Although most patients with large vessel occlusion (LVO) strokes and mild symptoms have good clinical outcomes, individuals with early neurological worsening tend to do poorly despite rescue thrombectomy. Therefore, it would be ideal to understand the factors associated with acute neurological deterioration ≥4 NIHSS points among this population to potentially triage higher risk individuals to upfront endovascular therapy.

The main goal of this study was to investigate the spatial and temporal changes of neurometabolite concentrations in patients with acute mild ischemic stroke with large vessel occlusion (LVO-MIS) and to assess the extent to which the combination of all neurometabolite signals measured by 3D-MRSI could discriminate between early neurologic deterioration (END) and non-END patients.

Patients who are older than 18 years of age diagnosed with acute mild ischemic stroke with large vessel occlusion (LVO-MIS) within 24 hours of onset will be enrolled into the study. MRSI will be performed in enrolled stroke patients from the acute stage (within 24 hours), through the subacute stage (5-7 days), to the chronic stage (90 days). Higher resolution 3D MRSI scans were performed using SPICE. The acquisition parameters were as follows: TR = 160 msec, TE = 1.6 msec, spatial resolution = 2.0 × 3.0 × 3.0 mm3, FOV = 240 × 240 × 120 mm3, scan time = 18:35 min.

Inclusion Criteria:

1. Adult (age ≥ 18 years) patients presenting with symptoms consistent with acute ischemic stroke due to occlusion of the intracranial internal carotid artery and/or M1 or M2 segment of the middle cerebral artery;
2. Patients with mild symptoms at admission (National Institutes of Health Stroke Scale (NIHSS)<6);
3. Baseline multimodal-CT imaging, including NCCT, CTA and CTP, performed at the trial-site hospital;
4. Time from symptom onset or last known normal to enrollment is less than 24 hours;
5. Patient or legal representative willing to comply with protocol requirements and data collection procedures, understand and sign informed consent.

Exclusion Criteria:

1. A pre-incident mRS ≥ 1 point before onset;
2. Previous clear history of cerebral infarction, cerebral hemorrhage, brain tumor and other diseases that affect cerebral metabolism;
3. Intolerance or non-cooperation with magnetic resonance examination;
4. Severe cardiac, hepatic, renal impairment or other systemic serious advanced diseases;
5. Pregnancy or lactation;
6. Life expectancy is less than 3 months;
7. Other conditions that, in the opinion of the investigator, are not suitable for participation in this study or may pose a significant risk to the patient (such as inability to understand and/or comply with study procedures and/or follow-up due to psychiatric disorders, cognitive or emotional disorders).

Patients who are older than 18 years of age diagnosed with acute mild ischemic stroke with large vessel occlusion (LVO-MIS) within 24 hours of onset will be enrolled into the study.