Inclusion criteria:

1. Age at least 18 years
2. Occlusion of ICA (cervical or intracranial), M1, or M2.
3. Symptom onset <24 hours
4. NIHSS <6
5. Not going for EVT at the time of enrollment (you are welcome to change treatment plan at any time, for any reason)

Exclusion criteria:

1. Contraindication to MRI (use MRI screening form)
2. Inability to lie flat 
3. Inability to obtain consent from patient or surrogate
4. Considered by the investigator to have a condition that precludes safe participation