SHS_543051 KEOB FSTA 12062

Imaging of Collaterals in Acute Stroke (iCAS)

Stroke is caused by a sudden blockage of a blood vessel that delivers blood to the brain. Unblocking the blood vessel with a blood clot removal device restores blood flow and if done quickly may prevent the disability that can be caused by a stroke.

However, not all stroke patients benefit from having their blood vessel unblocked.

The aim of this study is to determine if special brain imaging, called MRI, can be used to identify which stroke patients are most likely to benefit from attempts to unblock their blood vessel with a special blood clot removal device. In particular, we will assess in this trial whether a noncontrast MR imaging sequence, arterial spin labeling (ASL), can demonstrate the presence of collateral blood flow (compared with a gold standard of the angiogram) and whether it is useful to predict who will benefit from treatment.

Inclusion Criteria

Age 18 and older
Clinical diagnosis of ischemic stroke and an associated score on the NIHSS of 5 or more points
Planned to undergo (or has undergone) intra-arterial (IA) thrombectomy and/or thrombolysis for acute hemispheric stroke. (Either as primary therapy or as adjuvant therapy following intravenous tPA treatment)
Planned to undergo or has undergone an MR brain scan including MR perfusion imaging (ASL & bolus PWI) and MR angiography of the circle of Willis prior to IA therapy
Intra-arterial thrombectomy can be started within 90 minutes of completion of the MR perfusion scan and within 24 hours of symptom onset (Start of IA therapy is defined as the time of insertion of the femoral artery sheath; Time of brain scan is defined as the time that the scan is completed)
Able to obtain informed consent

Exclusion Criteria

Any pre-existing illness resulting in a modified Rankin Scale Score of 2 or higher prior to the qualifying stroke
Creatinine clearance < 40 ml/min based on the NIDDK four-variable MDRD method (non-weight based)
Documented allergy to MR contrast agent
MRI contraindications (pacemaker, etc.)
Bart Keogh, M.D.
Stanford University
xCheryl Kelly
  • Swedish Medical Center