Multimodal Neuroimaging in the Selection of Acute Ischemic Stroke (AIS) Patients to Endovascular Treatment (EVT)

To study the feasibility and usefulness of multimodal MR compared to multimodal CT to select patients with acute ischemic stroke and favorable clinical outcome after mechanical thrombectomy. The specific objectives are to compare (1) the door-picture time and door-groin puncture time, (2) the rate of patients with acute stroke selected for endovascular treatment and (3) the safety and clinical response after thrombectomy between the two groups selected according to the imaging modality.

Methodology: Single-center, randomized 1:1 and stratified by age and NIHSS study of consecutive patients with suspected acute ischemic stroke. Occlusion site, ischemic volume (core) and perfusion volume will be studied by an automated perfusion system (RAPID software) in both neuroimaging groups. Mechanical thrombectomy criteria will be basically based on the presence of a Large Vessel Occlusion (LVO) and a volume of core lower than 70cc in the Cerebral Blood Flow (CBF) or Diffusion Weighted Image (DWI) sequences. Modified Rankin scale at 90 days and the rate of intracranial hemorrhage and mortality will be considered as variables of response.

In acute ischemic stroke, arterial occlusion lead to a brain ischemia that will progress to brain death of the ischemic area if the clot is not rapidly removed. Advanced neuroimaging can help us to distinguish between the irreversible injury brain parenchyma or core and the potential reversible ischemic tissue or penumbra. Multimodal neuroimaging techniques (MR and CT) have been developed in order to distinguish between core and penumbra areas and have been used to select patients in most of the last randomized clinical trials that have demonstrated the benefit of endovascular treatment. There is no agreement about which multimodal technique offers a better information to select patients for endovascular treatment.

The main aim is to study the feasibility and usefulness of multimodal MR compared to multimodal CT to select patients with acute ischemic stroke and favorable clinical outcome after mechanical thrombectomy.

The specific objectives are: Primary: to confirm no differences in long-term clinical outcome in patients with acute ischemic stroke and in those treated with endovascular therapy selected by multimodal CT or MR; and Secondary: (1) compare the feasibility of both techniques in this setting, (2) the door-picture time and door-groin puncture time of both techniques, (3) the safety of both techniques (sICH and in-hospital pneumonia) Methodology: Single-center, randomized (1:1) and stratified by age and NIHSS study of consecutive patients with acute ischemic stroke. Occlusion site, ischemic volume (core) and perfusion volume will be studied by an automated perfusion system (RAPID software) in both neuroimaging groups. Mechanical thrombectomy criteria will be basically based on the presence of an intracranial LVO occlusion and a volume of core lower than 70cc in the CBF or DWI sequences. Modified Rankin scale at 90 days and the rate of intracranial hemorrhage and mortality will be considered as variables of response.

Eligibility Criteria:
Inclusion Criteria:

1. Age ≥ 18 years old
2. Without previous functional dependency evaluated by modified Rankin Score ≤2
3. Regarding stroke severity (NIHSS≥ 6)
4. Time from symptoms onset \<24 hours

Exclusion Criteria:

1. Clinical suspicion of vertebrobasilar occlusion (brainstem symptoms)
2. MR contraindication or lack of concomitant availability of one or both neuroimaging techniques
3. Severe kidney failure