All consecutive acute ischemic stroke patients with large-vessel occlusion treated by mechanical thrombectomy at a single academic institution between August 2002 and October 2012 were identified from a prospectively maintained database. Patients treated with thrombectomy were either ineligible for IV tPA or refractory to thrombolysis after receiving IV tPA within 4.5 h of stroke onset.3 (link),19 (link) The mechanical clot retrieval devices included Merci Retriever (Stryker neurovascular, Mountain View, CA), Penumbra System (Penumbra, Inc., Alameda, CA), stent retriever with Solitaire FR device (Covidien/eV3, Dublin, Ireland), or Trevo Retriever (Stryker neurovascular).
Magnetic resonance imaging (MRI) before thrombectomy was routinely performed in all patients without selection biases unless contraindicated. Patients also typically underwent follow-up magnetic resonance (MR) within 48 h after thrombectomy. The multimodal MRI protocol included diffusion-weighted imaging, perfusion-weighted imaging, T2∗ gradient-recall echo (GRE), and fluid-attenuated inversion recovery (FLAIR) sequences. We included patients who had serial T2∗ GRE before and 48 h after thrombectomy. The local institutional review board of University of California at Los Angeles approved the study. Informed consent was obtained from the patient or their representative.
Magnetic resonance imaging (MRI) before thrombectomy was routinely performed in all patients without selection biases unless contraindicated. Patients also typically underwent follow-up magnetic resonance (MR) within 48 h after thrombectomy. The multimodal MRI protocol included diffusion-weighted imaging, perfusion-weighted imaging, T2∗ gradient-recall echo (GRE), and fluid-attenuated inversion recovery (FLAIR) sequences. We included patients who had serial T2∗ GRE before and 48 h after thrombectomy. The local institutional review board of University of California at Los Angeles approved the study. Informed consent was obtained from the patient or their representative.