 DESIGN: NOR-SASS is a PROBE prospective randomised, open-label, blinded endpoint trial, designed to establish the superiority of contrast-enhanced ultrasound treatment given within 412 hours after stroke onset in consecutively admitted patients with acute ischaemic stroke, as compared with 1 standard iv thrombolysis with tenecteplase TNK or alteplase tPA in patients eligible for thrombolytic treatment, and 2 no specific treatment in patients not eligible for thrombolytic treatment. 