An international, Phase III clinical trial studying ultrasound in combination with tPA - the only current therapy for stroke caused by a blood clot in an artery - to treat acute ischemic stroke has begun at The University of Texas Health Science Center at Houston (UTHealth). The trial will recruit 830 patients in approximately 60 sites around the world. The UTHealth Medical School site was the first in the world to enroll a patient, Enrique Chapa, 75, of Houston.