Reader Response: Multimodal CT or MRI for IV Thrombolysis in Ischemic Stroke With Unknown Time of Onset.

Abstract

We read with interest the article published by Macha et al.1 on multimodal CT or MRI for IV thrombolysis in ischemic stroke with unknown time of onset. Although there were randomized controlled trials already published emphasizing the use of intravenous recombinant tissue plasminogen activator (IV rTPA) beyond the approved time frame (>4.5 hours) in acute ischemic stroke,2,3 your study provided another important aspect: time after receiving the patient in the form of door-to-imaging time, imaging-to-needle time, and door-to-needle time. These studies also supported the use of IV rTPA in an unknown or extended time window with the help of multimodal CT or MRI. Although they concluded that CT imaging led to faster door-to-needle time (45 minutes) compared with MRI-based imaging (75 minutes), they stated that it could change over time because of the availability of more advanced and faster MRI facilities.4 MRI also has added advantages: to perform vascular study without the use of contrast and to provide better visualization of brain parenchyma, which helps in the assessment of microbleeds. Treatment time can be further reduced by using tenecteplase, which can be given as a bolus instead of an infusion over the course of an hour.