Indications for mechanical thrombectomy and the role of CT perfusion

Final ID:

287 

Type:

Educational Exhibit-Poster Only  

Authors:

R Dougherty1, M Manganaro1, J Griauzde1

Institutions:

1Michigan Medicine, Ann Arbor, MI

First Author:

Ryne Dougherty, MD MBA  
Michigan Medicine
Ann Arbor, MI

Co-Author(s):

Matthew Manganaro  
Michigan Medicine
Ann Arbor, MI
Julius Griauzde  
Michigan Medicine
Ann Arbor, MI

Presenting Author:

Ryne Dougherty, MD MBA  
Michigan Medicine
Ann Arbor, MI

Learning Objectives:

Review recent mechanical thombectomy trials
Explain the pathophysiologic basis for CT perfusion
Demonstrate an approach to reading CT perfusion cases

Background:

In 2015, four landmark trials were published which re-defined the treatment algorithm of acute ischemic stroke. Following the publication of the MR CLEAN, ESCAPE, EXTEND-IA and SWIFT PRIME trials, mechanical thrombectomy with or without IV tpa became the gold standard treatment in the first 6 hours following symptom onset.[1-4] More recently, the eligibility time-frame for mechanical thrombectomy was extended with the publication of the DAWN and DEFUSE-3 trials. [5, 6] These trials lengthened the time interval for with CT and MR perfusion playing a central role in patient selection Perfusion imaging in these trials aimed to identify the ischemic core (non- salvageable tissue) and the penumbra (tissue at risk).[7]

Clinical Findings/Procedure Details:

CT perfusion (CTP) is an effective diagnostic tool to evaluate acute ischemic stroke.[7, 8] It has been shown to increase the diagnostic certainty for both expert and non-expert readers. [7] CTP aims to quantify cerebral blood flow (CBF) and cerebral blood volume (CBV), the volume of blood within an imaging voxel. These parameters are used to calculate the mean transit time (MTT) which is the average transit time of the contrast bolus through the specific volume of brain. Areas of matched perfusion abnormalities on CBV and MTT represent the ischemic core while areas of mismatched perfusion abnormalities on CBV and MTT represent the penumbra.[7] The differences in imaging parameters is review in table one.

Conclusion and/or Teaching Points:

Identify mechanical thrombectomy trials and CT perfusion's role
Describe the pathophysiology of CTP in ischemic stroke to approach CT perfusion
Review patient cases where CTP aided treatment

Abstract Categories:

Education and Training

Keywords:

CT perfusion
Neurointervention
Thrombectomy