A systematic review of histology and imaging methods detecting carotid plaque components associated with ischemic stroke

Abstract

Master thesis, Programme in Medicine TITLE: A systematic review of histology and imaging methods detecting carotid plaque components associated with ischemic stroke. Background: Rupture of atherosclerotic plaques in the carotid circulation is one of the major causes of ischemic stroke. The recent risk-stratifier for evaluating stroke risk is based on area of lumen narrowing although recent research indicates that plaque components and morphology might be of greater importance. A lot of research is in progress with the aim to find a cost-effective and non-invasive imaging method that adequatly can detect plaque components associated with an increased risk of creating ischemic events. Objective: The aim of this systematic review was to evaluate the scientific evidence for which imaging method of CT and MRI that best identify carotid plaque components associated with an increased risk of creating ischemic events. Methods: Two literature searches (one for each imaging method) was performed in PubMed and Cochrane Central Register of Controlled Trials (CENTRAL). Inclusion criterias was defined and used to select relevant articles. Data were extracted and presented in tables. The quality of the individual articles was assessed. Statistical analyzes could not be performed. Findings: The literature search resulted in 648 articles about CT and 915 about MRI. 6 articles about CT and 8 articles about MRI was included in the analysis. Direct comparisons between studies were not possible because of incomparable methods and outcome measures. Due to this it was not possible to perform any statistical analyze. Instead, a table highlighting the diversity between the articles was performed for each imaging method. However, the results indicated that MRI is a more researched method with better ability to identify plaque components than CT. Interpretation: There is a significant gap in scientific knowledge on this subject. The researchers will need to agree on inclusion criterias, methods to perform imaging, and the use of outcome measures. A standardized list of recommendations of how to perform research on this subject needs to be established in this field. In combination with larger trials and representative populations, the results could be comparable, analyzes could be performed and conclusions be reliable. Keywords: ”Carotid stenosis”, ”Vulnerable plaque”, ”Ischemic stroke”, ”Computed Tomography”, ”Magnetic Resonance Imaging