A meta analysis and hierarchical classification of HU-based atherosclerotic plaque characterization criteria

• Published in: PloS one Vol. 8; no. 9; p. e73460
• Main Authors: Kristanto, Wisnumurti, van Ooijen, Peter M A, Jansen-van der Weide, Marijke C, Vliegenthart, Rozemarijn, Oudkerk, Matthijs
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.09.2013; Public Library of Science (PLoS)
• Subjects: Angina pectoris; Arteriosclerosis; Atherosclerosis; Attenuation; Calcification; Cardiovascular disease; Carotid arteries; Classification; Collimation; Computed tomography; Coronary vessels; Correlation analysis; Criteria; Documents; Heart; Humans; Lipids; Medical imaging; Meta-analysis; Models, Theoretical; Pathology; Plaque, Atherosclerotic - classification; Plaques; Sensors; Studies; Tomography; Netherlands
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0073460

Many computed tomography (CT) studies have reported that lipid-rich, presumably rupture-prone atherosclerotic plaques can be characterized according to their Hounsfield Unit (HU) value. However, the published HU-based characterization criteria vary considerably. The present study aims to systematically analyze these values and empirically derive a hierarchical classification of the HU-based criteria which can be referred in clinical situation. A systematic search in PubMed and Embase for publications with HU-criteria to characterize lipid-rich and fibrous atherosclerotic plaques resulted in 36 publications, published between 1998 and 2011. The HU-criteria were systematically analyzed based on the characteristics of the reporting study. Significant differences between HU-criteria were checked using Student's t-test. Subsequently, a hierarchical classification of HU-criteria was developed based on the respective study characteristics. No correlation was found between HU-criteria and the reported lumen contrast-enhancement. Significant differences were found for HU-criteria when pooled according to the respective study characteristics: examination type, vessel type, CT-vendor, detector-rows, voltage-setting, and collimation-width. The hierarchical classification resulted in 21 and 22 CT attenuation value categories, for lipid-rich and fibrous plaque, respectively. More than 50% of the hierarchically classified HU-criteria were significantly different. In conclusion, variations in the reported CT attenuation values for lipid-rich and fibrous plaque are so large that generalized values are unreliable for clinical use. The proposed hierarchical classification can be used to determine reference CT attenuation values of lipid-rich and fibrous plaques for the local setting.