Atherosclerosis 197 (2008) 457–464 Relationship between degree of remodeling and CT attenuation of plaque in coronary atherosclerotic lesions: An in-vivo analysis by multi-detector computed tomography Michael Schmid a,∗ , Tobias Pflederer a , Ik-Kyung Jang b , Dieter Ropers a , Komatsu Sei a , Werner G. Daniel a , Stephan Achenbach a a Department of Internal Medicine 2 (Cardiology), University of Erlangen, Erlangen, Germany b Cardiology Division, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA Received 29 December 2006; received in revised form 24 June 2007; accepted 11 July 2007 Available online 29 August 2007 Abstract Multi-detector CT (MDCT) permits non-invasive visualization of the coronary arteries. Coronary plaque can be visualized, and earlier studies have indicated that the CT attenuation measured in atherosclerotic plaques is influenced by plaque composition. Also, MDCT has been shown to permit assessment of remodeling of coronary atherosclerotic lesions. It is assumed that both lipid-rich plaques and those that display positive remodeling are more prone to rupture and erosion. We thus evaluated the relationship between remodeling and CT attenuation of coronary atherosclerotic plaque by MDCT. Methods: Seventy-six patients were investigated by contrast-enhanced 64-slice CT. One-hundred twelve atherosclerotic lesions without substantial calcification and visualized with high image quality were selected. Multiplanar reconstructions orthogonal to the coronary artery were rendered at the lesion and the proximal reference site. Cross-sectional vessel areas were measured to determine the remodeling index (RI: lesion vessel area/reference vessel area) and the CT attenuation of plaque was measured by fitting a region of interest to the plaque area. CT attenuation of plaque was correlated to the presence of positive remodeling index (RI > 1.05). Results: The mean cross-sectional vessel area in the lesion was 0.25 ± 0.08 cm 2 , the mean reference vessel area was 0.22 ± 0.09 cm 2 . The mean CT attenuation of the atherosclerotic plaque in the lesions was 71 ± 26 HU. CT attenuation of plaque was significantly lower in 72 lesions that displayed positive remodeling (59 ± 22 HU) than in 40 lesions with no or with negative remodeling (91 ± 20 HU, p < 0.001). Conclusions: Positive remodeling of coronary atherosclerotic lesions correlates to lower CT attenuation of plaque, which has been demon- strated to be associated with lipid-rich plaque. Both characteristics indicate increased risk for plaque rupture and subsequent events and could thus prove useful when the use of CT imaging for the detection of “vulnerable plaque” is considered. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Multi-detector computed tomography; Coronary atherosclerotic plaque; Remodeling; Plaque attenuation; Coronary arteries; Vulnerable plaque 1. Introduction Cardiovascular disease is the most frequent cause of mor- bidity and mortality in developed countries [1]. The sudden rupture or superficial erosion of a coronary plaque with sub- ∗ Corresponding author at: Medizinische Klinik 2 (Kardiologie), Univer- sit¨ atsklinikum Erlangen, Ulmenweg 18, 91054 Erlangen, Germany. Tel.: +49 9131 8535301; fax: +49 9131 8535303. E-mail address: Schmid1208@gmx.de (M. Schmid). sequent thrombosis is currently acknowledged as the typical mechanism for acute coronary syndromes [2,3]. Thus, the development of non-invasive imaging modalities to assess the burden of atherosclerosis, to detect “vulnerable” plaques, and to potentially monitor the efficacy of both therapeutic and preventive approaches to atherosclerosis is a major focus of research [4,5]. Multi-detector row computed tomography (MDCT) per- mits reliable imaging of the coronary artery lumen and vessel wall after injection of contrast agent in a single breath 0021-9150/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.atherosclerosis.2007.07.003