Neovasculature arising from the vasa vasorum plays a significant role in atherosclerotic plaque progression and destabilization (1). Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) together with pharmacokinetic modeling has been validated with histology to have the ability to characterize neovascularization and adventitial vasa vasorum in atherosclerotic plaque by using the transfer constant (K^trans) (2, 3). However, the relationship between the DCE-MRI quantified adventitial vasa vasorum of carotid atherosclerotic lesions and cardiovascular events (CVE) remains unclear. Therefore, we sought to investigate the relationship between CVE and neovasculature characteristics in human carotid atherosclerosis quantified by DCE-MRI in this retrospective study.Population: After institutional ethics approval and informed consent were obtained, seventy patients (age: 66±12 years, 54male) with documented carotid plaque (intima-media thickness≥2 mm) at ultrasound examination were recruited. Enrolled subjects had their demographics and cardiovascular risk factors collected, including body mass index (BMI), smoking, hypertension, diabetes, hypercholesterolemia. Prior CVE were collected for each subjects, including coronary artery event (CAE) and cerebral ischemic event (CIE). CAE was defined as myocardial infarction or unstable angina pectoris with signs of myocardial ischemia. CIE was defined as ischemic stroke or TIA. Image acquisition and analysis: All subjects were scanned on a 3.0T scanner (GE Medical Systems) with a custom designed 4-channel carotid coil (University of Washington). Axial DCE images were acquired by a multi-slice 2D SGRE sequence (3) centered at carotid bifurcation with parameters: TR/TE=100/6.2ms, FA=30°, FOV=140×112mm2, matrix=256×192, slice thickness=2 mm, number of slices=6, time interval=18s. Coincident with the third phase, 0.1 mmol/kg of gadodiamide (Magnevist; Bayer Healthcare) was injected at a rate of 2 ml/s by a power injector. After bolus arrival, 10 phases were obtained. Other than DCE-MRI, a standard 2D multi-contrast MR imaging protocol was also used to obtain the morphological (maximum vessel wall thickness) and compositional features (lipid rich/necrotic core (LRNC), calcification (CA), and intraplaque hemorrhage (IPH)) of the carotid plaque (4). Blind review was performed using a custom-designed software (CASCADE, University of Washington) (5). A histology-validated post-processing and pharmacokinetic modeling approach was used to obtain the adventitial transfer constant (K^trans) from the vasa vasorum image (Fig 1) derived from DCE-MRI time series (2,3) for each subject. Statistical analysis: Variables were presented as mean±SD or n(%), and compared using Student t-test or chi-square test as appropriate. Univariate and multivariate logistic regression were performed to identify risk factors for CVE. The odds ratio (OR) and the 95% confidence interval (CI) were reported for each factor. Of 70 patients, 6 (8.6%) were excluded because of poor image quality. Of the remaining 64 patients (age: 66±12 years, 51 male), 12 (19%) had no CVE and 52 (81%) suffered from CVE, including 32(50%) with CAE alone, 15(23%) with CIE alone, and 5 (8%) with both CAE and CIE. The characteristics of CVE group and non-CVE group were summarized in Table 1. Among all features, patients with CVE had higher carotid adventitial K^trans (0.056±0.024 min^-1) compared with subjects without CVE (0.034±0.008 min^-1) (p<0.001). The univariate and multivariate logistic regression analysis further confirm that adventitial K^trans of carotid artery was significantly and independently associated with CVE (OR: 2.8 per 0.01 min^-1 increase; 95%CI: 1.3-6.2; p=0.008), as well as smoking (OR: 8.4; 95%CI: 1.1-65; p=0.042) (Table 2). When analyzing the subgroups of CIE alone, CAE alone and CAE&CIE, the carotid adventitial K^trans in patients with both CAE and CIE (0.069±0.022 min^-1), CIE (0.056±0.018min^-1), and established CAE (0.054±0.027min^-1) were all significantly higher than patients without CVE (0.034±0.008 min^-1) (p<0.001, respectively) (Fig 2).In this study, we found that the adventitial K^trans of carotid artery measured by DCE-MRI was associated with cardiovascular events, including cerebral ischemic event and coronary artery event, suggesting that the neovasculature characteristics in carotid artery is not merely a local vascular risk factor but also a promising systemic marker for cardiovascular risk in other vascular beds. DCE-MRI may be valuable for identifying high risk patients in clinical practice.