Dynamic contrast-enhanced MR imaging of carotid vasa vasorum in relation to coronary and cerebrovascular events

Abstract Background and aims Dynamic contrast-enhanced MR imaging (DCE-MRI) provides a noninvasive approach to the functional status of carotid adventitial vasa vasorum . Contrast extravasation rate, or K trans , derived from kinetic modeling of adventitial enhancement, has been correlated with plaque neovascularization and inflammation. This study sought to clarify the clinical implications of K trans by evaluating its relationship with documented cardiovascular events (CVE). Methods Seventy patients with carotid plaque at clinical ultrasound examination were recruited and imaged with a previously-described bright-blood DCE-MRI protocol (spatial resolution: 0.55 × 0.58 mm2 ; time resolution: 18 s). Patients were classified by the presence of documented coronary and/or cerebrovascular events. Adventitial K trans was estimated via kinetic modeling of outer wall enhancement as captured by DCE-MRI. Results After excluding six patients with insufficient image quality, 64 patients (66 ± 12 years, 51 male) had DCE-MRI measurements. Patients with documented CVE showed significantly higher adventitial K trans than those without (0.056 ± 0.024 versus 0.034 ± 0.008 min−1 , p 0.05): 0.054 ± 0.027 min−1 in patients with coronary events alone, 0.056 ± 0.018 min−1 in patients with cerebrovascular events alone, and 0.069 ± 0.022 min−1 in patients with both. Carotid adventitial K trans was negatively correlated with time since clinical event (Spearman's rho = −0.40, p = 0.003). Conclusions Patients with documented CVE demonstrated increased rate of contrast extravasation from carotid adventitial vasa vasorum on DCE-MRI irrespective of the territory of events. Systemic factors implicated in the pathophysiology of acute atherothrombotic events may influence the functional status of adventitial vasa vasorum.