Detection of Carotid Adventitial Vasa Vasorum and Plaque Vascularization With Ultrasound Cadence Contrast Pulse Sequencing Technique and Echo-Contrast Agent

Abstract

Background and Purpose-Adventitial vasa vasorum and plaque vascularization have been established as predictors of unstable atheromasic lesions in cerebro-and cardiovascular patients. Ultrasound contrast agents provide reliable information on tissue perfusion and microcirculation. We used contrast ultrasound duplex scanning to identify carotid plaque vascularization. Methods-Contrast carotid duplex scanning was performed in 23 patients with plaques of different degree of stenosis and echogenicity. Results-Plaque vascularization was detected in the fibrous and fibro-fatty tissue and not observed in the calcific nor in the necrotic and hemorrhagic tissue. Constantly, a small vessel was observed under ulcerations. Conclusions-Carotid contrast ultrasound imaging appears to be an emerging technique for identifying plaque angiogenesis. Further studies are needed to clarify the role of plaque angiogenesis for assessing cerebrovascular risk and to monitor effects of therapies aimed to plaque remodelling.

Imaging of the Carotid Artery Vulnerable Plaque

“…Contrast-Enhanced Ultrasound CEUS represents a simple and noninvasive technique for the evaluation of plaque vascularization, allowing for the detection of plaque vasa vasorum that are abundant in vulnerable plaques [86][87][88].…”

Contrast Enhanced Ultrasonography and Carotid Plaque Imaging: from the Hemodynamic Evaluation to the Detection of Neoangiogenesis - The New Approach to the Identification of the Unstable Plaque: from Morphology to Patophysiology

“…They also observed the neovascularization regression after 8 months of statins therapy in a plaque of a diabetic patient. In a recent paper from our group (Vicenzini, 2007), we also observed that plaque vascularization can be easily detected with contrast ultrasound imaging in the the fibrous and fibro-fatty tissue and not observed in the calcific nor in the necrotic and haemorrhagic areas, as expression of plaque remodeling. More evidences are now confirming the reliability of this technique (Shah, 2007;Huang, 2008Coll 2010).…”

“…Echogenicity was also quantified with Gray Scale Median (GSM) computerized analysis (Biasi, 1999) (ECST, 1995), as percentage of the difference between the original and the residual lumen at the maximum site of stenosis and to the relative increase of blood flow velocities (Sabeti, 2004). Contrast ultrasound investigation was performed, as already described (Vicenzini, 2007), after small repeated bolus injections of SonoVue (Bracco Altana Pharma, Konstanz, Germany) in an antecubital vein (20 Gauge Venflon), followed by saline flushes. After identifying the plaque on longitudinal and transverse scans, and after having obtained the baseline B-mode, Color and Power images of the plaque, the 15 Mhz linear array probe with a mechanical index varying from 0.4 to 1.4 with CPS continuous real-time recording software was used to achieve the best visualization of plaque morphology and vascularization, in the same longitudinal view.…”

Stratifying risk: asymptomatic carotid disease

“…The latter is of great interest in vascular practice due to wide availability, short learning curve and anatomic access due to relative superficial location of carotid artery. Vicenzini et al, studying 23 patients with ACAD, demonstrated that neovascularization is constantly present underneath ulcerated areas rendering the plaque potentially more vulnerable 55 . In addition, the angiogenesis network was identified coming from the adventitia towards the inner layers of the plaque, but this pattern was not detected in hyperechoic plaques with acoustic shadow (calcified) nor in those with advance inflammatory changes, such as hypoechoic necrotic plaques 55 .…”

“…Vicenzini et al, studying 23 patients with ACAD, demonstrated that neovascularization is constantly present underneath ulcerated areas rendering the plaque potentially more vulnerable 55 . In addition, the angiogenesis network was identified coming from the adventitia towards the inner layers of the plaque, but this pattern was not detected in hyperechoic plaques with acoustic shadow (calcified) nor in those with advance inflammatory changes, such as hypoechoic necrotic plaques 55 . Regression of the adventitial vasa vasorum in a patient upon initiation of treatment with statins was reported suggesting a potential role for treatment monitoring 56 .…”