Hubertus Fritz Georg Mueller
University Hospital of Geneva and Medical School, Switzerland
Hubertus Fritz Georg Mueller is a consultant in stroke medicine and neurology at the University Hospital of Geneva. He holds the Swiss certification and French Diploma in cerebrovascular diseases and obtained a research grand by the Swiss National Foundation for work on cervical arterial dissections and arteriosclerosis. Recent research includes inflammatory biomarkers in carotid artery disease, PET imaging and contrast enhanced ultrasound of the carotid plaque.
Background and purpose: The aim of our study was to evaluate whether neovascularization of the carotid plaque may be accurately assessed by visual analysis of contrast enhanced ultrasound imaging (CEUI) and whether these findings correlate with software intensity over time curve analysis (ITC) and histopathology. We further investigated in a follow up study correlation of visual analysis to hyperintensity signals in MRI black blood sequences. Patients and methods: Patients with >50% ECST symptomatic or >60% asymptomatic stenosis were included. 4 investigators evaluated contrast enhancement visually (3 grades) with positive agreement when ≥3 investigators were unanimous. ITC analysis of contrast enhancement was performed in the plaque and in the lumen. Histopathology (microvessel density with CD34+ staining) was completed whenever endarterectomy was performed. MRI included black blood sequences of the carotid artery and intraplaque hemorrhage was determined by presence of a hyperintensity signal within the carotid plaque. Results: Visual grading (33 patients, interobserver agreement 94%) correlated significantly with ITC analysis: (p=0.03). Histopathology (N=19) revealed a larger CD34+ area in patients with grade 1/2 vs. grade 0 (p=0.03). Additionally, thirteen carotid plaques from 12 patients were analysed by means of CEUI and MRI. Intraplaque hemorrhage detected by MRI (n=10) showed a significantly higher neovascularization analyzed by CEUI (median grade 1 vs. 0, p=0.03). Conclusion: Visual analysis of neovascularization by means of CEUI is accurate and reproducible with a significant correlation with ITC, histopathology and a hyperintensity signal on MRI black blood sequences.