Is multiparametric ultrasound the future of unstable carotid plaque diagnostics?

Objectives. Evaluate the effectiveness of contrast enhanced ultrasound (CEUS) for detecting carotid
plaque instability and neovascularization in reference to Superb Microvascular Imaging (SMI), and
histological samples.
Materials and Methods. Incidence of stroke every year increases worldwide, According to World
Health Organization In 2020, 1 in 6 deaths from cardiovascular disease was due to stroke, about 87% of all
strokes are ischemic strokes, in which blood flow to the brain is impaired and atherosclerotic disease is one
of the main causes. In these situations, CEUS and SMI is used to detect neovascularization, as a factor of
atherosclerotic plaques instability.
During the prospective research, 88 patients underwent Doppler ultrasound examination, and significant
hemodynamic plaques (> 50%) were detected, following SMI and CEUS. The neovascularization was
categorized in three categories (Grade 0, Grade 1, Grade 2) and results were compared to histological
finding from endarterectomies in 62 patients.
Results. There was a positive correlation between SMI and histological material, r = 0.319; p = 0.01.
Also, positive correlation was found between CEUS and histological material, r = 0.456; p = 0.000.
Moderate positive correlation was observed between CEUS and SMI r = 0.669; p = 0.000. However, ROC
curve analysis showed that SMI is less sensitive than CEUS (51.22% vs 80.56%) Totally CEUS method
is valued with the sensitivity – 80.56%, specificity – 77.75%, accuracy – 79.29% with limitation among
calcified plaques.
Grade 1 atherosclerotic plaques showed delayed neovascularization (mean time 32 seconds) in comparison
to Grade 2 (mean time 19 seconds).
Conclusions. CEUS and SMI as a part of multiparametric ultrasound method shows promising
results for carotid plaque instability evaluation than US doppler or microvascular imaging solely and it
can be advised in clinical practice for patients with carotid artery soft plaques. Grade 2 plaques show
earlier neovascularization than Grade 1 atherosclerotic plaques. However, the sensitivity of CEUS and SMI
decreases in markedly calcified plaques.