Imaging of the ulcerated carotid atherosclerotic plaque: a review of the literature

Carotid atherosclerotic disease constitutes a major modern health problem whose diagnosis primarily relies on imaging. Grading of stenosis has been long used as the main factor for risk stratification and guiding of management. Nevertheless, increasing evidence has shown that additional plaque characteristics such as plaque composition and surface morphology play an important role in the occurrence of symptoms, justifying the term "vulnerable plaque". Carotid plaque surface characteristics either in the form of surface irregularities or ulceration represent an important factor of vulnerability and are associated with the occurrence of neurologic symptoms. The delineation of the carotid plaque surface can be performed with virtually all imaging modalities including ultrasound, contrast-enhanced ultrasound, multi-detector computed tomography angiography, magnetic resonance angiography and the traditional reference method of angiography. These techniques have shown varying levels of diagnostic accuracy for the identification of ulcerated carotid plaques or plaque surface irregularities. As a consequence and given its high clinical significance, radiologists should be familiar with the various aspects of this entity, including its definition, classification, imaging findings on different imaging modalities and associations. The purpose of this review is to present the current literature regarding carotid plaque ulcerations and present illustrative images of ulcerated carotid plaques. TEACHING POINTS • Plaque surface and ulceration represent risk factors for stroke in carotid disease. • Characterisation of the plaque surface and ulcerations can be performed with every modality. • US is the first-line modality for carotid disease and identification of ulcerations. • The administration of microbubbles increases US accuracy for diagnosis of carotid ulceration. • MDCTA and MRA are valuable for diagnosing ulceration and evaluating plaque composition.