Imaging Carotid Atherosclerosis Plaque Ulceration: Comparison of Advanced Imaging Modalities and Recent Developments

Abstract

Atherosclerosis remains the leading cause of long-term mortality and morbidity worldwide, despite remarkable advancement in its management. Vulnerable atherosclerotic plaques are principally responsible for thromboembolic events in various arterial territories such as carotid, coronary, and lower limb vessels. Carotid plaque ulceration is one of the key features associated with plaque vulnerability and is considered a notable indicator of previous plaque rupture and possible future cerebrovascular events. Multiple imaging modalities have been used to assess the degree of carotid plaque ulceration for diagnostic and research purposes. Early diagnosis and management of carotid artery disease could prevent further cerebrovascular events. In this review, we highlight the merits and limitations of various imaging techniques for identifying plaque ulceration.

Fig 1.

Histologic section of an ulcerated plaque by using a hematoxylin-eosin stain showing the ulceration (left). The CD68 stain shows macrophages (middle), and the smooth-muscle actin stain shows a lack of smooth-muscle cells (right). Reprinted with permission from Gillard et al. Copyright Cambridge University Press 2007.

Fig 2.

DSA image of 2 large ulcerations (arrows) of a right internal carotid artery. Reprinted with permission from Gillard et al. Copyright Cambridge University Press 2007.

Fig 3.

A, Doppler sonography shows an internal carotid artery plaque ulceration (white arrow) The asterisk shows weakly echogenic plaque material, presumably lipid. Reprinted with permission from Gillard et al. Copyright Cambridge University Press 2007. B, The calcification in the anterior vessel wall (white arrow) shadows the color Doppler signal and opposite wall structures (yellow arrow). JV indicates jugular vein; CCA, common carotid artery. Adapted from Steinke et al.

Fig 4.

A, 2D sonography depicts a smooth plaque, arrow shows the stenosis. B, 3D sonography shows an ulceration of the same plaque in another plane, arrow shows an ulcer at site of shear stress. The figure is adapted with permission from Heliopoulos et al.

Fig 5.

A, An ulceration (yellow arrow) in a heavily calcified (white arrows) plaque. B, The ulcer is clearer with the calcification removed by dual-energy CTA.

Fig 6.

Luminal irregularity in the internal carotid artery is demonstrated on both a nonenhanced hybrid of pseudocontinuous and pulsed arterial spin-labeling (arrow, A) and CE-MRA (C) images, but it is not seen on the 3D TOF image (dashed arrow, B). hASL indicates hybrid of pseudocontinuous and pulsed ASL. The figure is reproduced with permission from Koktzoglou et al.

Fig 7.

High-resolution MR imaging, CTA, and sonography of the left carotid artery of a 77-year-old man. Ulcerations (yellow arrow) are shown clearly on CE-MRA (A) and pre- and postcontrast black-blood T1-weighted (D and E) images; however, they were missed on TOF-MRA (B). The calcification on CTA (white arrow, C) causes difficulty when observing the ulceration. Doppler sonography (F) shows no ulceration in the internal carotid artery.