Utility of Complementary Magnetic Resonance Plaque Imaging and Contrast‐Enhanced Ultrasound to Detect Carotid Vulnerable Plaques

Figure 1. A and B, Magnetization‐prepared rapid acquisition with gradient echo (MPRAGE) and contrast‐enhanced ultrasound (CEUS) findings of plaques. C, Intraplaque hemorrhage (IPH) score and neovessel density for each group (groups A–D in B). HIP indicates high–signal‐intensity plaque.

Figure 2. A, Box plot shows the intraplaque hemorrhage (IPH) score of plaques in high–signal‐intensity plaque (HIP) and non‐HIP groups. B, Box plots show the neovessel density of plaques in the high‐ and low‐contrast effect groups of contrast‐enhanced ultrasound (CEUS). The top border of the box shows the 75th percentile, the whisker shows the range of the data, and the horizontal line in the box shows the median. MPRAGE indicates magnetization‐prepared rapid acquisition with gradient echo.

Figure 3. The receiver operating characteristic curve for detecting symptomatic plaques showed that the combined use of magnetization‐prepared rapid acquisition with gradient echo (MPRAGE) and contrast‐enhanced ultrasound (CEUS) was significantly more effective (area under the curve [AUC], 0.79; P<0.0001) than MPRAGE alone (AUC, 0.58; P=0.07) (P=0.0008).

Figure 4. A case of amaurosis fugax refractory to medical treatment with symptomatic non–high–signal‐intensity plaque (HIP) on magnetization‐prepared rapid acquisition with gradient echo (MPRAGE) with a high‐contrast effect on contrast‐enhanced ultrasound (CEUS). A and B, Magnetic resonance angiography (A) and long‐axis color Doppler ultrasound (B) images show a severely stenotic plaque in the internal carotid artery (ICA). A, MPRAGE images (axial) show non‐HIP. C, With CEUS (shown as the square in B), many microbubbles are recognized in the plaque (red arrowheads), which is classified as grade 3. D, Photomicrograph of a carotid endarterectomy specimen with a large necrotic core (high magnification of the square) shows extensive neovascularization (black arrows) and a small amount of intraplaque hemorrhage (black arrowheads). ECA indicates external carotid artery.