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Abstract
High-resolution carotid MRI allows visualization of carotid atherosclerotic plaque characteristics. MRI serves as a noninvasive option for the detection of active plaque inflammation and intraplaque hemorrhage. Significant gains in signal-to-noise ratio and contrast-to-noise ratio can be obtained for carotid atheroma imaging at 3T compared with 1.5T. Normalized wall index or wall area on MRI has shown its efficacy in monitoring the response after medical therapy. T(2)* quantification in carotid plaques before and after the administration of ultrasmall superparamagnetic iron oxide particles shows difference in response to treatment according to drug doses. In conclusion, high-resolution MRI is useful in the diagnosis and monitoring of carotid atherosclerotic plaques prone to transient ischemic attack and stroke.
Figures and Tables
Fig. 1
Lipid-rich plaque. T1-weighted image (a) shows slightly increased signal intensity in the plaque (arrow). T2-weighted image shows a portion of bright signal intensity (arrowheads in the plaque which suggests the presence of fibrosis. The darker signal intensity in the plaque (arrow) implicates lipid-rich components.
Fig. 2
Hemorrhagic plaque in a 64-year-old male with vascular dementia. The plaque signal intensity is bright on a T1-weighted image (a), T1-weighted image with fat-saturation (b), and source image of time-of-flight MR angiography (c). On a maximum intensity projection image (d), there is a halo sign (arrow) due to intraplaque hemorrhage.
Fig. 3
Necrotic plaque in a 73-year-old male with stroke.
a. A source image of time-of-flight MR angiography shows severe luminal narrowing (arrow) of the left internal carotid artery.
b. contrast-enhanced T1-weighted MR image shows no significant enhancement in the plaque except the outer layers.
Fig. 4
Plaque regression after statin treatment in a 73-year-old male.
a. T1-weighted image with fat-saturation at 1.5T shows an eccentric plaque in the left internal carotid artery.
b. T1-weighted image with fat-saturation at 3T shows significant improvement in plaque thickness after 3-year low dose statin treatment.
References
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