[Diagnostic imaging of carotid stenosis: ultrasound, magnetic resonance imaging, and computed tomography angiography].

Carotid artery stenosis is increasingly a cause of stroke in Japan. Diagnostic imaging techniques are available, including ultrasound, 3D computed tomography angiography (CTA), magnetic resonance imaging (MRI), and cerebral angiography (DSA). The stenosis ratio measuring vessel diameter is a major criteria for surgical indications. CTA and DSA are definitive diagnostic procedures. Plaque imaging reveals a lipid-rich core, intraplaque hemorrhage, and thin fibrous cap. Atheromatic plaque with these components of vulnerable plaque is also a risk factor for stroke in addition to the stenosis ratio. As screening methods, ultrasound and magnetic resonance angiography are useful. Ultrasound and MRI provide valuable information on plaque imaging. Angiography remains essential for carotid stenting. For screening study prior to surgical or endovascular treatment and follow-up, the appropriate imaging modality should be selected for each patient with carotid stenosis to prevent stroke.