Carotid ultrasonography (carotid U/S) is an ultrasound of the carotid arteries. Carotids are the arteries in your neck that supply blood to your brain. A small transducer, similar to the one used for listening with a stethoscope, is placed on the patient’s neck next to their windpipe (trachea). When it’s pressed firmly into place, the transducer emits sound waves that bounce back and create echoes when they hit objects – in this case, different types of tissue in the carotid artery. Carotid ultrasounds are most often done in order to look at plaque build-up inside of blood vessels (“carotid intima-media thickness”), but they can also be done to look for atherosclerotic plaques, blood clots, and narrowing of the carotid arteries. Carotid ultrasounds are usually done on people who have risk factors for or a history of stroke or transient ischemic attack (TIA). Carotids ultrasound images may be interpreted by a sonographer and reported by an ultrasonographer or vascular technologist. Carotids U/S reports will often include measurements such as the thickness of the intima-media complex (IMT), which is used to assess plaque build-up. Carotids ultrasounds also provide information about any stenosis in the carotid artery, which can lead to decreased blood flow. Carotids U/S is also referred to as Carotids duplex U/S. Carotid ultrasounds are sometimes done in conjunction with carotid duplex Doppler ultrasounds, another type of ultrasound that provides information about blood flow in the arteries. Carotids duplex Doppler ultrasounds are most often used to look for carotid artery stenosis or occlusions. Ultrasound is a painless procedure that takes very little time. Carotid percussions can be performed at the bedside by compressing the neck over the artery and producing a thudding sound when it is released. This technique has been replaced by high-frequency ultrasound because it is more sensitive but less specific in detecting vascular abnormalities . Carotid auscultation has been shown to have a specificity of less than 50% for identifying vascular pathology. Carotids ultrasounds may be used to look at the following: Carotids arch – Carotids bifurcation – Carotid body – Carotids endarterectomy – Carotids “halo sign” – Carotid intima-media thickness (IMT) – Carotid lumen stenosis/obstruction – Carotids plaque build-up – Carotid plaques, calcified plaques, and complex composite plaques. Carotid Artery Ultrasound Images. Carotid artery ultrasound image showing noncompliant left carotid wall.