US Eval of Extracranial arteries

ICA US characteristics

No extracranial branches seen

Larger caliber

Courses posterior and lateral

Low resistance flow

No temporal tap

ECA US characteristics

Extracranial branches seen

Smaller caliber

Courses anterior and medial

High resistance flow

Temporal tap response

Intimal medial thickness

Predictor of cardiovascular events

Best measurement is when US beam is perpendicular to the vessel wall

Distal CCA measurements are most common

NORMAL VALUE: 0.4-1mm (increase with age)

Decreased cardiac function =

Decreased flow

Normal CCA velocity

PSV <125cm/s and EDV <40cm/s

ECA flow velocity

PSV <150cm/s

ICA velocity

PSV <125cm/s and EDV <40cm/s

Vertebral artery flow

Antegrade flow moving toward the brain

Monophasic with mild diastolic flow

Velocities should be similar between left and right

What is the first step in a carotid ultrasound?

Perform bilateral brachial pressures

What measurements can be obtained from the transverse views of the carotid arteries?

Area stenosis

Only the proximal segment of the ______ is evaluated during a carotid ultrasound

ECA

The Doppler cursor angle should be set so it is parallel to the:

The moving blood flow

Measurement of CCA IMT measurements are best performed with the US beam ____________, while Doppler velocities are best obtained with the ultrasound beam __________

Perpendicular to the vessel wall; Parallel to the blood flow

Which of the following vessels demonstrates the highest resistance in a normal patient?

ICA

CCA

ECA

Vert

ECA

Which of the following describes how to locate the vertebral arteries?

Sweep posterior from a longitudinal view of the CCA