CCI - Cardiovascular Credentialing International Cerebrovascular Duplex Examinations Questions and Answers

Question 1

A sonographer performs a carotid duplex exam and obtains the following measurements in the left internal carotid artery (ICA): Peak Systolic Velocity (PSV) = 255 cm/s, End-Diastolic Velocity (EDV) = 110 cm/s, and an ICA/CCA PSV ratio of 4.5. Based on the Society of Radiologists in Ultrasound (SRU) consensus criteria, what is the estimated degree of stenosis?

Accepted Answer

≥70% stenosis to near occlusion

Answer

According to the widely accepted SRU consensus criteria, an ICA Peak Systolic Velocity (PSV) greater than 230 cm/s is a primary indicator for a stenosis of ≥70%. [17, 26] The additional findings of an End-Diastolic Velocity (EDV) >100 cm/s and an ICA/CCA PSV ratio >4.0 further support this conclusion, placing the stenosis in the ≥70% to near occlusion category. [17]

Question 2

Which of the following findings is most definitive for identifying the External Carotid Artery (ECA) as distinct from the Internal Carotid Artery (ICA)?

Accepted Answer

Visualization of cervical branches

Answer

While the ECA typically has a higher resistance waveform, is often smaller, and is usually located anteromedial to the ICA, these characteristics can be variable. The most definitive and unambiguous sonographic finding to identify the ECA is the visualization of its branches, such as the superior thyroid, ascending pharyngeal, or facial arteries, originating from it in the neck. [1, 3, 7]

Question 3

A duplex ultrasound of the vertebral arteries reveals sustained retrograde (reversed) flow in the left vertebral artery. This finding is a classic sign of which condition?

Accepted Answer

Occlusion or high-grade stenosis of the proximal left subclavian artery

Answer

Sustained retrograde flow in a vertebral artery is the hallmark of subclavian steal syndrome. This occurs when there is a severe stenosis or occlusion in the subclavian artery proximal to the origin of the vertebral artery. [9, 20] The pressure drop in the arm causes blood to flow down the vertebral artery (in a reverse direction) to supply the ischemic arm, 'stealing' it from the cerebral circulation. [9, 24]

Question 4

During a carotid evaluation, the sonographer observes a low-velocity, delayed systolic upstroke, and rounded systolic peak in the left Common Carotid Artery (CCA). This waveform morphology, known as 'tardus parvus,' suggests a significant stenosis in which location?

Accepted Answer

Left Subclavian or Brachiocephalic Artery

Answer

A 'tardus parvus' waveform indicates the dampening effect of a significant stenosis or occlusion proximal (upstream) to the point of sampling. [14, 19] Since the waveform is observed in the left CCA, the flow obstruction must be located more proximally, such as in the left subclavian artery or the brachiocephalic (innominate) artery, which gives rise to the right-sided vessels. [8, 16]

Question 5

A sonographer identifies atherosclerotic plaque in the carotid bifurcation that appears brightly echogenic and produces a strong posterior acoustic shadow, obscuring the vessel wall behind it. How is this type of plaque best characterized?

Accepted Answer

Ulcerated

Answer

Markedly hyperechoic (bright) plaque that causes posterior acoustic shadowing is characteristic of calcified plaque. [6, 12] The dense calcium deposits do not allow the ultrasound beam to pass through, creating a shadow behind the plaque. Soft plaques are typically hypoechoic, and homogeneous plaques have a uniform texture without significant shadowing. [6]

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Cerebrovascular Duplex Examinations Questions and Answers