CCI Cerebrovascular Duplex Examinations 5

Question 1

During TCD monitoring for microembolic signals (MES), an embolic signal is characterized by which property?

Accepted Answer

Unidirectional, high-intensity, transient signal lasting <300 ms within the Doppler spectrum

Answer

MES are unidirectional, high-intensity transient signals <300 ms duration occurring randomly within the cardiac cycle, distinct from artifacts.

Question 2

Which clinical scenario would MOST warrant a cerebrovascular duplex examination as the initial imaging study?

Accepted Answer

Transient ischemic attack with hemispheric symptoms

Answer

Carotid duplex is the first-line investigation for hemispheric TIA to identify treatable carotid stenosis as a potential embolic source.

Question 3

What is the clinical significance of identifying a carotid 'string sign' on duplex ultrasound?

Accepted Answer

It indicates near-total occlusion with a thin trickle of residual flow

Answer

The string sign describes a thread-like trickle of flow through a near-total ICA occlusion, an important distinction from complete occlusion since it may still be treatable.

Question 4

Fibromuscular dysplasia (FMD) of the internal carotid artery most commonly involves which segment and appears as what pattern on duplex?

Accepted Answer

Mid-to-distal ICA; alternating stenoses and dilations producing a 'string of beads' appearance

Answer

FMD characteristically affects the mid-to-distal cervical ICA, producing the classic angiographic and ultrasound 'string of beads' pattern of alternating stenoses and aneurysmal segments.

Question 5

During carotid duplex, spectral broadening is defined as filling in of which portion of the Doppler waveform?

Accepted Answer

The temporal window beneath the systolic peak (systolic window)

Answer

Normal laminar flow produces a clear systolic window (spectral window) under the waveform envelope; spectral broadening fills this window, indicating turbulent or disturbed flow.

CCI - Cardiovascular Credentialing International Practice Test

CCI - Cardiovascular Credentialing International Practice Test

CCI Cerebrovascular Duplex Examinations 5