VT Diagnostic Imaging Techniques 5

Question 1

Which imaging technique uses phase-contrast principles to quantify blood flow volume (mL/min) in a vessel?

Accepted Answer

Phase-contrast MRI

Answer

Phase-contrast MRI encodes velocity as phase shifts and can calculate volumetric flow rate by integrating velocity across the vessel cross-section.

Question 2

When evaluating mesenteric arteries post-prandially, the expected change in the superior mesenteric artery (SMA) waveform is:

Accepted Answer

Decreased resistance with increased diastolic flow

Answer

After eating, splanchnic vasodilation lowers mesenteric resistance, producing increased end-diastolic velocity and a low-resistance SMA waveform compared to the fasting state.

Question 3

The term 'isoechoic' in ultrasound describes tissue that:

Accepted Answer

Has similar echogenicity to adjacent tissue

Answer

Isoechoic means the structure returns echoes of similar brightness to the surrounding reference tissue, making it difficult to distinguish from background.

Question 4

A 'string sign' seen on carotid arteriography indicates:

Accepted Answer

Near-total carotid occlusion with a thin residual lumen

Answer

The string sign describes the extremely narrow thread-like residual contrast column seen in near-total internal carotid artery occlusion with a hairline patent lumen.

Question 5

Which duplex parameter is used to calculate the resistive index (RI) in renal artery assessment?

Accepted Answer

(PSV − EDV) / PSV

Answer

RI = (PSV − EDV) / PSV; values above 0.70 in the renal parenchymal arteries suggest elevated intrarenal resistance.

(VT) Vascular Technician Certification Practice Test

(VT) Vascular Technician Certification Practice Test

VT Diagnostic Imaging Techniques 5