Fluoroscopy and Interventional Radiography Flashcards

In percutaneous transluminal angioplasty (PTA), what is the mechanism by which the balloon catheter restores blood flow?

Answer: It is inflated within a stenotic vessel segment to mechanically dilate the narrowing and restore luminal diameter

PTA uses high-pressure balloon inflation to compress atherosclerotic plaque against the vessel wall and plastically deform the artery, increasing luminal diameter without surgical incision.

In digital subtraction angiography (DSA), what is a 'mask' image and how is it used?

Answer: A pre-contrast baseline image electronically subtracted from contrast-filled frames, leaving only opacified vessels visible

The mask is a pre-contrast image acquired immediately before contrast injection; it is logarithmically subtracted from each subsequent contrast frame so that bones and soft tissues cancel out, leaving only the contrast-filled vascular structures.

What are the key steps of the Seldinger technique for vascular access in interventional radiology?

Answer: Needle puncture of vessel, guidewire insertion through needle, needle removal, catheter advancement over guidewire

The Seldinger technique uses a guidewire as an intermediary: the vessel is punctured with a needle, a flexible guidewire is inserted through the needle lumen, the needle is withdrawn, and a catheter is then threaded over the guidewire into the vessel.

Which combination of radiation protection measures is most important for the interventional radiologist who must stand near the patient during fluoroscopic-guided procedures?

Answer: Wearing a full lead apron, thyroid collar, and leaded glasses, and maximizing distance from the beam when possible

Because interventionalists work in close proximity to the scatter source, comprehensive personal shielding (lead apron ≥0.5 mm Pb, thyroid collar, leaded glasses) combined with distance maximization are the primary occupational dose control measures.

In percutaneous nephrostomy, which anatomical approach and calyceal target are preferred to minimize vascular injury?

Answer: Posterior flank approach targeting a posterior calyx, typically in the lower pole

The posterior flank approach targets a posterior calyx (usually lower pole) because posterior calyces lie in the avascular plane of Brödel between the anterior and posterior segmental arteries, minimizing risk of hemorrhage.

What is the primary function of an endovascular stent placed after balloon angioplasty?

Answer: To provide a permanent structural scaffold that maintains vessel patency and prevents elastic recoil or restenosis

A stent is a metallic (or polymer) scaffold deployed within the vessel to oppose elastic recoil, tack up dissection flaps, and maintain the increased luminal diameter achieved by angioplasty.

During an interventional procedure a patient develops urticaria and bronchospasm following contrast injection. What is the correct immediate management priority?

Answer: Administer epinephrine (adrenaline) immediately, call for emergency assistance, and provide airway and circulatory support

Bronchospasm combined with urticaria indicates a severe (anaphylactoid/anaphylactic) contrast reaction requiring immediate intramuscular or IV epinephrine as the first-line drug, along with emergency team activation and supportive airway management.