ARRT Cardiac-Interventional Radiography key terms

A wide venous channel on the posterior surface of the heart that collects blood from the cardiac veins and drains it into the right atrium near the inferior vena cava. It is a landmark for catheter and pacing lead placement.

A major branch of the left main coronary artery that travels in the anterior interventricular groove and supplies the anterior left ventricle and much of the interventricular septum; proximal occlusion threatens a large area of myocardium.

Branch of the left main coronary artery that courses in the left atrioventricular groove and supplies the lateral and sometimes posterior walls of the left ventricle.

Coronary artery arising from the right sinus of Valsalva and running in the right atrioventricular groove; it supplies the right ventricle and inferior wall and usually gives rise to the artery feeding the sinoatrial node.

The heart's primary pacemaker, a small cluster of specialized cells at the junction of the superior vena cava and right atrium that normally generates impulses 60 to 100 times per minute.

A group of specialized conducting cells in the lower interatrial septum that receives impulses from the atria and delays them briefly before they travel to the bundle of His and the ventricles.

The percentage of blood in the left ventricle at end diastole that is pumped out with each contraction; normal is roughly 55 to 70 percent, and lower values indicate systolic dysfunction.

The volume of blood pumped by the heart each minute, calculated as heart rate multiplied by stroke volume; a typical resting adult value is four to eight liters per minute.

The thick middle muscular layer of the heart wall whose fibers contract to eject blood; it receives oxygen through the coronary arteries and is the tissue injured in a myocardial infarction.

The pressure inside the left ventricle at the end of filling, recorded with a pressure transducer during catheterization; it reflects filling pressures and is normally about 5 to 12 mm Hg.

A catheter-based procedure that restores flow through a narrowed or blocked coronary artery, usually by inflating a balloon and deploying a stent in a cardiac catheterization laboratory.

Inflation of a small balloon at the tip of a catheter within a coronary narrowing to crack and compress plaque and stretch the vessel wall, thereby widening the lumen.

A tiny wire-mesh tube mounted on a balloon and coated with medication that slows tissue growth; it is expanded against the vessel wall to hold the artery open and limit restenosis.

The ratio of pressure measured beyond a coronary narrowing to pressure in the aorta, recorded with a pressure-sensing guidewire during maximal blood flow; a value of 0.80 or less indicates a hemodynamically significant lesion.

A technique in which a tiny ultrasound transducer on a catheter is advanced into a coronary artery to produce cross-sectional images of the vessel wall, plaque burden, and stent expansion.

A large-lumen catheter passed through a sheath and seated at the opening of a coronary artery; it provides a stable conduit for injecting contrast and delivering guidewires, balloons, and stents.

A short plastic tube inserted into an artery or vein that remains in place during the procedure, allowing catheters and devices to be exchanged repeatedly with less trauma to the vessel.

Replacement of a diseased aortic valve by delivering a collapsible prosthetic valve through a catheter, often via the femoral artery, and expanding it within the native valve without open-chest surgery.

A balloon catheter positioned in the descending aorta that inflates during diastole to raise coronary perfusion and deflates during systole to reduce the workload of the left ventricle.

A programmable pump that delivers iodinated contrast at a set flow rate, volume, and pressure limit through a catheter, producing consistent vessel opacification while keeping staff away from the primary beam.

Acquisition of a rapid series of x-ray images, typically 15 frames per second or more, while contrast flows through the arteries; the images are stored as a loop for reviewing motion and vessel filling.

A digital method that subtracts an image acquired before contrast arrives from images acquired afterward, removing bone and soft tissue so that contrast-filled vessels stand out clearly.

A solid-state array of thin-film transistors with a photoconductor or scintillator layer that converts x-rays into an electronic image; it has largely replaced the image intensifier in modern cardiac laboratories.

A vacuum tube that converts an x-ray pattern into a bright visible-light image which a camera then records; older fluoroscopic systems use one instead of a flat-panel detector.

A feature that keeps the final fluoroscopic frame displayed after the x-ray beam stops, letting the operator study the anatomy while reducing total fluoroscopy time and dose.

A grainy, speckled appearance caused by too few x-ray photons reaching the detector, seen when exposure factors are low, the frame rate is high, or the patient is large.

Naming of fluoroscopic views by the side of the patient the detector is on and by tilt toward the head or feet; these angled views separate coronary branches that overlap in other projections.

The number of images acquired or displayed per second during fluoroscopy or cine recording; higher rates improve motion detail but increase the radiation dose delivered to the patient.

The principle that radiation exposure should be kept as low as reasonably achievable, balancing the benefit of the procedure against its risk and guiding choices of technique, collimation, and beam-on time.

The kinetic energy released by radiation in a unit mass of air, expressed in milligray; fluoroscopic equipment displays it and it is used to estimate the dose delivered to the patient's skin.

The product of the radiation dose and the area of the patient exposed, reported in gray-square centimeters; it reflects total radiation energy delivered and is used to estimate stochastic risk.

The total number of seconds the x-ray beam is on during a study; it is displayed on the equipment but only roughly predicts dose because it ignores field size, frame rate, and patient size.

Adjustment of the x-ray beam shutters to limit the exposed field to the area of interest, which sharpens the image while reducing scatter radiation and patient dose.

Fluoroscopy in which x-rays are produced in short bursts at a selected rate rather than continuously, lowering dose while still providing a usable moving image.

Acute kidney injury occurring after iodinated contrast administration and detected by a rise in serum creatinine; risk is reduced by hydration, low contrast volume, and avoiding repeated studies.

A corticosteroid regimen, sometimes combined with an antihistamine, given several hours before contrast to patients with a history of a contrast reaction in order to reduce the chance of another reaction.

Radiation injuries such as skin reddening, hair loss, or burns that appear only above a threshold dose and worsen as dose increases; prolonged high-dose fluoroscopy can produce them.