ARRT Cardiac-Interventional Radiography flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Left anterior descending territory

Supplies the anterior LV wall, the anterior two-thirds of the interventricular septum, and the apex; occlusion produces an anterior infarct with changes in V1–V4.

Right coronary artery supply

Supplies the right ventricle and inferior LV wall and gives the SA node branch in about 60% and the AV node branch in about 90% of people.

Coronary dominance

Determined by which artery gives rise to the posterior descending artery; right dominant in about 85%, left dominant in 8%, and codominant in 7%.

Normal ejection fraction

The fraction of LV end-diastolic volume ejected per beat, calculated as (EDV − ESV)/EDV; normal is 55–70%, and values below 40% indicate reduced systolic function.

Cardiac output formula

Cardiac output equals heart rate multiplied by stroke volume, normally 4–8 L/min; cardiac index divides output by body surface area, normal 2.5–4.0 L/min/m².

Coronary perfusion timing

Left coronary artery flow occurs predominantly during diastole; the subendocardium is most vulnerable to ischemia because tachycardia shortens the diastolic perfusion period.

Heart sound origins

S1 is produced by closure of the mitral and tricuspid valves at the onset of systole; S2 by closure of the aortic and pulmonic valves at end-systole.

Aortic stenosis severity

Severe aortic stenosis is defined by valve area under 1.0 cm², mean gradient of 40 mmHg or more, or peak velocity of 4 m/s or greater.

French catheter sizing

One French equals one-third of a millimeter; diagnostic coronary catheters are usually 4–6 Fr, while guide catheters used for intervention are 5–8 Fr.

Judkins catheter curves

Judkins left and right preformed curves engage the coronary ostia in a normal aorta; Amplatz curves are selected for dilated or tortuous ascending aortas.

Significant stenosis criteria

Angiographically, a 70% or greater diameter narrowing in a major epicardial artery, or 50% or greater in the left main, is considered flow-limiting.

FFR threshold

Fractional flow reserve of 0.80 or less across a stenosis indicates hemodynamic significance and benefit from revascularization; a value above 0.80 supports deferring intervention.

ACT target during PCI

Activated clotting time should reach 250–300 seconds with unfractionated heparin during PCI, or 200–250 seconds when a glycoprotein IIb/IIIa inhibitor is used.

TIMI flow grades

Grade 0 is no flow, 1 is faint penetration, 2 is partial filling, and 3 is normal brisk flow; TIMI 3 is the desired result after PCI.

Balloon inflation pressures

Percutaneous transluminal coronary angioplasty balloons are typically inflated to 8–14 atm; stents are deployed at manufacturer nominal pressure and post-dilated for malapposition.

Transradial access advantage

Radial artery catheterization reduces access-site bleeding and allows early ambulation; radial spasm is prevented with intra-arterial vasodilators such as nitroglycerin or verapamil.

Cine frame acquisition rate

Coronary cineangiography is usually acquired at 15 frames per second, with 30 frames per second reserved for rapid motion; pulsed fluoroscopy runs 7.5–15 frames per second.

LAO cranial projection

This view demonstrates the mid and distal left anterior descending artery and its diagonal branches, with the vessel lengthened and less foreshortened.

Foreshortening effect

A vessel appears shortened when it is not perpendicular to the x-ray beam; optimal projections place the segment of interest perpendicular to the central ray.

Magnification and dose

Reducing field of view from 20 cm to 15 cm magnifies the image but increases patient dose roughly in proportion to the square of the magnification factor.

Pixel size calculation

Pixel size equals field-of-view width divided by matrix width; a 20 cm field of view with a 1024 matrix yields pixels of approximately 0.2 mm.

Quantum mottle

Speckled image noise caused by too few x-ray photons reaching the detector; it is worsened by low dose and large patient thickness and reduced by higher detector dose.

Roadmap misregistration artifact

Roadmapping subtracts a stored mask from contrast-enhanced frames; patient, cardiac, or table motion between mask and contrast frames produces misregistration artifact.

Last image hold

The final fluoroscopic frame is retained on the monitor after exposure stops, allowing review and reducing total fluoroscopy time and radiation dose.

Occupational dose limits

NCRP annual limits are 50 mSv whole body, 150 mSv lens of the eye, and 500 mSv extremities; ICRP recommends a stricter 20 mSv annual lens limit.

Inverse square law

Scatter intensity decreases with the square of the distance from the patient; doubling the distance from the patient reduces operator dose to one quarter.

Typical angiographic effective dose

Diagnostic coronary angiography delivers roughly 3–10 mSv effective dose, while complex percutaneous coronary intervention may exceed 15 mSv.

Lead apron attenuation

A 0.5 mm lead-equivalent apron attenuates approximately 90–95% of scattered photons at typical fluoroscopic energies; lighter 0.35 mm aprons are used when justified.

Fluoroscopy dose reduction

Pulsed fluoroscopy, tight collimation, last image hold, avoidance of magnification, and keeping the detector close to the patient all lower patient and staff dose.

Radiation skin injury threshold

Transient erythema may appear at about 2 Gy absorbed skin dose and epilation at about 3–5 Gy, so cumulative dose should be tracked in prolonged procedures.

Contrast premedication regimen

For prior contrast reaction, elective premedication is prednisone 50 mg orally at 13, 7, and 1 hour before the procedure plus diphenhydramine 50 mg.

Declared pregnant worker limit

NCRP recommends a conceptus dose limit of 0.5 mSv per month and 5 mSv over the entire gestation for a declared pregnant radiation worker.