Clover Fluoro 2 — Dose, Pulse Modes & Image Controls

What is the relationship between fluoroscopy beam-on time and patient dose?

Longer fluoroscopy time increases patient dose.

What is pulsed fluoroscopy?

Fluoroscopy in which the x-ray beam is delivered in short bursts rather than remaining continuously on.

Why can pulsed fluoroscopy reduce patient dose compared with continuous fluoroscopy?

The x-ray beam is off between pulses, reducing total radiation exposure.

What does PPS mean in fluoroscopy?

Pulses per second, or the number of x-ray pulses produced each second.

How does decreasing PPS affect patient dose and motion appearance?

Patient dose decreases, but motion may appear less smooth or more choppy.

How does increasing PPS affect patient dose and motion appearance?

Patient dose increases, but motion appears smoother.

What is the ALARA rule for choosing a fluoroscopic pulse or frame rate?

Use the lowest rate that still provides adequate diagnostic information.

What happens to patient dose when fluoroscopic frame rate increases?

Patient dose generally increases because more images are acquired per second.

What fluoroscopic feature allows the operator to view the previous image without another exposure?

Last-image hold.

What happens to patient dose when fluoroscopic magnification mode is selected?

Patient dose increases because the system increases radiation output to maintain adequate image brightness and quality.

What happens as fluoroscopic magnification level increases?

Image magnification increases and patient dose generally increases.

What is the purpose of a fluoroscopic noise filter?

To reduce the grainy or noisy appearance of the image.

What is a disadvantage of excessive noise filtering during fluoroscopy?

Moving anatomy may appear blurred.

What is the purpose of edge enhancement?

To make structure boundaries appear sharper and more distinct.

Does edge enhancement actually increase true spatial resolution?

No. It changes the appearance of edges through image processing.

How does high-level fluoroscopy compare with normal fluoroscopy?

High-level fluoroscopy uses greater radiation output and therefore increases patient dose and occupational scatter.

Compared with a captured fluoroscopic image, how does a digital spot image generally differ?

A digital spot image generally produces better image quality but uses a higher radiation dose.

Why does a digital spot image generally have less quantum noise than a captured fluoroscopic image?

More radiation photons are used, increasing SNR and reducing quantum noise.

What is store fluoro?

Saving fluoroscopic images that have already been produced instead of making a separate higher-dose acquisition.

How does store fluoro compare with acquisition mode?

Store fluoro generally uses less radiation, while acquisition provides higher-quality images at a higher dose.

What is Dose Area Product, or DAP?

Radiation dose multiplied by the size of the irradiated field.

What happens to DAP when field size increases?

DAP increases.

What happens to DAP when radiation dose increases?

DAP increases.

What is a common unit for DAP?

mGy·cm².

How does collimation affect DAP?

Collimation decreases field size and therefore decreases DAP.

What is the largest natural source of background radiation exposure?

Radon.

What medical imaging modality has historically contributed a large share of medical population radiation exposure?

CT.