Fluoroscopy

Question 1

Real time imaging is usually considered to be

Answer 1

30 frames per second

Question 2

Converts the absorbed incident xrays into light which in turn releases electrons

Answer 2

Input layer

Question 3

Accelerates and focuses the electrons emitted by the input layer onto output layer

Answer 3

Electron optics system

Question 4

Converts the accelerated electrons into a visible light image

Answer 4

Output phosphor

Question 5

4 different layers of the input screen include the

Answer 5

Vaccum window
Support layer
Input phosphor
Photocathode

Question 6

Thin aluminum window that is part of the vacuum containment vessel

Answer 6

Vacuum window

Question 7

Thin layer of antimony and alkali metals that emits electrons when struck by visible light

Answer 7

Photocathode

Question 8

Kinetic energy of each electron is dramatically increased by acceleration due to the voltage difference between cathode and anode, resulting in

Answer 8

Electronic gain

Question 9

Produces continuous xray beam typically using 0.5 to 6 mA

Answer 9

Continuous fluoroscopy

Question 10

With _____ fluoroscopy, the exposure time ranges from about 3-10 ms instead of 33ms, which reduces blurring from patient motion

Answer 10

Pulsed

Question 11

Offers better image quality at the same average dose rates

Answer 11

Pulsed fluoroscopy

Question 12

Continuously displays the last acquired image or set of images on the fluoroscopy monitor

Answer 12

Last frame hold

Question 13

Motorized rotation of about 220 degrees around the patient which allows two-dimensional projection images to be acquired at many different angles around the patient

Answer 13

C-arm CT

Question 14

Contrast resolution of fluoroscopy compared fo radiography is ____, chiefly due to the low SNR

Answer 14

Low

Question 15

Xray scatter from the patient is most intense on what side of the patient

Answer 15

Entrant side

Question 16

Mandatory frame rate used in cineradiography operations to capture injected contrast medium as it moves thru the vessels in the rapidly beating heart

Answer 16

High frame rate of 15-60 FPS

Question 17

Chiefly uses fluoroscopy to guide pacing and recording electrodes that are introduced into the heart to stimulate and measure the electrical properties of various cardiac control functions

Answer 17

Cardiology electrophysiology laboratory

Question 18

Systems with one patient table but with two complete imaging chains

Answer 18

Biplane angiographic systems

Question 19

Maximum permissible entrance exposure rate to the patient for normal fluoroscopy is

Answer 19

87.3 mGy/m

Question 20

For especially activated fluoroscopy, the maximum exposure rate allowable is

Answer 20

175 mGy/m

Question 21

Dose rates are evaluated in fluoroscopy by using a tissue-equivalent phantom made of a material such as

Answer 21

Polymethyl methacrylate /lucite or perspex

Question 22

Typical entrance rates for fluoroscopic detectors range from

Answer 22

8.7 to 44 nGy

Question 23

As a rule of thumb, standing 1 m from the patient the fluoroscopist recieves from scattered radiation approximately _______ of the exposure incident upon the patient

Answer 23

1/1,000

Question 24

Composed of both leakage and scatter radiation

Answer 24

Stray radiation

Question 25

It is customary to wear a single dosimeter at ____ level, _____ of the protective aron

Answer 25

Collar level, in front of the apron

Question 26

Image quality with high mA and constant kV

Answer 26

Better (lower image noise)