Ch. 36 Fluoroscopy (Exp II)

Question 1

Fluoroscopy is a _______ x-ray examination

Answer 1

Dynamic, real-time

Question 2

Fluoroscopy is the domain of the _______

Answer 2

Radiologist

Question 3

Fluoroscopy is commonly used for observation of…

Answer 3

• Cardiovascular structures
• Surgical procedures
• The GI tract

Question 4

The fluoroscopic X-ray tube and image receptor are mounted _______

Answer 4

Coincident to each other

Question 5

The fluoroscopic carriage commonly supports the _______

Answer 5

• IR
• Power-assist drive controls
• Digital spot film selector

Question 6

Fluoroscopic mA range is commonly _______

Answer 6

0.5-5 mA

Question 7

During fluoroscopy, the SOD on a fixed unit cannot be less than _______ inches.

Answer 7

15

Question 8

During fluoroscopic image intensification, the primary x-ray beam exits the patient and strokes the _______ of the image intensifier.

Answer 8

Input screen

Question 9

The input screen absorbs _______ and emits _______.

Answer 9

X-ray photons; light photons

Question 10

The photocathode absorbs _______ and emits _______.

Answer 10

Light photons; electrons

Question 11

Electrostatic lenses are used to accelerate and focus _______.

Answer 11

Electrons

Question 12

The primary _______ occurs from the acceleration and focusing of the electron beam.

Answer 12

Brightness gain

Question 13

The output screen absorbs _______ and emits _______.

Answer 13

Electrons; light photons

Question 14

The input screen is _______ in shape.

Answer 14

Concave

Question 15

The shape of the input screen helps to control _______.

Answer 15

Distortion

Question 16

The photocathode is composed of _______ metals.

Answer 16

Photoemissive

Question 17

Photoemissive materials absorb _______ and emit _______.

Answer 17

Light photons; electrons

Question 18

Electrostatic lenses are actually _______

Answer 18

Charged electrodes

Question 19

The greater the voltage supplied to the electrostatic lenses, the _______ the acceleration and the _______ the focal point to the input screen.

Answer 19

Greater; closer

Question 20

Total brightness gain is…

Answer 20

• A measure of the increase in image intensity
• Determined by minification gain
• Determined by flux gain

Question 21

Fluoroscopic resolution with image intensification will vary according to…

Answer 21

• Minification gain
• Electrostatic focal point
• Input and output screen diameter

Question 22

The edge distortion problem in image intensification tubes is called _______.

Answer 22

Vignetting

Question 23

The most common solution for quantum mottle is to _______.

Answer 23

Increase the fluoro tube mA

Question 24

The most commonly used fluoroscopic viewing system is _______.

Answer 24

Real-time video monitors

Question 25

Cassette-based spot filming has been replaced by _______.

Answer 25

Digital photo spots

Question 26

Digitization of he fluoroscopic image permits...

Answer 26

- Image post processing - Transfer via PACS - Electronic archival

Question 27

Digital fluoro pixels are between _______ micrometers.

Answer 27

200 and 300

Question 28

Flat panel digital detectors used for fluoroscopy use...

Answer 28

- Amorphous silicon as the digital detector - A cesium iodide scintillator - TFT technology

Question 29

In order to reduce visible noise using digital fluoroscopic detectors, _______

Answer 29

Pixels are binned

Question 30

All of the following are common post processing features with digital fluoroscopy except... A. Last image hold (LIH) B. Digital subtraction C. Window level and width D. Edge enhancement

Answer 30

A. Last image hold (LIH)

Question 31

During fluoroscopy, the principal source of radiation exposure to personnel in the room is the _______.

Answer 31

Patient

Question 32

In a fluoroscopy system, the X-ray tube and IR must be interlocked in order to enable fluoroscopy. This classifies the IR as the _______.

Answer 32

Primary barrier

Question 33

All of the following are true of the fluoroscopic lead apron drape except: A. It should be 0.25 mm Pb equivalent B. It is designed to absorb a large percentage of patient scatter C. It covers the Bucky slot in the table D. It may detach for specific cases

Answer 33

C. It covers the Bucky slot in the table

Question 34

Methods to reduce fluoroscopic radiation exposure include:

Answer 34

- Automatic Brightness Control - Bucky tray slot cover - Fluoroscopic lead apron drape - Dead-man type fluoroscopy switch - Last Image Hold (LIH) - Decrease the IOD

Question 35

Digital fluoroscopy is typically...

Answer 35

- A progressive, pulsed fluoroscopic exposure - capable of producing highly contrast images - Capable of 256 shades of gray through 8-bit processing

Question 36

_______ deals with the gain resulting from the conversion of light at the output phosphor.

Answer 36

Flux gain

Question 37

Mobile fluoroscopic systems are different from fixed systems in that they...

Answer 37

Have a minimum SOD of 12 inches

Question 38

When using automatic brightness control (ABC), it is important to remember that

Answer 38

A dark video image indicates photon starvation to the receptor

Question 39

Digital fluoroscopy typically...

Answer 39

- Uses pulsed x-ray exposures timed with the detector - Uses indirect detector technology with thin film transistors (TFT) - Provides resolution of 1-2 lp/mm

Question 40

The fluoroscopic X-ray tube is different from a radiographic tube in that the fluoro tube...

Answer 40

Cannot have an SOD of less than 15 inches