Deck 6: Digital Fluoroscopy

Question 1

The X-ray tube used in fluoroscopy must be capable of producing X-rays either continuously or in long series.

Answer 1

False

Question 2

In digital fluoroscopy, the ADC receives the output video signal (analog signal) from the video camera.

Answer 2

True

Question 3

Recently, 43 cm x 43 cm dynamic FPD has become available for digital fluoroscopy; however, it is still not available for digital radiography.

Answer 3

False

Question 4

Which of the following changes the contrast and brightness of an image display?

A)digital fluoroscopy imaging
B)temporal frame averaging
C)digital subtraction angiography
D)grayscale-image manipulation

Question 5

____ is the continued emission of light from the screen when the radiation beam has been turned off.

A)Image lag
B)Image quality
C)Contrast ratio
D)Image intensifier

Question 6

Through the years, fluoroscopy has developed into a sophisticated imaging system as new technologies have emerged to improve its imaging system characteristics.

Question 7

The output screen is coated with a ZnCdS phosphor that converts the photoelectrons into light.

Question 8

The range of the numbers in FPDs is defined as the window level and the center of the range is defined as the window width.

Question 9

____ uses an image intensifier coupled to a video camera that converts the image from the output screen of the image intensifier into a video signal.

A)Conventional fluoroscopy
B)Fluoroscopic exposure
C)Radiography
D)Pulsed fluoroscopy

Question 10

Dynamic FPD detectors were first used in GI tract fluoroscopy and then later in angiography.

Question 11

A(n) ____ couples the video camera to the television monitor by means of a coaxial cable and control electronics.

A)X-ray tube and generator
B)closed-circuit X-ray television
C)grid-controlled X-ray tube
D)X-ray beam

Question 12

The spatial resolution for a digital fluoroscopic image depends on ____.

A)matrix format
B)mass density
C)pixel size
D)bit depth

Question 13

In fluoroscopy, a ____ converts the light from the output screen of the image intensifier into an electrical signal (output video signal), which is sent to the television monitor where it is converted into a visible image that can be viewed in real time.

A)CCD camera
B)television camera
C)closed-circuit camera
D)video camera

Question 14

Conventional fluoroscopy with an image intensifier operates in the low mA mode, and therefore the noise level is usually high.

Question 15

In digital fluoroscopy, the display image receives the video signal from the video camera and with suitable electronics, uses the signal to create the television image.

Question 16

Which of the following was developed to solve the image quality problems imposed by the fluoroscopic screen of the early fluoroscopes?

A)flat-panel digital radiography
B)computed radiography system
C)image intensifier tube
D)flat panel dynamic detector

Question 17

DSA has advanced from film-based imaging using image intensifier/video camera technology to imaging with dynamic FPDs.

Question 18

The ____ changes the image contrast and the ____ changes the brightness of the image.

A)WW; WL
B)WL; WW
C)DSA; WL
D)DSA; WW

Question 19

____ refers to the brightening of the fluoroscopic image using the image intensifier.

A)Pulsed fluoroscopy
B)Conventional fluoroscopy
C)Magnification
D)Image intensification

Question 20

In ____, a pre-contrast image referred to as a mask image is first obtained and post-contrast images are then digitally subtracted from the mask image.

A)digital subtraction angiography
B)temporal subtraction
C)temporal frame averaging
D)last-image hold

Question 21

The operational elements of a dynamic FPD involve three sequences, resulting in a single ____________________ that must be completed in at least 33 ms for fluoroscopy.

Question 22

Early fluoroscopy had to be performed in the dark using ____ for dark adaptation.

A)imaging gloves
B)red goggles
C)glass envelopes
D)black goggles

Question 23

Modern conventional fluoroscopy imaging units use a high frequency generator to ensure efficient production of ____________________.

Question 24

The exposure rate for a ____ cm mode is about 30 R/sec, while it is 60 R/sec, and 120 R/sec for the 17 cm and 12 cm modes respectively.

A)20
B)25
C)30
D)35

Question 25

Which process produces a new image that is subsequently added to the original image to produce the final image, referred to as the edge-enhanced image?

A)temporal frame averaging
B)dynamic FPDs
C)image-processing
D)subtraction

Question 26

In some systems, it is possible to adjust the pixel size by ____________________ four pixels into one larger pixel.

Question 27

Since the input screen is convex with respect to the X-ray tube, the spatial resolution is much better at the center of the input screen compared to ____.

A)the screen's magnitude
B)the screen's intensification
C)the screen's contrast
D)the screen's periphery

Question 28

In 1983, the ____________________ replaced the TV camera tube in digital fluoroscopy.

Question 29

The ____________________ ratio of an image intensifier tube is the ratio of the image brightness at the periphery to that at the center of the output screen.

Question 30

Digital fluoroscopy systems with an image intensifier and video camera (both television camera tubes and CCD cameras) in the imaging chain have been replaced with ____.

A)WLs
B)FPDs
C)DSAs
D)LEDs

Question 31

Which of the following ensures that the X-ray beam is pulsed rather than being produced continuously?

A)video camera
B)CCD camera
C)generator
D)X-ray tube

Question 32

The purpose of ____________________ frame averaging is to reduce the noise present in an image by continuously displaying an image that is created by averaging the current frame with one or more previous frames of digital fluoroscopic image data.

Question 33

Which system couples the video camera to the television monitor by means of a coaxial cable and control electronics?

A)fluoroscope imaging
B)image intensifier
C)image distributor
D)magnification

Question 34

The ____________________ operation is based on subtraction of images taken at different kVs.

Question 35

All digital imaging modalities, including digital fluoroscopy, make use of various types of image post-processing algorithms (software), essentially to manipulate the image presented to the observer in order to enhance diagnostic ____________________.

Question 36

What do conventional fluoroscopy imaging units use to ensure efficient production of X-rays?

A)image intensifier tube
B)X-ray tube
C)charge-couple device
D)high frequency generator

Question 37

While the X-ray tube and generator provide the appropriate X-ray beam for both fluoroscopy and ____________________, the image intensifier converts X-rays into light that is captured by the video camera.

Question 38

_________________ of the image in conventional fluoroscopy is an important feature of the image intensifier.

Question 39

Which of the following is an image-processing technique used to reduce the radiation dose to the patient?

A)temporal frame average
B)edge enhancement
C)last-image hold
D)grayscale-image manipulation

Question 40

The computer operates on the data it receives from the ADC in ____ format.

A)pixel
B)grayscale
C)matrix
D)digital

Question 41

The energy subtraction operation is based on subtraction of images taken at different ___________________.

Question 42

The ____________________ is a high-frequency generator and can provide the high mA values used in digital fluoroscopy, as opposed to the low mA values typical of conventional fluoroscopy.

Question 43

____________________ subtraction involves the digital subtraction of images in time.

Question 44

A pre-contrast image, referred to as a(n) ____________________ image, is first obtained and post-contrast images are then digitally subtracted from the mask image.

Question 45

The image at the output screen of the image intensifier tube is far too small and too bright to be observed directly by a(n) ____________________.

Question 46

In the case of ____________________ scanning, 262.5 odd lines (one TV field) are first scanned, followed by 262.5 even lines (one TV field).

Question 47

The image intensifier tube has been developed to replace the conventional fluorescent screen of the early ____________________.

Question 48

A digital image is made up of a matrix of pixels in which each pixel is assigned a number and each number corresponds to a(n) ____________________.

Question 49

Digital fluoroscopy can be applied to both gastrointestinal (GI) tract imaging and DSA, and the image ____________________ operations are specific to each application.

Question 50

At the heart of a digital fluoroscopy imaging system is a(n) ____________________ computer, a minicomputer system capable of receiving dynamic digital data from the ADC and processing it quickly for image display and subsequent storage.