Deck 5: Data Acquisition Concepts

Question 1

The configuration of the dual-row detector system results in faster volume coverage compared with single-row computed tomography systems.

Answer 1

True

Question 2

The total number of data samples per scan or per slice in computed tomography is the:

A)number of data samples per view times the number of views
B)number of views
C)number of detectors plus the number of data samples per detector
D)number of data samples per view plus the number of views

Answer 2

number of data samples per view times the number of views

Question 3

Streaking artifacts are the result of too many samples being measured by the detectors.

Answer 3

False

Question 4

Gas ionization computed tomography detectors convert x ray photons into electrical signals with no light conversion process in between.

Question 5

A single ray in computed tomography is:

A)a beam of x rays emanating from the x-ray tube
B)a single straight line path of an x-ray beam
C)the total attenuation as measured by the detector
D)a collection of beams gathered by the detector

Question 6

Optoelectronics refers to the use of lens and light diodes to facilitate data transmission.

Question 7

The high-voltage generators of slip-ring scanners are located in the gantry.

Question 8

The overall goal of the electron-beam computed tomography scanner is to produce low-resolution images of moving organs that are free of artifacts caused by motion.

Question 9

Which of the following refers to a method by which the patient is systematically scanned by the x-ray tube and detectors to collect enough information for image reconstruction?

A)beam geometry
B)data acquisition
C)sampling
D)projection reconstruction

Question 10

Which computed tomography scanner is based on a fan beam geometry and complete rotation of the x-ray tube and detectors?

A)first-generation scanner
B)second-generation scanner
C)third-generation scanner
D)fourth-generation scanner

Question 11

Seventh-generation scanners use flat-panel digital area detectors.

Question 12

Multirow computed tomography detectors fall into two categories, namely, matrix array detectors and pixel array detectors.

Question 13

Photodiodes are now used in computed tomography scintillation detectors.

Question 14

Which of the following refers to the size, shape, motion, and path traced by the x-ray beam as it scans the patient?

A)beam geometry
B)projection profile
C)data acquisition
D)detector tracing

Question 15

A view in computed tomography is:

A)a specific way in which the patient is positioned with respect to the detectors
B)the total attenuation as measured by the detector
C)a collection of rays for one translation across the object
D)a single straight line path of an x-ray beam

Question 16

Scintillation detectors convert x-ray photons to light and subsequently to electrical signals.

Question 17

Gas ionization chambers were first introduced in second-generation scanners.

Question 18

Computed tomography detectors generate a signal that represents the attenuation as the ray moves across the slice. This signal is called:

A)a view sample
B)an acquisition sample
C)a profile
D)a data sample

Question 19

The change of attenuation and thickness data into transmission measurement is called efficiency conversion.

Question 20

The Stanton x-ray tube was designed by Toshiba Medical Systems.

Question 21

In one type of fourth-generation computed tomography scanner, the tilting action of the detector ring is referred to as:

A)slip-ring technology
B)nutating
C)spiral scanning
D)helical scanning

Question 22

The slice thickness in computed tomography is determined by the:

A)radiologist
B)technologist
C)collimator height
D)collimator width

Question 23

Which of the following refers to the ability of the computed tomography detector to capture, absorb, and convert x-ray photons into electrical energy?

A)efficiency
B)stability
C)response time
D)dynamic range

Question 24

The speed with which a computed tomography detector can detect an x-ray event and recover to detect another event is the:

A)response time
B)stability
C)efficiency
D)dynamic range

Question 25

Which scanner allows for continuous rotation of the x-ray tube while the patient moves simultaneously through the gantry aperture?

A)third-generation conventional scanner
B)fourth-generation conventional scanner
C)spiral/helical scanner
D)dynamic volume scanner

Question 26

Which x-ray generator is used in modern computed tomography scanners?

A)single-phase half-wave rectified
B)single-phase full-wave rectified
C)high-frequency generator
D)three-phase, six-pulse generator

Question 27

Compared with conventional computed tomography scanners, slip-ring scanners offer the following advantage(s): I. removal of cable wraparound
II) elimination of start-stop action
III) continuous rotation of x-ray tube and minimal interscan delays

A)I and II
B)II and III
C)I and III
D)I, II, and III

Question 28

Which of the following x-ray tubes is most likely used in spiral/helical computed tomography scanners?

A)a tungsten target fixed anode tube
B)a tungsten target rotating anode tube
C)a molybdenum target rotating anode tube
D)a rotating anode tube with a rhenium tungsten disk

Question 29

Which of the following is classified as a high-speed computed tomography scanner?

A)third-generation scanner
B)fourth-generation scanner
C)spiral/helical computed tomography scanner
D)fifth-generation CT scanner

Question 30

In which scanner is the apex of the fan beam located outside the detector?

A)third-generation scanner
B)fourth-generation scanner
C)fifth-generation scanner
D)sixth-generation scanner

Question 31

The purpose of collimation in computed tomography is: I. to protect the patient
II) to ensure a constant beam width at the detector
III) to reduce scatter radiation

A)I and II
B)II and III
C)I and III
D)I, II, and III

Question 32

Electromechanical devices made up of rings and brushes to transmit electrical energy across a rotating interface are called:

A)target rings
B)slip rings
C)spiral rings
D)helical rings

Question 33

Which generation of scanners, also called dual-source computed tomography scanners, consists of two x-ray tubes and two sets of detectors?

A)third generation
B)fourth generation
C)fifth generation
D)sixth generation

Question 34

Which scanner is based on slip-ring technology?

A)third-generation conventional scanner
B)fourth-generation conventional scanner
C)spiral/helical scanner
D)fifth-generation scanner

Question 35

The scanner that uses an electron gun to "shoot" electrons toward a target ring is the:

A)fifth-generation scanner
B)fourth-generation scanner
C)third-generation scanner
D)spiral/helical scanner

Question 36

Which scanner results in a volume of the patient being scanned during a single breath hold (rather than a single slice of tissue)?

A)spiral/helical scanner
B)fifth-generation scanner
C)second-generation scanner
D)first-generation scanner

Question 37

All of the following are radiation beams produced by an x-ray tube designed for computed tomography except:

A)homogeneous beam
B)heterogeneous beam
C)polychromatic beam
D)polyenergetic beam

Question 38

The main purpose of a filter used in computed tomography is to:

A)reduce the intensity of the beam at the detector
B)make the beam less uniform at the detector
C)decrease the mean energy at the detector
D)protect the patient

Question 39

Fourth-generation computed tomography scanners are characterized by:

A)rotate-translate motion and parallel beam geometry
B)rotate-translate motion and fan beam geometry
C)fan beam geometry and continuous rotation of x-ray tube and detectors
D)fan beam geometry and complete rotation of x-ray tube around a stationary ring of detectors

Question 40

Which detector characteristic refers to the steadiness of the detector response?

A)efficiency
B)stability
C)response time
D)dynamic range

Question 41

Please match the following data acquisition concepts. All answer selections will be used just once.

Collimation

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 42

Please match the following data acquisition concepts. All answer selections will be used just once.

Slip-ring design

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 43

Please match the following data acquisition concepts. All answer selections will be used just once.

Semiconductor

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 44

Please match the following data acquisition concepts. All answer selections will be used just once.

Ionization detector

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 45

Which of the following is commonly used in gas ionization computed tomography detectors?

A)xenon
B)oxygen
C)neon
D)helium

Question 46

Please match the following data acquisition concepts. All answer selections will be used just once.

Filtration

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 47

Please match the following data acquisition concepts. All answer selections will be used just once.

Detector electronics

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 48

Please match the following data acquisition concepts. All answer selections will be used just once.

Scintillation

A)Data acquisition system
B)Flashes of light
C)Beam hardening
D)Xenon gas
E)Slice thickness
F)Photodiode
G)Continuous gantry rotation

Question 49

The ratio of the largest signal to the smallest signal measured by a computed tomography detector is the:

A)response time
B)dynamic range
C)efficiency
D)stability

Question 50

The following crystals have been used in scintillation computed tomography detectors except:

A)bismuth germinate
B)calcium tungstate
C)calcium fluoride
D)sodium iodide