Deck 12: Multislice Spiralhelical Computed Tomography: Physical Principles and Instrumentation

Question 1

The definition of pitch in a multislice scanner, as defined by the International Electrotechnical Commission, states:

A)P = distance the table travels per rotation (d)/total collimation (W)
B)P = distance the table travels per rotation (d) + total collimation (W)
C)P = distance the table travels per rotation (d) * total collimation (W)
D)P = total collimation (W)/distance the table travels per rotation (d)

Answer 1

P = distance the table travels per rotation (d)/total collimation (W)

Question 2

Another application of the dual-source computed tomography scanner includes imaging of obese patients.

Answer 2

True

Question 3

The radiation sensors convert ___________ to ___________.

A)light; x-ray photons
B)x-ray photons; light
C)light; electrical signals
D)electric signals; light

Answer 3

x-ray photons; light

Question 4

The photodiodes convert _________ into ________.

A)light; x-ray photons
B)x-ray photons; light
C)light; electrical signals
D)electric signals; light

Question 5

A pitch greater than 1 will result in an increased dose.

Question 6

If the x-ray prepatient collimation width is 24 cm and the scanner has a four-row detector array, what is the detector row collimation?

A)4 mm
B)5 mm
C)6 mm
D)7 mm

Question 7

In multislice computed tomography, the slice thickness is determined by the: I. beam width in the z-axis
II) pitch
III) shape and width of the reconstruction filter

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

Question 8

The overall goal of multislice computed tomography is to:

A)improve volume coverage speed performance
B)decrease patient dose
C)improve spatial resolution
D)increase tube memory

Question 9

Pitch directly relates to: I. patient comfort
II) patient dose
III) volume scanned

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

Question 10

As the pitch increases, the image quality:

A)increases
B)decreases
C)does not change
D)has no direct relationship

Question 11

Which of the following describes when raw data for image reconstruction can be selected on the basis of the patient's electrocardiogram?

A)cardiac reconstruction
B)gated reconstruction
C)motion reconstruction
D)timed reconstruction

Question 12

In multislice computed tomography a _________ beam geometry results, rather than a fan beam as in single-slice computed tomography scanners.

A)circular
B)cone
C)rectangular
D)triangular

Question 13

What is the term used to describe the flipped view used for interpolated reconstruction?

A)complementary data
B)opposed data
C)opposite data
D)reciprocal data

Question 14

Some clinical benefits of subsecond scanning include: I. reduced motion artifacts
II) greater scan coverage
III) reduced patient dose

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

Question 15

To prevent anode movement under the stress of subsecond acceleration, new x-ray tubes have the anode mounted on a shaft that extends along the tube.

Question 16

Detector row collimation is equal to:

A)D (mm) + N
B)D (mm) - N
C)D (mm) *N
D)D (mm)/N

Question 17

The computed tomography detector consists of: I. radiation sensors
II) suitable electronics
III) slip rings

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

Question 18

All of the following terms are used to refer to multislice computed tomography except:

A)multisection computed tomography
B)multidetector computed tomography
C)multichannel computed tomography
D)multisystem computed tomography

Question 19

What term is used to describe the separating of the direct and complementary data trails and also results in efficient z-sampling?

A)efficient sampling scan
B)complete sampling scan
C)optimized sampling scan
D)total sampling scan

Question 20

An algorithm common in multislice computed tomography scanners is the Feldkamp-Davis-Kress algorithm.

Question 21

Which of the following are parameters of image quality? I. spatial resolution
II) contrast resolution
III) noise

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

Question 22

Which of the following are physical properties of detectors? I. high luminescence efficiency
II) large dynamic range
III) small afterglow

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

Question 23

In a multislice computed tomography scanner, what type of algorithm can be used if the number of detector rows is small?

A)cone-beam reconstruction
B)fan-beam reconstruction
C)x-axis reconstruction
D)z-axis reconstruction

Question 24

Which of the following are considered cone-beam algorithms? I. approximate algorithms
II) exact algorithms
III) opposed algorithms

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

Question 25

In 1992, the first modern multislice scanner was introduced by:

A)Elscint
B)GE Healthcare Systems
C)Siemens Healthcare Systems
D)Toshiba Healthcare Systems

Question 26

What type of detector is used in multislice computed tomography scanners?

A)helium gas detector
B)solid-state scintillation detector
C)tungsten detector
D)xenon gas detector

Question 27

The first model of the 256-slice four-dimensional computed tomography scanner was developed in:

A)2001
B)2002
C)2003
D)2004

Question 28

All of the following are materials used in solid-state detectors except:

A)calcium tungsten
B)gadolinium oxysulfide
C)gadolinium oxide
D)yttrium-gadolinium oxide

Question 29

All of the following are housed in the multislice computed tomography gantry except:

A)detectors
B)detector electronics
C)collimation selector
D)x-ray tube

Question 30

Dual-source computed tomography scanners are primarily used for:

A)cardiac imaging
B)quantitative imaging
C)pulmonary imaging
D)virtual colonoscopy

Question 31

When the slice thickness is equal to the pixel size, the data acquired are said to be:

A)anisotropic
B)distropic
C)isotropic
D)unitropic

Question 32

Which of the following is a popular tilted plane reconstruction?

A)advanced single-slice rebinning
B)helical rebinning
C)single-slice rebinning
D)tomography rebinning

Question 33

Which of the following are considered categories of approximate cone-beam algorithms? I. two-dimensional algorithms
II) three-dimensional algorithms
III) four-dimensional algorithms

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

Question 34

The computer systems of multislice computed tomography scanners have hardware that provides all of the following except:

A)high speed processing
B)image communication
C)image reconstruction
D)postprocessing operations

Question 35

What term is used to describe the number of data collection channels and the effective section thickness determined by the data acquisition system settings?

A)detector array
B)detector configuration
C)detector geometry
D)detector set

Question 36

Which of the following is/are types of detectors used in multislice computed tomography scanners? I. hybrid detectors
II) nonuniform detectors
III) uniform detectors

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

Question 37

All of the following are advantages of multislice computed tomography except:

A)increased speed and volume coverage
B)improved spatial resolution
C)reduction of radiation exposure
D)decreased contrast resolution

Question 38

The operator console controls all of the following except:

A)communication
B)control of the gantry
C)patient dose
D)windowing

Question 39

Which of the following are algorithms that were developed to reconstruct from variable slice thicknesses? I. longitudinal interpolation by z-filtering
II) spiral/helical scanning by interlaced scanning
III) spiral/helical scanning by optimized sampling

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

Question 40

What term is used to describe the resorting of the three-dimensional data collected from the cone-beam acquisition to a set of two-dimensional fan-beam data?

A)binning
B)rebinning
C)reformatting
D)sampling