Deck 16: Computed Tomography

Question 1

Most modern CT scanners are based on _______________________ technology.

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

Answer 1

third generation

Question 2

The CT x-ray tube and detector array are found in the:

A) generation
B) gantry
C) detector
D) none of the above

Answer 2

gantry

Question 3

Slices of anatomy that go from head to foot are:

A) coronal
B) sagittal
C) axial

Answer 3

axial

Question 4

EBCT was developed to be fast enough to image the:

A) lungs
B) heart
C) diaphragm
D) skull

Question 5

Slices of anatomy that go from front to back are:

A) coronal
B) sagittal
C) axial

Question 6

This scanner uses a wide fan beam and a rotating array of detectors.

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

Question 7

This CT scanner took approximately 5 minutes to produce a single image.

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

Question 8

Using a detector array with multiple rows allows this type of scanning.

A) spiral CT
B) multislice CT
C) slip-ring technology
D) cone beam

Question 9

This is the process that allows the tube to continue rotating around the patient without the need to rewind.

A) spiral CT
B) multislice CT
C) slip-ring technology
D) cone beam

Question 10

Each major development in beam and detector geometry is called a:

A) generation
B) gantry
C) detector
D) none of the above

Question 11

This translate-rotate scanner used a single detector.

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

Question 12

The individual credited with inventing the CT scanner is:

A) Edison
B) Roentgen
C) Curie
D) Hounsfield

Question 13

Computed tomography was introduced in the:

A) 1950s
B) 1960s
C) 1970s
D) 1980s

Question 14

This translate-rotate scanner used approximately 30 detectors and a narrow fan beam.

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

Question 15

The device that absorbs the radiation and produces an electrical signal is the:

A) generation
B) gantry
C) detector
D) none of the above

Question 16

This CT scanner took approximately 30 seconds to produce a single image.

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

Question 17

This advancement has the tube rotating inside the gantry while the patient and table move through the gantry in a continuous motion.

A) spiral CT
B) multislice CT
C) slip-ring technology
D) cone beam

Question 18

Slices of anatomy that go from side to side are:

A) coronal
B) sagittal
C) axial

Question 19

This scanner uses a wide fan beam and a fixed array of detectors that encircle the patient.

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

Question 20

This is the only generation of CT scanners that used parallel beam geometry.

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

Question 21

The collimator that reduces the amount of scatter produced in the patient is the:

A) prepatient collimator
B) predetector collimator
C) A and B
D) none of the above

Question 22

For CT, the filter placed between the tube and patient is shaped like a:

A) hat
B) bowtie
C) fish
D) necktie

Question 23

The collimator that improves image contrast by limiting the amount of scatter radiation that reaches the detector is the:

A) prepatient collimator
B) predetector collimator
C) A and B
D) none of the above

Question 24

The detector found between the patient and the detectors is the:

A) prepatient collimator
B) predetector collimator
C) A and B
D) none of the above

Question 25

The CT gantry houses the:

A) x-ray tube
B) detector array
C) collimators
D) all of the above

Question 26

The snapshot of all the transmission measurements at a specific location is the:

A) view
B) ray
C) profile
D) all of the above

Question 27

For single-slice CT,this collimator controls the slice thickness.

A) prepatient collimator
B) predetector collimator
C) A and B
D) none of the above

Question 28

Another name for the CT table is the:

A) gurney
B) couch
C) board
D) all of the above

Question 29

Spiral scanning collects data for:

A) one slice at a time
B) 5-10 slices at a time
C) the entire volume of tissue being imaged
D) none of the above

Question 30

The Z axis for CT scanning goes from:

A) side to side
B) head to foot
C) back to front
D) none of the above

Question 31

The transmission value for a single detector is a:

A) view
B) ray
C) profile
D) all of the above

Question 32

As a result of using multiple rows of detectors,the x-ray beam becomes wider and is called:

A) spiral CT
B) multislice CT
C) slip-ring technology
D) cone beam

Question 33

Today's CT scanner has a detector array with a certain number of rows (4,16,64,etc. ),each with approximately _____________ detectors.

A) 50
B) 100
C) 600
D) 1000

Question 34

DAS stands for:

A) digital absorption system
B) data acquisition system
C) diode acquisition system
D) data absorption system

Question 35

This collimator is located between the tube and the patient.

A) prepatient collimator
B) predetector collimator
C) A and B
D) none of the above

Question 36

The composite electrical signal based on transmission values is the:

A) view
B) ray
C) profile
D) all of the above

Question 37

The high-frequency generator used in CT scanning has minimal voltage ripple,allowing:

A) higher kVp to be used
B) higher mA to be used
C) longer exposures
D) more consistent energy x-ray photons

Question 38

The collimator that limits the patient's radiation exposure is the:

A) prepatient collimator
B) predetector collimator
C) A and B
D) none of the above

Question 39

With multislice CT,additional rows of detectors are added along the:

A) W-axis
B) X-axis
C) Y-axis
D) Z-axis

Question 40

The x-ray tube used in CT systems has a larger-diameter anode because:

A) larger images are created with CT
B) the tube is bigger and the anode is proportional
C) CT studies produce enormous amounts of heat
D) none of the above

Question 41

This is the most common reconstruction algorithm used in CT.

A) array processor
B) algorithm
C) filtered back projection
D) image data

Question 42

The raw data is the:

A) measure of the radiation detected
B) measure of the primary radiation
C) digitized linear attenuation coefficient values
D) none of the above

Question 43

The number of rows and columns that make up the digital image is the:

A) matrix
B) pixel
C) voxel
D) voxel volume

Question 44

The small amount of tissue represented by a pixel is the:

A) matrix
B) pixel
C) voxel
D) voxel volume

Question 45

The DAS is located:

A) just below the couch
B) inside the x-ray tube
C) within the gantry
D) none of the above

Question 46

The component of the computer dedicated to performing the enormous number of calculations necessary for CT is the:

A) array processor
B) algorithm
C) filtered back projection
D) image data

Question 47

A tissue that attenuates fewer x-rays than water has a CT number:

A) 0
B) greater than 0
C) less than 0
D) unable to determine unless more is known

Question 48

A CT image typically has a ________________ matrix.

A) 64 × 64
B) 128 × 128
C) 256 × 256
D) 512 × 512

Question 49

Filtered back projection is used to analyze the _____ data for one slice to determine the ______________________.

A) raw;µ of each slice
B) raw;µ of each voxel
C) image;µ of each slice
D) image;µ of each voxel

Question 50

A tissue that attenuates more x-rays than water has a CT number:

A) 0
B) greater than 0
C) less than 0
D) unable to determine unless more is known

Question 51

The smallest component of the matrix is the:

A) matrix
B) pixel
C) voxel
D) voxel volume

Question 52

The DAS will:

A) strengthen the electrical signal
B) convert the signal to logarithmic information
C) digitize the signal
D) all of the above

Question 53

Which of the following data needs to be known to perform an attenuation calculation?

A) thickness of the part
B) age of the patient
C) anatomy being imaged
D) A and C

Question 54

The image matrix for CT is __________ than the image matrix for digital radiography.

A) smaller
B) larger
C) the same as

Question 55

Linear attenuation coefficient is symbolized by the Greek letter mu,which looks like:

A) µ
B) b
C) g
D) y

Question 56

The matrix of CT numbers is the:

A) array processor
B) algorithm
C) filtered back projection
D) image data

Question 57

The CT number of water is:

A) 0
B) greater than 0
C) less than 0
D) unable to determine unless more is known

Question 58

The sequence of computer operations for accomplishing a specific task,such as reconstruction is a(n):

A) array processor
B) algorithm
C) filtered back projection
D) image data

Question 59

Which of the following data needs to be known to perform an attenuation calculation?

A) original x-ray beam intensity
B) type of CT scanner
C) transmitted x-ray intensity
D) A and C

Question 60

This is calculated by knowing the dimensions of the pixel and the slice thickness.

A) matrix
B) pixel
C) voxel
D) voxel volume

Question 61

The midpoint of the range of CT numbers to be displayed in the image is the:

A) window level
B) window height
C) window width
D) window clearance

Question 62

The image data is the:

A) linear attenuation coefficients
B) matrix of CT numbers
C) same as the raw data
D) none of the above

Question 63

A pitch of 2 indicates that with each rotation of the tube:

A) the table is moving farther than the slice thickness
B) the table is moving less than the slice thickness
C) the table is moving the same distance as the slice thickness
D) none of the above

Question 64

Adding a printed comment or label to the image is:

A) annotation
B) windowing
C) ROI
D) MPR

Question 65

This specific area of the image is often selected to perform data analysis.

A) annotation
B) windowing
C) ROI
D) MPR

Question 66

Based on the Hounsfield scale,the CT number of air is:

A) -1000
B) 0
C) 1000
D) none of the above

Question 67

Based on the Hounsfield scale,the CT number of bone is approximately:

A) -1000
B) 0
C) 1000
D) none of the above

Question 68

Pitch ranges from:

A) 0 to 5
B) 0.5 to 2
C) 1 to 5
D) 2 to 4

Question 69

With spiral CT imaging,the relationship between slice thickness and table travel during one tube rotation is the:

A) protocol
B) SFOV
C) DFOV
D) pitch

Question 70

This refers to all the settings that must be determined for a CT imaging study.

A) protocol
B) SFOV
C) DFOV
D) pitch

Question 71

The area of anatomy seen on the monitor is the:

A) protocol
B) SFOV
C) DFOV
D) pitch

Question 72

The process that allows image data to be displayed in coronal or sagittal planes is:

A) annotation
B) windowing
C) ROI
D) MPR

Question 73

A pitch of 1 indicates that with each rotation of the tube:

A) the table is moving farther than the slice thickness
B) the table is moving less than the slice thickness
C) the table is moving the same distance as the slice thickness
D) none of the above

Question 74

The Hounsfield scale includes ___________ CT numbers.

A) 200
B) 500
C) 1000
D) 2000

Question 75

An image with a WW of 200 and a WL of 50 produces an image that displays pixels with CT numbers ranging from:

A) -100 to 100
B) -50 to 100
C) -50 to 150
D) 200 to 250

Question 76

The number of CT numbers visible in the CT image is determined by the:

A) window level
B) window height
C) window width
D) window clearance

Question 77

Determining the CT numbers that will be visible in the image is:

A) annotation
B) windowing
C) ROI
D) MPR

Question 78

The actual anatomy being imaged for the CT study is determined by the:

A) protocol
B) SFOV
C) DFOV
D) pitch

Question 79

Overlapping slices occur with a:

A) pitch of 0
B) pitch of 0.5
C) pitch of 1
D) pitch of 2

Question 80

A pitch of 0.5 indicates that with each rotation of the tube:

A) the table is moving farther than the slice thickness
B) the table is moving less than the slice thickness
C) the table is moving the same distance as the slice thickness
D) none of the above