Computed Tomography: Module 2
Principles, Parameters, and Display
What are the three major components of the CT system? - correct answer ✔✔1. Gantry & patient table
2. A computer capable of processing CT date
3. An operators console
The patient table is usually made of _________ because __________ - correct answer ✔✔Carbon Fiber;
the material will absorb the least amount of radiation and support the weight of the patient
What two things does the patient table determine? - correct answer ✔✔1. Which part of patient
anatomy is scanned
2. The speed at which the patient is scanned
What setting controls the movement of the table through the gantry? - correct answer ✔✔Pitch Setting
What is the pitch setting? - correct answer ✔✔The distance the table travels during one revolution of
the tube
How is pitch expressed? - correct answer ✔✔as a ratio of table speed to slice thickness
speed:thickness
In SDCT , a pitch of ____ provided the best image quality - correct answer ✔✔1
With MDCT, how do we determine slice thickness? - correct answer ✔✔by turning on more of less
detectors as well as collimation
also by the reconstruction algorithm used after the acquisition instead of collimated beam width
, Beam pitch= - correct answer ✔✔table movement per rotation/ beam width
Increased pitch = _______ Scan speed, _______patient dose, _________ image quality - correct answer
✔✔Increased scan speed, decreased patient dose, decreased image quality
If pitch is increased by a factor of 2, what happens to patient dose? - correct answer ✔✔It is decreased
by 1/2
x-axis gantry movement refers to - correct answer ✔✔left to right movement
y-axis gantry movement refers to - correct answer ✔✔anterior to posterior movement/vertical
positioning
axis movement refers to - correct answer ✔✔superior to inferior/axial plane
All locations on the patients body are measured in - correct answer ✔✔millimeters
The gap between each coil or ridge of the helix is called a - correct answer ✔✔z-gap
as pitch decreases, z-gap ______, patient dose_____, and image quality______ - correct answer
✔✔decreases, increases, increases
What does the gantry house? - correct answer ✔✔Slip rings, Generator, Cooling system, X-ray source,
Filtration, Collimation, Detectors, data acquisition system
Most scanners can tilt - correct answer ✔✔12-30 degrees
What is the anodes speed - correct answer ✔✔3,600-10,000 rotations per minute
Principles, Parameters, and Display
What are the three major components of the CT system? - correct answer ✔✔1. Gantry & patient table
2. A computer capable of processing CT date
3. An operators console
The patient table is usually made of _________ because __________ - correct answer ✔✔Carbon Fiber;
the material will absorb the least amount of radiation and support the weight of the patient
What two things does the patient table determine? - correct answer ✔✔1. Which part of patient
anatomy is scanned
2. The speed at which the patient is scanned
What setting controls the movement of the table through the gantry? - correct answer ✔✔Pitch Setting
What is the pitch setting? - correct answer ✔✔The distance the table travels during one revolution of
the tube
How is pitch expressed? - correct answer ✔✔as a ratio of table speed to slice thickness
speed:thickness
In SDCT , a pitch of ____ provided the best image quality - correct answer ✔✔1
With MDCT, how do we determine slice thickness? - correct answer ✔✔by turning on more of less
detectors as well as collimation
also by the reconstruction algorithm used after the acquisition instead of collimated beam width
, Beam pitch= - correct answer ✔✔table movement per rotation/ beam width
Increased pitch = _______ Scan speed, _______patient dose, _________ image quality - correct answer
✔✔Increased scan speed, decreased patient dose, decreased image quality
If pitch is increased by a factor of 2, what happens to patient dose? - correct answer ✔✔It is decreased
by 1/2
x-axis gantry movement refers to - correct answer ✔✔left to right movement
y-axis gantry movement refers to - correct answer ✔✔anterior to posterior movement/vertical
positioning
axis movement refers to - correct answer ✔✔superior to inferior/axial plane
All locations on the patients body are measured in - correct answer ✔✔millimeters
The gap between each coil or ridge of the helix is called a - correct answer ✔✔z-gap
as pitch decreases, z-gap ______, patient dose_____, and image quality______ - correct answer
✔✔decreases, increases, increases
What does the gantry house? - correct answer ✔✔Slip rings, Generator, Cooling system, X-ray source,
Filtration, Collimation, Detectors, data acquisition system
Most scanners can tilt - correct answer ✔✔12-30 degrees
What is the anodes speed - correct answer ✔✔3,600-10,000 rotations per minute
