CT Registry Review (MIC)
In order for an x-ray photon to be measured it must:
1. enter the detector chamber
2. be absorbed by the detector material
3. be converted to a measurable event - answer1,2,3
Which system component converts the projection attenuation data into the proper digital
form for the array processor? - answer analog-to-digital converter
Which of the following is NOT a function of a PACS system?
a. reconstruction of the image from the raw data
b. long term data storage
c. digital distribution of images
d. image display for the radiologist - answer reconstruction of the image from raw data
Which of the following is not part of the CT tube?
a. tungsten target
b. collimator
c. rotating anode
d. filament - answercollimator
Which of the following is FALSE regarding CT systems?
1. they are limited to nonoblique transverse scanning
2. they cannot generate a straight coronal or sagittal image
3. hey have no moving parts - answer1,2,3
Xrays are used in CT because:
a. they are easily produced by the high frequency generator
b. they are less harmful than the heating effects of microwave radiation
c. they penetrate the body according to specific attenuation characteristics of each
tissue
d. the FDA imposes no limit on the dose to the patient - answerC
Most of the commands from the technologists are received by the: - answeroperators
console
Xrays are produced whenever fast moving electrons collide with any form of matter
because: - answerThe electron loses kinetic energy which is converted into the
emission of an x-ray photon
The mA determines the: - answerquantity of x-ray photons
,Which of the following is a component NOT normally located in the gantry of a modern
CT system? - answerarray processor
Tube interscan delay time refers to: - answerthe time between the end of one scan and
the start of the next scan during which the tube will cool
Increased _______ will increase the likelihood that a given x-ray will penetrate a
material
1. kV
2. mA
3. exposure time - answer1
Which of the following are NOT commonly used on today's commercially available CT
scanners?
1. xenon detectors
2. fourth-generation technology
3. continous rotation technology - answer1,2
Which of the following statements is FALSE regarding occurrences after an x-ray
photon penetrates the detector aperture?
1. the photon can pass through the detector unmeasured
2. the photon is converted completely into a electron
3. the measured signal in enhanced by an amplifier - answer2
Scatter radiation is caused by: - answerdeflections from the original trajectory of an x-
ray photon through the patient
What control does the operator have over the x-rays in a CT exam? - answerthe energy
level and the quantity of x-rays can be selected
Which of the following is the standard that's used to achieve compatibility for image
transfer between various imaging modalities, viewing stations, and printers in a
hospital? - answerDICOM
The enormous heat that builds up in the CT tube is caused by what? - answerCollision
of the electron beam with the tungsten target on the tube anode
_________________ made helical imaging possible - answerContinuous rotation
scanners
The patient table:
a. may move continuously during the scan
b. can never be positioned automatically by software due to safety precautions
c. remains stationary through the exam once it is initially positioned
d. only moves after each slice is completed - answerA
,The main purpose of the detector is to: - answercapture x-ray photons and convert them
to a measurable signal
The cathode filament: - answerhelps determine the size of the focal spot
Which of the statements in TRUE:
1. kV is the voltage potential between the tube cathode and anode while mA ultimately
controls the filament temp of the cathode filament
2. kV controls the energy level of the x-ray photons and mA controls the number of x-ray
photons emitted from the tube
3. although kV and the mA affect the operation of the CT x-ray tube, the two parameters
have no bearing on the image quality - answer1,2
The number of electrons that flow from the cathode to the anode is controlled by the: -
answermA
Which of the following is TRUE regarding solid state detectors:
1. x-ray photons cause the detectors to generate a flash of light
2. they are the detector type used on most CT scanners
3. they can be used in both third-generation and fourth-generation CT systems -
answer1,2,3
The slip ring on continous rotation CT scanners:
1. prevent the high voltage cable from winding up
2. allows the exam to commence more rapidly
3. eliminates the need for the reversal of gantry frame rotation - answer1,2,3
CT is commonly referred to as all of the following except:
1. computerized axial tomography
2. digital subtraction angiography
3. CAT-scan
4. computed tomography - answer2
Which of the following CT scanner designs does NOT use an x-ray tube?
1. first generation
2. PET/CT
3. electron beam CT
4. MDCT - answer3
__________ allows remote authorized individuals to connect to a server in a secure
fashion using the routing infrastructure provided on a public network, such as the
internet. - answerVPNs (virtual private networks)
Which technology do multi-row detector scanners employ? - answerthird-generation
, Which of the following statements is FALSE regarding the collection of CT data?
1. long scan times are more desirable because they average out motion artifacts
2. reconstruction process used to create the image occurs in the array processor
3. to collect the complete st of CT data, x-rays must be passed through the body at
many different angles
4. the detectors measure the x-rays which completely penetrate the patient - answer1
On a single-row detector scanner, collimation:
1. controls the slice thickness
2. minimizes the x-ray dose to the patient
3. reduces the detection of scatter radiation - answer1,2,3
In a radiology department, a ________________ is a example of a "client" on the
network:
a. CT scanner
b. viewing console in the physicians reading room
c. printer for diagnostic images - answera,b,c
Which of the following is TRUE regarding multi-row detector for CT scanners?
1. size of the detector arrays along the z-direction may be different
2. the attenuation information from adjacent detector arrays may be added together to
generate thicker slices
3. all of the detectors arrays may or may not be used - answer1,2,3
The CT x-ray tube rotates around the patient to:
1. keep the tube cool
2. generate projection views at different angles
3. minimize the x-ray dose administered to the patient - answer2
Collimation:
1. accomplished by electrically blocking x-rays
2. affects scan time
3. limits low every x-ray photons and passed high energy photons
4. is accomplished by physically blocking x-rays - answer4
Tungsten is used as the target material on the tubes anode because it has a _________
atomic number and a _________ melting point
1. low, high
2. high, low
3. low, low
4. high,high - answer4
CT images can be directly scanned in planes other than transverse by:
1. orienting the patient's body part so that it is not perpendicular to the x-ray beam
2. tilting the gantry
3. changing the angle that the x-ray beam leaves the tube - answer1,2
In order for an x-ray photon to be measured it must:
1. enter the detector chamber
2. be absorbed by the detector material
3. be converted to a measurable event - answer1,2,3
Which system component converts the projection attenuation data into the proper digital
form for the array processor? - answer analog-to-digital converter
Which of the following is NOT a function of a PACS system?
a. reconstruction of the image from the raw data
b. long term data storage
c. digital distribution of images
d. image display for the radiologist - answer reconstruction of the image from raw data
Which of the following is not part of the CT tube?
a. tungsten target
b. collimator
c. rotating anode
d. filament - answercollimator
Which of the following is FALSE regarding CT systems?
1. they are limited to nonoblique transverse scanning
2. they cannot generate a straight coronal or sagittal image
3. hey have no moving parts - answer1,2,3
Xrays are used in CT because:
a. they are easily produced by the high frequency generator
b. they are less harmful than the heating effects of microwave radiation
c. they penetrate the body according to specific attenuation characteristics of each
tissue
d. the FDA imposes no limit on the dose to the patient - answerC
Most of the commands from the technologists are received by the: - answeroperators
console
Xrays are produced whenever fast moving electrons collide with any form of matter
because: - answerThe electron loses kinetic energy which is converted into the
emission of an x-ray photon
The mA determines the: - answerquantity of x-ray photons
,Which of the following is a component NOT normally located in the gantry of a modern
CT system? - answerarray processor
Tube interscan delay time refers to: - answerthe time between the end of one scan and
the start of the next scan during which the tube will cool
Increased _______ will increase the likelihood that a given x-ray will penetrate a
material
1. kV
2. mA
3. exposure time - answer1
Which of the following are NOT commonly used on today's commercially available CT
scanners?
1. xenon detectors
2. fourth-generation technology
3. continous rotation technology - answer1,2
Which of the following statements is FALSE regarding occurrences after an x-ray
photon penetrates the detector aperture?
1. the photon can pass through the detector unmeasured
2. the photon is converted completely into a electron
3. the measured signal in enhanced by an amplifier - answer2
Scatter radiation is caused by: - answerdeflections from the original trajectory of an x-
ray photon through the patient
What control does the operator have over the x-rays in a CT exam? - answerthe energy
level and the quantity of x-rays can be selected
Which of the following is the standard that's used to achieve compatibility for image
transfer between various imaging modalities, viewing stations, and printers in a
hospital? - answerDICOM
The enormous heat that builds up in the CT tube is caused by what? - answerCollision
of the electron beam with the tungsten target on the tube anode
_________________ made helical imaging possible - answerContinuous rotation
scanners
The patient table:
a. may move continuously during the scan
b. can never be positioned automatically by software due to safety precautions
c. remains stationary through the exam once it is initially positioned
d. only moves after each slice is completed - answerA
,The main purpose of the detector is to: - answercapture x-ray photons and convert them
to a measurable signal
The cathode filament: - answerhelps determine the size of the focal spot
Which of the statements in TRUE:
1. kV is the voltage potential between the tube cathode and anode while mA ultimately
controls the filament temp of the cathode filament
2. kV controls the energy level of the x-ray photons and mA controls the number of x-ray
photons emitted from the tube
3. although kV and the mA affect the operation of the CT x-ray tube, the two parameters
have no bearing on the image quality - answer1,2
The number of electrons that flow from the cathode to the anode is controlled by the: -
answermA
Which of the following is TRUE regarding solid state detectors:
1. x-ray photons cause the detectors to generate a flash of light
2. they are the detector type used on most CT scanners
3. they can be used in both third-generation and fourth-generation CT systems -
answer1,2,3
The slip ring on continous rotation CT scanners:
1. prevent the high voltage cable from winding up
2. allows the exam to commence more rapidly
3. eliminates the need for the reversal of gantry frame rotation - answer1,2,3
CT is commonly referred to as all of the following except:
1. computerized axial tomography
2. digital subtraction angiography
3. CAT-scan
4. computed tomography - answer2
Which of the following CT scanner designs does NOT use an x-ray tube?
1. first generation
2. PET/CT
3. electron beam CT
4. MDCT - answer3
__________ allows remote authorized individuals to connect to a server in a secure
fashion using the routing infrastructure provided on a public network, such as the
internet. - answerVPNs (virtual private networks)
Which technology do multi-row detector scanners employ? - answerthird-generation
, Which of the following statements is FALSE regarding the collection of CT data?
1. long scan times are more desirable because they average out motion artifacts
2. reconstruction process used to create the image occurs in the array processor
3. to collect the complete st of CT data, x-rays must be passed through the body at
many different angles
4. the detectors measure the x-rays which completely penetrate the patient - answer1
On a single-row detector scanner, collimation:
1. controls the slice thickness
2. minimizes the x-ray dose to the patient
3. reduces the detection of scatter radiation - answer1,2,3
In a radiology department, a ________________ is a example of a "client" on the
network:
a. CT scanner
b. viewing console in the physicians reading room
c. printer for diagnostic images - answera,b,c
Which of the following is TRUE regarding multi-row detector for CT scanners?
1. size of the detector arrays along the z-direction may be different
2. the attenuation information from adjacent detector arrays may be added together to
generate thicker slices
3. all of the detectors arrays may or may not be used - answer1,2,3
The CT x-ray tube rotates around the patient to:
1. keep the tube cool
2. generate projection views at different angles
3. minimize the x-ray dose administered to the patient - answer2
Collimation:
1. accomplished by electrically blocking x-rays
2. affects scan time
3. limits low every x-ray photons and passed high energy photons
4. is accomplished by physically blocking x-rays - answer4
Tungsten is used as the target material on the tubes anode because it has a _________
atomic number and a _________ melting point
1. low, high
2. high, low
3. low, low
4. high,high - answer4
CT images can be directly scanned in planes other than transverse by:
1. orienting the patient's body part so that it is not perpendicular to the x-ray beam
2. tilting the gantry
3. changing the angle that the x-ray beam leaves the tube - answer1,2
