ST:10(PET/CT) Flashcards
Which of the following positron emitting radionuclides is ONLY cyclotron produced:
a. Nitrogen-13
b. Gallium-68
c. Rubidium-82
d. Copper-62
a. Nitrogen-13
Property of PET detectors that allows them faster timing signal for coincidence detection and to work at high count rates is called:
a. The stopping power
b. The decay constant
c. Energy resolution
d. The light output
b. The decay constant
A substitution radioactive for nonradioactive element in a biologically active PET tracer molecule without altering its biological properties is called:
a. Hot for hot substitution
b. Hot for cold substitution
c. Cold for hot substitution
d. Cold for cold substitution
b. Hot for cold substitution
The inverse of the mean distance traveled by photons before they deposit energy in the crystal is called:
a. Light output
b. Decay constant
c. Energy resolution
d. Stopping power
d. Stopping power
The exposure rate of ac activity of 1 millicurie measured at 1 centimeter is called:
a. Roentgen man equivalent (REM)
b. Total effective dose equivalent (TEDE)
c. The exposure rate constant (ERC)
d. Kilobequerel (kBq)
c. The exposure rate constant (ERC)
Diaphragmatic crus F-18 FDG uptake can be seen in patients with:
a. Increased respiratory effort
b. Tachycardia
c. Malignancy
d. Anxiety
a. Increased respiratory effort
Administration of water-equivalent contrast agent when performing PET/CT imaging:
a. Underestimates SUV
b. Produces streaking artifact
c. Has no effect of SUV
d. Overestimates SUV
c. Has no effect of SUV
DNA synthesis is a measure of cellular:
a. Apoptosis
b. Proliferation
c. Mutation
d. Metabolism
b. Proliferation
Brain metabolism and blood flow are increased at the site of onset of the seizure in the:
a. Inter and intraictal states
b. Neither inter and intraictal states
c. Interictal state
d. Intraictal state
d. Intraictal state
The pattern of diffuse hypermetabolism in the skeleton and the spleen on PET FDG study is most likely caused by:
a. Excessive exercise
b. Bone marrow hyperplasia
c. Prolonged fasting
d. Bone metastases
b. Bone marrow hyperplasia
Stunned or hibernating myocardium is:
a. Dysfunctional but viable
b. Functional
c. Nonviable
d. Dysfunctional and nonviable
a. Dysfunctional but viable
Bilateral symmetric decreased FDG uptake in the temporoparietal region of the brain is the prevailing pattern observed in:
a. Vascular dementia
b. Alzheimers disease
c. Dementia with lewy bodies
d. Pick disease
b. Alzheimer’s disease
Which of the following types of non-Hodgkins lymphomas is most common:
a. Burkitts lymphoma
b. Diffused large B cell lymphoma
c. Lymphoblastic lymphoma
d. Anaplastic T cell lymphoma
b. Diffused large B cell lymphoma
Rb-82 is a monovalent catiotic analog of potassium and has a biologic activity similar to:
a. Tl-201
b. F-18
c. Tc-99m
d. Ga-67
a. Tl-201
Which of the following radionuclides commonly used in PET imaging has the lowest positron range in water:
a. Fluorine-18
b. Carbon-11
c. Nitrogen-13
d. Oxygen-15
a. Fluorine-18
QC testing for PET agents that involves decay analysis in a dose calibrator for a defined period of time is called:
a. Specific activity analysis
b. Radiochemical purity
c. Bacterial endotoxin testing
d. Radionuclidic identity
d. Radionuclidic identity
Truncation artifacts in PET/CT imaging are produced by:
a. Difference in size of FOV between PET and the CT
b. Beds overlapping
c. Contrast medium
d. Difference in scanning time between PET and CT
a. Difference in size of FOV between PET and the CT
The first PET radiopharmaceutical to receive USDA approval in 1989 was:
a. F-18 Fluoride
b. F-18 FDG
c. N-13 Ammonia
d. Rb-82
d. Rb-82
Which of the following radionuclides commonly used in PET images has the highest positron energy:
a. Nitrogen-13
b. Oxygen-15
c. Fluorine-18
d. Carbon-11
b. Oxygen-15
Ovarian uptake of F-18 FDG in a postmenopausal patient indicates:
a. Normal finding
b. Malignancy
c. Pregnancy
d. Ovulation
b. Malignancy
An area of focal FDG uptake in the lungs, without corresponding findings on CT most likely represents:
a. An injected blood clot
b. Rib fracture
c. Radiation necrosis
d. Pulmonary nodule
a. An injected blood clot
Linear attenuation coefficient determines the scintillator:
a. Energy resolution
b. Stopping power
c. Light output
d. Decay constant
b. Stopping power
The sum of the weighted equivalent doses in all the tissues and organs of the body is called:
a. Whole body dose
b. Effective dose
c. Shallow dose equivalent
d. Committed dose equivalent
b. Effective dose
Multiple focal cortical and subcortical defects on FDG study indicates diagnosis of:
a. Alzheimer’s disease
b. Vascular dementia
c. Parkinson’s disease
d. Radiation necrosis
b. Vascular dementia
Two photons arising from the same annihilation event and detected by two detectors within the coincidence time window are:
a. Single events
b. Scatter coincidence
c. Random events
d. True coincidence
d. True coincidence
How can partial volume averaging be reduced:
a. Using a half-scan algorithm
b. Scanning with thicker slices
c. Scanning with thinner slices
d. B and C are correct
c. Scanning with thinner slices
Which of the following is the most effective type of CT detector:
a. Linear array
b. Photodiode
c. Xenon gas
d. Scintillation
d. Scintillation
Which of the following are functions to the patient table: (1) contributed to patient safety (2) enhances subject contrast (3) transports the patient through the gantry:
a. 1 and 2
b. 2 and 3
c. 1 and 3
d. 1, 2 and 3
c. 1 and 3
Radiopaque non-ionic contrast agents are considered safe for pregnant patients:
a. True
b. False
a. True
The scout (topogram) image for a CT of the head must include _____ through the vertex of the skull:
a. The external auditory meatus (EAM)
b. C2
c. C1
d. Floor of the orbits
c. C1
As the display field of view (DFOV) decreases: (1) noise increases (2) spatial resolution increases (3) spatial resolution decreases:
a. 1 and 2
b. 1, 2 and 3
c. 1 and 3
d. 2 and 3
a. 1 and 2
Edge gradient artifacts appear as a:
a. Streak
b. White circles
c. Ring
d. Band of noise across the image
a. Streak
Back-projection is associated with:
a. Artifacts
b. Helical/spiral scanning
c. Increased image sharpness
d. Pitch
a. Artifacts
When the x, y, and z planes (length, width, and height) are equal, the volume data set is:
a. Isotropic
b. Anisotropic
c. Rectangle-shaped
d. Linear
a. Isotropic
The National Council on Radiation Protection and Measurements (NCRP) recommends that the annual occupational dose for imaging professionals not exceed:
a. 5 mSv
b. 50 mSv
c. 1 Sv
d. 1 mSv
b. 50 mSv
In multi-slice CT scanners, detector systems with equal size detector elements are called _____ arrays:
a. Symmetric
b. Adaptive
c. Linear
d. Curved
a. Symmetric
Image noise can be reduced by:
a. Decreasing pixel size
b. Decreasing slice thickness
c. B and C are correct
d. Increasing mAs
d. Increasing mAs
Which generation of CT scanners is associated with the term “EBCT” and the use of an electron beam gun:
a. 4th
b. 6th
c. 7th
d. 5th
d. 5th
Spiral-helical scanners incorporate _____ slip rings:
a. High and low voltage
b. High voltage
c. Low voltage
d. No choice is correct
a. High and low voltage
Virtual reality (VR) and volume rendering imaging techniques are identical
a. True
b. False
b. False
Which of the following workstation applications would most likely be used by cardiologists:
a. Ejection fraction and calcium scoring
b. Ejection fraction, calcium scoring, and stereotaxis
c. Ejection fraction and stereotaxis
d. Calcium scoring and stereotaxis
a. Ejection fraction and calcium scoring
Which of the following factors decreases contrast resolution:
a. Smaller matrix size
b. Higher mAs
c. Smaller field of view
d. Smaller pixel size
d. Smaller pixel size
First generation CT scanners used ______ beam scanning:
a. Pinpoint
b. Cone
c. Pencil
d. Fan
c. Pencil
Which of the following is considered a secondary protective radiation barrier:
a. Lead apron
b. CT control room walls
c. Protective glass
d. Thyroid shield
b. CT control room walls
The CT Dose Index (CTDI) is most accurate when applied to:
a. Helical/spiral scanners
b. Single slice scanners
c. Multi-slice scanners
b. Single slice scanners
Xenon studies are most closely associated with:
a. Neurology studies
b. Cardiology studies
c. Radiation oncology treatment planning
d. Virtual reality (VR) colonography
a. Neurology studies
To achieve optimum detail and the thinnest slice possible, modern spiral helical CT scanner x-ray tubes contain only one filament/focal spot:
a. True
b. False
b. False
The term “translation” is associated with _____ generation scanners:
a. 1st
b. 2nd
c. 3rd
d. A and B are correct
d. A and B are correct
As pitch increases, patient dose:
a. Is unaffected
b. Increases
c. Decreases
c. Decreases
Sampling occurs at the:
a. Digital to analog converted (DAC)
b. CT detectors
c. Pre-patient collimators
d. Analog to digital converters (ADC)
b. CT detectors
Which of the following detector types produces higher quality images:
a. Scintillation
b. Linear
c. Gas
a. Scintillation
To assure fast scan times and immediate data processing, CT computers depend on:
a. Multiprocessing
b. Distributed processing
c. Parallel processing
d. Multitasking
c. Parallel processing
Beam-shaping filters are generally composed of:
a. Copper
b. A and C are correct
c. Aluminum
d. Teflon
b. A and C are correct
Cupping artifacts are most closely related to which image quality:
a. Contrast resolution
b. Temporal resolution
c. Uniformity
d. Linearity
c. Uniformity
A CT gantry includes all of the following components except:
a. Detectors
b. Bow tie filters
c. Collimators
d. Central processing unit
d. Central processing unit
What is the window level if the CT/Hounsfield range is 200 to 1000:
a. 800
b. 400
c. 500
d. 600
d. 600
Window Level also called window center would be the center number between 200 and 1000.
1000-200= 800 then 800/2= 400 so 600 is answer.
Which of the following terms is also referred to as a convolution algorithm:
a. Kernel
b. Ring artifact
c. Interpolation
d. Iterative algorithm
a. Kernel
First generation scanners were only capable of imaging the:
a. Head/brain
b. A and B are correct
c. Extremities
d. Chest, abdomen, and pelvis
a. Head/brain
Patients taking metformin should stop taking the medication _____ hours after IV contrast media injection:
a. 72
b. 48
c. 24
d. 12
b. 48
Which of the following most closely approximates the actual radiation dose to a specific patient for a specific exam:
a. MultiScan Average Dose (MSAD)
b. CTDI
c. Dose Length Product (DLP)
c. Dose Length Product (DLP)
For a spiral/helical head CT scan using a multi-detector configuration, the recommended pitch is:
a. 1 to 1.7
b. 0.7 to 1.0
c. 0.7 to 1.2
d. 1 to 1.2
b. 0.7 to 1.0
Which type of post-processing technique would most likely be used for CT virtual colonography exams:
a. Shaded surface rendering
b. MIP (Maximum Intensity Projection)
c. Volume rendering
d. minIP (Minimum Intensity Projection)
d. minIP
Which of the following medications most likely would be used to treat chest pain caused by angina:
a. Dopamine
b. Naloxone
c. Nitroglycerin
d. SoluMedrol
c. Nitroglycerin
In sixth generation CT scanners, which of the following elements rotate around the patient:
a. The x-ray tube
b. Detectors
c. No choices are correct
d. X-ray tube and detectors
d. X-ray tube and detectors
The data acquisition system (DAS) is located:
a. Between the detectors and the analog to digital converter (ADC)
b. Between the detectors and the computer
c. In the gantry
d. Between the detectors and the analog converts (DAC)
b. Between the detectors and the computer
Which of the following is a filtering technique in which the reformatted raw data are copies to create what looks like the original raw data set:
a. Multi planar reconstruction
b. Convolution
c. Sectional reformatting
d. Kernel
b. Convolution
Which of the following would normally not be used to administer contrast with a power injector:
a. Perma-cath
b. Power PICC line
c. A and B are correct
d. Power Port-A-Cath
a. Perma-cath
CT scanner x-ray tube voltages range from ____ to _____ kilovolts (kV):
a. 80; 140
b. 60; 100
c. 100; 160
d. 80; 120
a. 80; 140
For a routine abdomen/pelvis CT scan, the recommended SFOV is ____ cm:
a. 25
b. 50
c. 65
d. 75
b. 50
CT scanner x-ray tubes incorporate rotating anodes composed of:
a. Tungsten, molybdenum and rhenium
b. Rhenium, tungsten and rhodium
c. Tungsten, copper and molybdenum
d. Molybdenum, tungsten and rhodium
a. Tungsten, molybdenum and rhenium
Which of the following medications may be used to prevent nephrotoxicity:
a. Glucophage
b. Metformin
c. Diphenhydramine
d. Acetylcysteine
d. Acetylcysteine
Which of the following devices is the most accurate monitor used to measure occupational radiation exposure:
a. Optically stimulated luminescent dosimeter
b. Geiger counter
c. Film badge
d. Thermoluminescent dosimeter
a. Optically stimulated luminescent dosimeter
When a spiral-helical CT scanner takes a scout image, the x-ray tube:
a. Rotates around the patient
b. Is stationary
c. Can take a frontal and lateral projection at the same time
b. Is stationary
Which of the following conditions is an indication for a CT scan of the head WITHOUT intravenous (IV) contrast:
a. Metastatic disease
b. Stroke
c. Aneurysm
d. Arteriovenous malformation
b. Stroke
In a ______ CT scanner, the x-ray tube rotates continuously around the patient as the patient travels through the gantry:
a. Helical/spiral
b. Axial
c. Third-generation
d. High-speed
a. Helical/spiral
Which of the following includes a sampler, quantizer and a coder:
a. DAC
b. ADC
c. DAS
d. Detector array
b. ADC
Linear attenuation coefficients are directly related to:
a. Patient dose
b. Helical/spiral scanners only
c. Axial scanners only
d. Attenuation
d. Attenuation
A pitch of _____ results in the highest dose to the patient:
a. Pitch does not affect patient dose
b. Less than 1
c. 1
d. 2
b. Less than 1
Which of the following techniques requires 100% of the data set for postprocessing:
a. Minimum intensity projection (minIP)
b. Volume rendering
c. Shaded surface rendering
d. MIP
b. Volume rendering
For a routine thoracic/lumbar CT scan of an adult patient, the recommended SFOV is ______ cm and the recommended DFOV is _____ cm:
a. 50; 50
b. 50; 12-20
c. 25; 25
d. 25; 12-20
b. 50; 12-20
Which of the following image manipulation tools is most useful for viewing 3D images:
a. Zoom
b. Scroll
c. Swivel
d. Pan
c. Swivel
For a routine abdomen/pelvis CT, the recommended WW/WL is:
a. WW 1500; WL 600
b. WW 600; WL 1500
c. WW 350-400; WL 40-60
d. WW 40-60; WL 350-400
c. WW 350-400; WL 40-60
Which of the following types of CT scanners are capable of effectively imaging a beating heart:
a. 15 slice and 64 slice
b. 64 slice and 128 slice
c. 16 slice and 128 slice
d. 16 slice, 64 slice, and 128 slice
b. 64 slice and 128 slice
Modern multi-slice CT scanners use _____ geometry:
a. Fan bean
b. Pencil thin beam
c. Parallel beam
d. Cone beam
d. Cone beam
Tube arcing occurs:
a. Insides the x-ray tube and because of fluctuations in line voltage
b. Inside the x-ray tube and outside the x-ray tube
c. Outside the x-ray tube and because of fluctuations in line voltage
d. Inside the x-ray tube, outside the x-ray tube, and because of fluctuations in line voltage
b. Inside the x-ray tube and outside the x-ray tube
Window level (WL) refers to: (1) the midpoint in a range of CT numbers (2) image contrast (3) image brightness:
a. 1 and 2
b. 1, 2 and 3
c. 2 and 3
d. 1 and 3
d. 1 and 3
What does the Fourier transform calculate:
a. Attenuation to detector time
b. Patient dose
c. Convolution
d. Projection data
a. Attenuation to detector time
Tube arcing appears as a:
a. Streak artifact
b. Ring artifact
c. Cone bean artifact
d. Band of increased noise across the image
d. Band of increased noise across the image
Modern CT scanners have x-ray tubes designed to withstand large amounts of heat. The anode on these tubes includes a target made of:
a. Molybdenum
b. Tungsten
c. Copper
d. Rhodium
b. Tungsten
A CT scanner with 16 detector rows, each scanning 4 widths, is called a _____-slice scanner:
a. 64
b. 8
c. 16
d. 4
a. 64
For optimum enhancement of blood vessels and organs on a routine abdomen/pelvis CT scan, the average adult patient should receive ____ mL of IV contrast:
a. 200
b. 150 to 175
c. 50 to 100
d. 100 to 150
d. 100 to 150
Which of the following is not a common contrast injection reaction:
a. Dyspnea
b. Metallic taste
c. Flushed feeling in the pelvis
d. Pain at the injection site
a. Dyspnea
Ring artifacts only appear in _____ scanners:
a. 3rd generation
b. 2nd generation
c. Multi-slice
d. 1st generation
a. 3rd generation
Overlap occurs when the pitch is less than:
a. Overlap is not related to pitch
b. 1.5
c. 0.5
d. 1.0
d. 1.0
Compared to barium used for regular fluoroscopy procedures, the barium used for CT procedures is:
a. More dense
b. Less dense
c. Of the same density
b. Less dense
Cone beam artifacts only appear in _____ scanners:
a. 1st generation
b. Multi-slice
c. 2nd generation
d. 3rd generation
b. Multi-slice
Which of the following tests uses a solid plastic phantom with two holes drilled into it at 90 degree angles to for an “X”:
a. CT numbers calibration
b. High contrast resolution
c. Localization device accuracy
d. Low contrast resolution
c. Localization device accuracy
All spiral-helical scanners incorporate copper brushes as a component of the slip-ring design:
a. True
b. False
b. False
Which of the following processes is associated with reconstructing volumetric acquired data to make the data look like individual slices:
a. Pitch
b. Filtering
c. Linear interpolation
d. Back-projection
c. Linear interpolation
A digital to analog converter is needed to:
a. Display data on a LCD monitor
b. Transform the electric signal to light
c. Change the remnant beam to an electric signal
d. Encode transmitted radiation into binary data
a. Display data on a LCD monitor
To view a CT image on a LCD monitor, data must undergo:
a. Digitization
b. Analog to digital conversion
c. Digital to analog conversion
d. Quantization
c. Digital to analog conversion
Volume acquisition scanners are based on; (1) slice by slice data acquisition (2) slip ring technology (3) continuous rotation of the x-ray tube:
a. 2 and 3
b. 1, 2 and 3
c. 1 and 2
d. 1 and 3
a. 2 and 3
Filtered back projection is most closely associated with
a. Artifact free images
b. Ring artifacts
c. Aliasing artifacts
d. Misregistration
a. Artifact free images
With respect to detectors, the term “dynamic range” refers to:
a. Detector consistency
b. No choice is correct
c. How efficiently the detectors gather the photons coming from the patient
d. The accuracy of response to low and high energy radiation
d. The accuracy of response to low and high energy radiation
A smoothing filter is applied to scans that display very:
a. High contrast
b. High brightness
c. Low brightness
d. Low contrast
d. Low contrast
Which operation forms the basis for CT reconstruction:
a. Filtered-back projection
b. Convolution
c. Fourier transform
d. Lambert-Beer Law
c. Fourier transform
The mathematical unit that describes shades of gray on a CT image is called:
a. The window level
b. A voxel unit
c. The window width
d. A Hounsfield unit
d. A Hounsfield unit
Spatial resolution can be increased by using (1) large-size detectors (2) a smaller pixel size (3) thinner slice thickness:
a. 1 and 3
b. 1 and 2
c. 2 and 3
d. 1, 2 and 3
c. 2 and 3
Modern CT scanners rely on _____ to process acquired data:
a. Microcomputers
b. Mainframe computers
c. Supercomputers
d. Minicomputers
d. Minicomputers
In multidetector CT scanning, which of the following determines slice thickness:
a. Prepatient collimators
b. Image reconstruction parameters
c. Detector type
d. Postpatient collimators
b. Image reconstruction parameters
If extravasation occurs, contrast can be dissipated by reducing its viscosity. This can be accomplished by applying a:
a. Cold pack
b. Hot pack
c. Sterile bandage
d. Peripherally inserted central catheter (PICC) line
b. Hot pack
When image data is acquired by a CT scanner, it goes through a process known as:
a. Photon flux
b. Digitization
c. Convolution
d. Quantization
d. Quantization
50 millisievert (mSv) is equal to:
a. 15 rem
b. 5 rem
c. 100 Gy
d. 50 Gy
b. 5 rem
Compared with volume acquisition, axial acquisition results in:
a. Increased noise
b. Thinner slices
c. Lower partial volume averaging
d. Better high contrast resolution
c. Lower partial volume averaging
Spiral-helical CT scanning is based on:
a. Sequential data acquisition
b. Volume data acquisition
c. Slip ring technology
d. B and C are correct
d. B and C are correct
As the display field of view increases, the resulting radiation dose to the patient:
a. Is not affected
b. Decreases
c. Increases
a. Is not affected
Which of the following CT numbers represents water:
a. +1,000
b. 0
c. +3,000
d. -1,000
b. 0
Which of the following sources of radiation were used in Hounsfield’s first primitive CT scanner:
a. Radon
b. X-ray
c. Americium
d. Radium
c. Americium
Scintillation detectors are associated with _____ patient dose and _____ image noise:
a. Higher; increased
b. Higher; reduced
c. Lower; increased
d. Lower; reduced
d. Lower; reduced
Partial volume averaging can be improved by using:
a. A larger DFOV
b. Smaller pixel size
c. Thinner slice thickness
d. A smaller SFOV
c. Thinner slice thickness
When using a gonadal shield for a CT exam, the shield should be:
a. It is not necessary to use gonadal shielding for CT scans
b. Wrapped 360 degrees around the patient
c. Placed anteriorly (on top of the pelvis)
d. Placed posteriorly (underneath the pelvis)
b. Wrapped 360 degrees around the patient
Which of the following terms is most closely associated with image reconstruction immediately following a scan:
a. Filtered backprojection
b. Interleaved sampling
c. Longitudinal interpolation
d. Multiplanar postprocessing
a. Filtered backprojection
As post-patient collimation decreases, slice thickness:
a. Increases
b. Decreases
c. Remains the patient
b. Decreases
Fourth generation scanners employed detectors that were:
a. Curved/rotating
b. Linear/nonrotating
c. Linear/rotating
d. Curved/nonrotating
d. Curved/nonrotating
Large array parallel processors are responsible for:
a. Hardening of the x-ray beam
b. Assessing faulty detector arrays
c. Executing several tasks sequentially
d. Performing numerous tasks simultaneously
d. Performing numerous tasks simultaneously
Auto milliamperage is generally used during the acquisition of:
a. A topogram
b. Interactive data
c. A region of interest
d. A standard convolution algorithm
a. A topogram
When manipulating an image using the zoom tool, the resolution:
a. Increases
b. Stays the same
c. Decreases
c. Decreases
Increased pitch results in:
a. Increased partial volume averaging
b. Increased spatial resolution
c. Ring artifacts
d. Increased image contrast
a. Increased partial volume averaging
The trigger threshold for an abdomen/pelvis CTA is _____ HU:
a. 75 to 100
b. 125 to 150
c. 50 to 75
d. 0 to 50
b. 125 to 150
Generators are often times located within the gantry. These types of generators are typically:
a. Medium frequency
b. High frequency
c. Full wave/three-phase
d. Multiwave/two-phase
b. High frequency
Which of the following types of scanners used water bags:
a. Water bags have never been used with CT scanning
b. First and second generation
c. First generation only
d. First, second, and third generation
c. First generation only
Which of the following artifacts is a result of faulty detector elements:
a. Ring artifacts
b. Streaking
c. Aliasing artifacts
d. Partial volume averaging
a. Ring artifacts
Which of the following terms refers to the automatic removal of artifacts that occur in anatomy of various densities:
a. Filtered backprojection
b. Z-axis filtering
c. Backprojection
d. Interleaved sampling
a. Filtered backprojection
A CT tube anode angle of _____ degrees would result in the smallest effective focal spot size:
a. 15
b. 18
c. 8
d. 12
c. 8
Which of the following tests determines the uniformity of CT numbers throughout the image:
a. CT number flatness
b. Low-contrast resolution
c. High-contrast resolution
d. Standard deviation of CT numbers in water
a. CT number flatness
For postprocessed 3D images of a chest CT angiogram (CTA), which pitch would provide images with the highest quality:
a. 1.0
b. 1.2
c. 1.7
d. 1.35
a. 1.0
As pitch increases, the z-gap ____ and image quality _____:
a. Decreases; is unaffected
b. Increases; decreases
c. Increases; increases
d. Decreases; increases
b. Increases; decreases
A 16-slice helical/spiral scanner produces ____ images from a single slice of scan data:
a. 64
b. 32
c. 16
d. 8
c. 16
Image noise can be reduced by:
a. Increasing mAs
b. Decreasing slice thickness
c. Decreasing pixel size
d. B and C are correct
a. Increasing mAs
The half-scan algorithm technique is used to improve
a. Temporal resolution
b. Uniformity
c. Linearity
d. Spatial resolution
a. Temporal resolution
The Z-axis refers to the ________ plane:
a. Coronal
b. Axial
c. Sagittal
d. Transverse
b. Axial
For a routine abdomen/pelvis CT scan, the slices thickness should be ______ mm and the slice interval should be _____ mm:
a. 3; 5
b. 5; 5
c. 10; 5
d. 5; 10
b. 5; 5
When performing a CT scan of the neck, which pitch would result in the highest patient dose:
a. 0.7
b. 1.0
c. 1.2
d. 1.7
a. 0.7
Which window width (WW)/window level (WL) would be appropriate to display the lungs and air-filled spaces on a routine chest CT scan:
a. WW 400; WL 40
b. WW 1500; WL -600
c. WW 1500; WL 600
d. WW 40; WL 600
b. WW 1500; WL -600
For a head CT exam, a scan field of view (SFOV) of _____ and a display field of view (DFOV) of ____ are recommended:
a. 10cm ; 25cm
b. 25mm ; 25cm
c. 25cm ; 25cm
d. 25mm ; 25mm
c. 25cm ; 25cm
The scan field of view (SFOV) is determined by the:
a. pitch
b. prepatient collimators (not it)
c. postpatient collimators
d. CT technologist before the scan begins
d. CT technologist before the scan begins
Images acquired in cine mode require overlapping thin data sets. This results in _____ spatial resolution and ____ patient dose
a. increased; increased
b. increased; decreased
c. decreased; increased
d. decreased; decreased
a. increased; increased
Which of the following tests determines the ability of the patient table to return to its original position after the scan:
a. CT table indexing
b. CT table backlash
c. localization device accuracy
d. slice width
b. CT table backlash
For a CT scan of the neck, the recommended DFOV is ___cm and the SFOV is ___cm.
a. 50; 22-25
b. 50;50
c. 22-25; 50
d. 22-25; 22-25
c. 22-25; 50
Which of the following terms is associated with seventh generation spiral-helical technology:
a. multisection scanner
b. multidetector scanner
c. multiple detector array scanner
d. All choices are correct
d. All choices are correct
Which of the following is not an example of a kernel:
a. edge enhancement filter
b. smoothing filter
c. standard convolution algorithm
d. interactive algorithm
d. interactive algorithm
Which of the following would most likely be associated with a CT scan of the lung:
a. WW 80; WL 40
b. WW 1600; WL 300
c. WW 80; WL -400
d. WW 1500; WL -400
d. WW 1500; WL -400
When scanning a head with IV contrast, a scan delay of ___ is recommended:
a. 30 seconds to 1 minute
b. 1 to 2 minutes
c. 3 to 4 minutes
d. 10 minutes
c. 3 to 4 minutes
Which of the following medications most likely would be used to treat urticaria (hives):
a. metformin
b. dopamine
c. naloxone
d. diphenhydramine
d. diphenhydramine
What does longitudinal interpolation with z-axis filtering calculate:
a. interslice distance
b. pitch
c. filtered backprojection
d. scan time
a. interslice distance
Interpolation is directly affected by:
a. pitch
b. focal spot size
c. filtered backprojection
d. A and B are correct
a. pitch
Which of the following techniques would be used for a patient who has trouble holding his or her breath or has an irregular heart beat:
a. half-scan algorithm
b. prospective gating
c. smoothing
d. retrospective gating
d. retrospective gating
The typical kilovolt peak (kVp) range used for CT scans is:
a. 90-100
b. 100-120
c. 100-140
d. 120-160
c. 100-140
Which of the following International System of Units (SI) measurements is associated with monitoring radiology staff:
a. coloumb/kilogram (C/kg)
b. becquerel (Bq)
c. gray (Gy)
d. sievert (Sv)
d. sievert (Sv)
One advantage of reformatting is that image detail is increased:
a. True
b. False
b. False
The recommended bone algorithm WW/WL for a routine thoracic/lumbar spine CT is:
a. WW 2000; WL 200
b. WW 2000; WL 100
c. WW 200; WL 2000
d. WW 400; WL 50
a. WW 2000; WL 200
Which of the following results in higher resolution:
a. thick collimation
b. thin collimation
c. Collimation does not affect resolution
b. thin collimation
The typical modern CT scanner generator converts:
a. low-voltage AC to high-voltage DC
b. low-voltage DC to high-voltage DC
c. high-voltage DC to low-voltage DC
d. low-voltage DC to high-voltage DC
a. low-voltage AC to high-voltage DC
The trigger threshold for a pulmonary embolus CT exam is _____ Hounsfield units (HU):
a. 0 to 50
b. 50 to 90
c. 90 to 100
d. 100 to 200
c. 90 to 100
When performing a routine CT scan of the neck, which pitch would result in the highest resolution:
a. 0.7
b. 1.0
c. 1.2
d. 1.7
a. 0.7
Detectors measure the transmitted x-ray beam. The beam that has been attenuated or changed after interacting with the tissues of the patient is called the ______ beam
a. Primary
b. Incoming
c. Secondary
d. Dominant
c. Secondary
Beam-shaping filters are designed to:
a. Remove higher-energy photons from the beam
b. Change the spatial distribution of the beam
c. Decrease subject contrast
d. Restrict the path of photons coming from the x-ray tube
a. Remove higher-energy photons from the beam
Gating is a technique that can effectively reduce patient dose by as much as ______%
a. 100
b. 90
c. 80
d. 70
d. 70%
In helical/spiral scanning, overlapping results in _____ patient dose and ______ spatial resolution:
a. Increased; increased
b. Increased; decreased
c. Decreased; increased
d. Decreased; decreased
a. Increased; increased
What is the effect of increased image noise:
a. Increased contrast resolution
b. Decreased contrast resolution
c. Improved image quality
d. A and C are correct
b. Decreased contrast resolution
Which of the following terms refers to the center of the scan field:
a. Z axis
b. Target
c. Epicenter
d. Isocenter
d. Isocenter
Partial volume averaging occurs when
a. Similar tissue types share the same voxel
b. Cardiac studies are performed
c. Metal objects are present within the patient or the patient’s clothing
d. Detector elements fail
a. Similar tissue types share the same voxel
Which of the following medications reverses the effects of narcotics:
a. Atropine sulfate
b. Diphenhydramine
c. Dopamine
d. Naloxone
d. Naloxone
The ability of the CT scanner to calculate image data from multiple, overlapping acquisition data sets is called _______ sampling
a. Interpretive and interleaved
b. Interpretive and interlaced
c. Interleaved and interlaced
d. Interpretive, interleaved and interlaced
c. Interleaved and interlaced
Filament size is directly related to
a. Slice thickness and mA selected
b. Slice thickness and spatial resolution
c. mA selected and spatial resolution
d. slice thickness, mA selected and spatial resolution
d. slice thickness, mA selected and spatial resolution
Nutating refers to the process of
a. Tilting the detector ring
b. Tilting the x-ray tube
c. Tilting the gantry
d. Translation
a. Tilting the detector ring
Which of the following techniques reduces edge gradient artifacts
a. Scanning with thinner slices
b. Decreasing data sampling rates
c. Scanning with thicker slices
d. Using detectors with large apertures
a. Scanning with thinner slices
Which of the following is associated with a 3D representation of tissue volume
a. Matrix
b. Pixel
c. Voxel
d. Sampling
c. Voxel
To assure quality images for postprocessed reformats of the ankle joint, a _____-mm scan thickness and _____-mm slice interval is appropriate
a. 0.75; 0.04
b. 0.75; 0.4
c. 7.5; 4
d. 4; 4
b. 0.75; 0.4
Which of the following is not a postprocessing technique:
a. Image smoothing
b. Maximum intensity projection (MIP)
c. Volume rendering
d. Longitudinal interpolation
d. Longitudinal interpolation
The recommended slice thickness for a routine CT scan of the neck is ______ mm
a. 1
b. 1.5 to 2.5
c. 2.5 to 3
d. 5
c. 2.5 to 3
Compared with traditional single-slice axial scanners, helical/spiral scanners acquire images at ______ rate
a. A faster
b. A slower
c. The same
a. A faster
Dose modulation is most closely related to which of the following terms
a. Automatic mA and convolution
b. Automatic mA and automatic exposure control
c. Convolution and automatic exposure control
d. Automatic mA, convolution and automatic exposure control
b. Automatic mA and automatic exposure control
A standard window width (WW) of ______ is used to demonstrate brain tissue
a. 20-40
b. 60-80
c. 80-100
d. 100-200
c. 80-100
For CT scanning, as mAs increases, patient dose _____ and image noise _______
a. Decreases; decreases
b. Increases; increases
c. Increases; decreases
d. Decreases; increases
c. Increases; decreases
When scanning the head/brain, which radiographic baseline should be oriented parallel to the axial scan plane
a. Mentomeatal line (MML)
b. Intraorbitomeatal line (IOML)
c. Orbitomeatal line (OML)
d. Ancanthiomeatal line (AML)
c. Orbitomeatal line (OML)
Which generation of CT scanners was the first to use a curved array of rotating detectors
a. Second
b. Third
c. Fourth
d. Fifth
b. Third
A topogram image for a routine abdomen CT should include the ______ to the ________
a. Jugular notch; pubic symphysis
b. Jugular notch; iliac crests
c. Axilla; iliac crests
d. Xiphoid tip; iliac crests
c. Axilla; iliac crests
The window width (WW) determines the:
a. Image density
b. Image contrast
c. Voxel depth
d. Voxel width
b. Image contrast
CT fluoroscopy is especially useful for
a. VR colonography
b. Biopsies
c. Xenon studies
d. Vessel tracking
b. Biopsies
A log amplifier calculates the amount of attenuation that occurs during data acquisition
a. True
b. False
a. True
For a routine chest CT, the recommended pitch is
a. 0.5 to 0.8
b. 0.8 to 1.0
c. 0.8 to 1.35
d. 0.5 to 1.35
c. 0.8 to 1.35
For a routine CT scan of the neck, the gantry should
a. Be angled perpendicular to the OML
b. Not be angled
c. Be angled to coincide with the OML
d. Be angled to coincide with the MML
b. Not be angled
Second generation scanning employed:
a. A pencil beam/a single detector
b. A fan beam/multidetectors
c. More indexing (compared with first generation scanners)
d. B and C are correct
b. A fan beam/multidetectors
Image reconstruction occurs only after a scan is completed
a. True
b. False
a. True
For a routine chest CT scan, the recommended SFOV is ______ cm
a. 25
b. 50
c. 75
d. 100
b. 50cm
The term “misregistration” refers to
a. Backprojection reconstruction
b. Noise
c. Incorrect image reconstruction
d. Convolution
c. Incorrect image reconstruction
Which of the following quality control (QC) tests should be performed daily
a. CT number calibration and CT couch indexing
b. CT number calibration and standard deviation of the CT number in water
c. CT couch indexing and standard deviation of the CT number in water
d. CT number calibration, CT couch indexing and standard deviation of the CT number in water
b. CT number calibration and standard deviation of the CT number in water
A topogram for a CT scan of the neck must include the _____ to the ______
a. Vertex of the skull; axilla
b. Vertex of the skull; mid-chest
c. OML; mandibular rami
d. OML; axilla
b. Vertex of the skull; mid-chest
What is the linearity phantom used to test
a. Spatial resolution
b. Assignment of CT numbers to known linear attenuation coefficients
c. Contrast resolution
d. Temporal resolution
b. Assignment of CT numbers to known linear attenuation coefficients
Absorption efficiency refers to how efficiently x-ray photons are captured by the detectors
a. True
b. False
a. True
Which of the following types of beam geometry results in increased scatter
a. Pencil beam
b. Cone beam
c. Fan beam
d. Parallel beam
b. Cone beam
Ghosting refers to _____ artifacts
a. Motion
b. Cupping
c. Ring
d. Static
a. Motion
Which of the following determines the uniformity of CT numbers throughout the image
a. High-contrast resolution
b. Low-contrast resolution
c. Standard deviation of CT numbers in water
d. CT number flatness
d. CT number flatness
Which of the following postprocessing techniques is referred to as 4-D reconstruction
a. Volume rendering
b. Shaded surface rendering
c. Curved multiplanar reconstruction
d. Edge enhancement
a. Volume rendering
All power to the gantry of a spiral-helical CT scanner is conveyed via
a. High-tension cables
b. Rotating wire brushes
c. Photon flux
d. Slip rings
d. Slip rings
Coronal and sagittal reconstructions of the lumbar spine require a slice thickness of ____ mm
a. 10
b. 5
c. 3
d. 1-2
d. 1-2
Modern CT scanners are able to differentiate tissue with different density differences of less than ____%
a. 1.0
b. 0.5
c. 0.1
d. .15
b. 0.5
When performing a routine chest CT scan, the scanner should be zeroed with the laser light at the
a. Jugular notch
b. Xiphoid tip
c. EAM
d. Top of the shoulders
d. Top of the shoulders
