Quiz: Medical CT Registry Review Questions!
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The CT registry review quiz is intended for technologists who need an effective way to prepare and pass the CT certification exam. Computed tomography (CT) is described as an imaging procedure that uses special x-ray equipment to create detailed scans of areas inside the body. Test your understanding of this concept by taking the quiz below and acing that upcoming final exam!
- 1.
- A.
IV contrast material is better visualized.
- B.
Streak artifacts are reduced or eliminated.
- C.
The patient is more comfortable during scanning.
- D.
The patient receives a lower radiation dose.
- 2.Which two strategies can reduce the effect of dental fillings in a sinus study?
- A.
High mA and short scan time.
- B.
Low kVp and high contrast, or bone algorithm.
- C.
Adjust the angle of the gantry and widen the window width.
- D.
Small focal spot and small display field.
- 3.Which of the following conditions may be visualized in a CT study of the brain?
- A.
Glioblastoma
- B.
Wilm's Tumor
- C.
Krukenberg Tumor
- D.
Plasmacytosis
- 4.Which of the following is affected by the slice spacing in a CT study?
- A.
Spatial Resolution
- B.
Quantum Mottle
- C.
Radiation Dose to the Patient
- D.
Signal-to-Noise Ration
- 5.What is the name of the pinecone-shaped structure of the brain the can often be seen as calcified in CT images?
- A.
Choroid Plexus
- B.
Pineal Gland
- C.
Caudate Nucleus
- D.
Middle cerebral Artery
- 6.Third generation (rotate/rotate) scanners overcame which of the following limitations?
- A.
Detector singal drift sensitivity
- B.
Translation motion
- C.
Spurious signals from moving signal wires
- D.
Cost
- 7.What helical or spiral computed tomography term is defined as the table increment in distance per mm per 360 degrees gantry rotation divided by the section thickness in mm?
- A.
Rotation
- B.
Spiral
- C.
Helix
- D.
Pitch
- 8.What determines the section thickness?
- A.
Scan arc
- B.
Filtration algorithm
- C.
Incident beam collimation
- D.
Detector alignment
- 9.What effect would an array processor failure have on image processing?
- A.
Increase image display time.
- B.
Halt analog to digital conversions.
- C.
Lengthens detector data acquisition time.
- D.
Decrease xray tube output.
- 10.What change will occur in the number of detected photons if a section thickness is changed from 5 mm to 10mm?
- A.
Decrease 50%
- B.
Decrease 25%
- C.
Increase 50%
- D.
Increase 100%
- 11.Which of the following will magnify the image?
- A.
Increase the field of view.
- B.
Decreasing field of view.
- C.
Increasing section thickness.
- D.
Decreasing section thickness.
- 12.Which of the following is convolution?
- A.
Filtered back projection
- B.
Fourier transform
- C.
Iterative filtration
- D.
3-d rendering
- 13.Which of the following determines the maximum number of shades of gray that can be displayed on the CT monitors?
- A.
Window level
- B.
Window width
- C.
Pixel size
- D.
Matrix size
- 14.Which of the following are benefits of narrower section thicknesses?
- A.
Reduced partial volume averaging and improved spatial resolution
- B.
Decreased scan time, and more anatomy covered
- 15.Which of the following is the term used to describe a voxel value that is the average of multiple tissue types contained within the voxel?
- A.
Linear attenuation coefficient.
- B.
Partial volume averaging.
- C.
Low contrast resolution.
- D.
Edge gradient averaging.
- 16.Which of the following CT numbers would appear as a gray shades when a window width of 300 and a window level of 0 are selected?
- A.
Ct numbers above +300
- B.
Ct numbers between +150 and +300
- C.
Ct numbers between +150 and -150
- D.
Ct numbers below -150
- 17.Which fo the following is the central value in a range of gray shades used to display the image?
- A.
Window width
- B.
Window level
- C.
Region of interest
- D.
Dose index
- 18.What is the most common type of film used to recore CT exams?
- A.
Single emulsion
- B.
Double emulsion
- C.
Triple emulsion
- D.
Rare earth
- 19.Which of the following increase signal to noise ration?
- A.
Increased mAs
- B.
Wider section thickness
- C.
Increased detection efficiency
- 20.What is the appropriate compensation to avoid quantum noise when performing thin section computed tomography?
- A.
Increase mAs
- B.
Decrease field of view
- C.
Increase matrix size
- D.
Decrease scan speed
- 21.Which describes the relationship between section thickness and noise?
- A.
If section thickness increases, noise increases
- B.
If section thickness increases, noise decreases
- C.
If section thickness decreases, noise decreases
- D.
If section thickness decreases, noise remains unchanged
- 22.What term is used to describe as the ability to display an image of a large object that is only slightly different in density from its surroundings?
- A.
Spatial resolution
- B.
Contrast resolution
- C.
Linearity
- D.
Clarity
- 23.Which of the following should be viewed with relatively wide window widths?
- A.
Lung and inner ear
- B.
Lung and brain
- C.
Inner ear and brain
- 24.How often should an average CT number water calibration test be performed?
- A.
Daily
- B.
Monthly
- C.
Yearly
- D.
Weekly
- 25.Which of the following accurately describes the relationship between patient dose and pitch?
- A.
If pitch increases, patient dose increases
- B.
If pitch increases, patient dose decreases
- C.
If pitch decreases, patient dose decreases
- D.
If pitch decreases, patient dose remains unchanged
- 26.Which of the following is defined as the ability to distinguish details in objects of different densities a small distance apart?
- A.
Contrast resolution
- B.
Cross field uniformity
- C.
Spatial resolution
- D.
Interpolation
- 27.
- A.
High spatial detectibilty
- B.
Low spatial detectibilty
- C.
High contrast detectibilty
- D.
Low contrast detectibilty
- 28.What is the primary type of interaction that contributes to the subject contrast in CT images?
- A.
Pair production
- B.
Photoelectric effect
- C.
Compton scattering
- D.
Linear attenuation
- 29.What type of scan geometry is responsible for producing ring artifacts?
- A.
Translate-rotate
- B.
Rotate-rotate
- C.
Rotate only
- D.
Helical / spiral
- 30.What is the cause for the "cupping" artifact?
- A.
The computer overcorrects for beam hardening
- B.
The beam encounters metal in the body
- C.
The body hardens the beam thus lowering the attenuation numbers in the center
- D.
The body hardens the beam thus increasing the attenuation numbers in the center
- 31.Which of the following can be described as bands and streaks that appear across an area due to bone and soft tissue attenuation values in the same pixel?
- A.
Tube arcing artifacts
- B.
Beam hardening artifacts
- C.
Partial volume artifacts
- D.
Full volume artifacts
- 32.Which of the following is a streak artifact oriented tangentially to a flat surface having a high spatial frequency?
- A.
Low contrast artifact
- B.
Edge gradient artifact
- C.
Equipment induced artifact
- D.
Signal artifact
- 33.What filter selection would provide the best detail for imaging of the internal auditory canals?
- A.
Smooth
- B.
Sharp
- C.
Standard
- D.
Soft
- 34.What anatomical structure forms a roof over the posterior cranial fossa and is shaped like a tent?
- A.
Tentorium cerebelli
- B.
Falx cerebri
- C.
Pontine cistern
- D.
Pia mater
- 35.Which of following results from a fracture in the temporal region of the skull with associated tearing of the middle meningeal artery?
- A.
Subdural hematoma
- B.
Epidural hematoma
- C.
Arteriovenous malformation
- D.
Subarchnoid hematoma
- 36.Where is contrast media introduced for a myelography exam of the spinal canal?
- A.
Subdural space
- B.
Epidural space
- C.
Subarachnoid space
- D.
Spinal cord
- 37.Which of the following anatomical structures would be visualized first when obtaining sagittal sections from right to left?
- A.
C-loop of the duodenum
- B.
Tail of the pancreas
- C.
Gallbladder
- D.
Right kidney
- 38.What type of drug is Demerol?
- A.
Analgesic
- B.
Antipyretic
- C.
Antianxiety agent
- D.
Local anesthetic
- 39.Which of the following describes rapid, irregular, ineffective twitches of the ventricles?
- A.
Ventricular regurgitation
- B.
Ventricular palpitations
- C.
Ventricular arrythmia
- D.
Ventricular fibrillation
- 40.Which of the following is the more toxic cation that is incorporated into the organic ionic contrast media?
- A.
Sodium
- B.
Meglumine
- C.
Iodine
- D.
Calcium
- 41.What term is used to describe the computed tomography appearance of an intracerebral hemorrhage as a result of a higher CT number of the hemorrhage as compared to normal brain tissue?
- A.
Hyperdense
- B.
Isodense
- C.
Hypodense
- D.
Mass effect
- 42.Which of the following provides optimal liver lesion detection following the introduction of contras media?
- A.
Scanning prior to the equilibrium phase
- B.
Scanning during to the equilibrium phase
- C.
Scanning after to the equilibrium phase
- 43.Which of the following is the recommended percentage of barium in a barium sulfate suspension utilized in abdominal computed tomography?
- A.
1-3%
- B.
10-20%
- C.
30%
- D.
50%
- 44.Which of the following are used in scintillation CT detectors?
- A.
Gadolinium based ceramic
- B.
Bismuth germanate
- C.
Calcium fluoride
- 45.Which of the following will have an effect on image quality?
- A.
Spatial resolution
- B.
Contrast resolution
- C.
Noise
- 46.What are the primary advantages of narrower section thicknesses?
- A.
Improved spatial resolution
- B.
Reduced partial volume averaging
- C.
Higher contrast
- 47.Which of the following geometric factors will have an effect on spatial resolution?
- A.
Focal spot size
- B.
Detector aperture width
- C.
Noise
- 48.What term describes an artifact that may appear on a low dynamic range detector system near the shoulders and hips because dense bone has too severely attenuated the xray beam?
- A.
Beam hardening
- B.
Photon starvation
- C.
Ring
- D.
Partial volume
- 49.Which of the following will help to reduce partial volume artifacts?
- A.
Scanning thinner sections
- B.
Scanning thicker sections
- C.
Scanning using a higher technique
- D.
Scanning using a lower technique
- 50.Which of the following terms defines the increase in the mean energy of a polychromatic beam as it passes through an object?
- A.
Partial volume effect
- B.
Beam hardening
- C.
Cross-field uniformity
- D.
Linearity
- 51.Which of the following is the correct order for the stages of infection?
- A.
Incubation, prodomal, active, convalescence
- B.
Convalescence, active, prodomal, incubation
- C.
Prodomal, incubation, convalescence, active
- D.
Incubation, convalescence, prodomal, active
- 52.The term used to descibe the ability of a fluid to flow is
- A.
Density
- B.
Viscosity
- C.
Osmolality
- D.
Specific gravity
- 53.A patient has a severe vagal reaction to iodinated contrast material that includes bradycardia. Initial treatment may include
- A.
Atropine
- B.
Diazapam
- C.
Rantidine hyrochloride (Zantac)
- D.
Albuterol sulfate (Proventil)
- 54.Which of the following interactions between xray and matter results in the largest amount of occupational exposure?
- A.
Characteristic effect
- B.
Compton effect
- C.
Bremsstrahlung effect
- D.
Photoelectric effect
- 55.The abdominal aorta bifurcates at the level of
- A.
T10
- B.
T12
- C.
L2
- D.
L4
- 56.After the injection of intravenous contrast material during a CT examination of the brain, which of the following anatomic areas does not enhance?
- A.
Anterior communicating artery
- B.
Choroid plexus
- C.
Posterior horn of the lateral ventricle
- D.
Dura mater
- 57.The mathematical technique that involves the estimation of an unknown value from values on either side of it its known as
- A.
Filtering
- B.
Interpolation
- C.
Convolution
- D.
Summation
- 58.When compared with conventional radiography, CT produces diagnostic images with improved
- A.
Low-contrast resolution
- B.
Spatial resolution
- C.
Minute detail
- D.
Patient dose reduction
- 59.Which of the following is not commonly used as a CT scintillation detector material?
- A.
Ceramic rare earth
- B.
Silver halide
- C.
Bismuth germinate
- D.
Cadmium tungstate
- 60.Which of the following is the primary interaction between xray photons and tissue during CT examinations?
- A.
Bremsstrahlung effect
- B.
Characteristic effect
- C.
Compton effect
- D.
Coherent scatter
- 61.Areas of a CT image that contain minimal changes in tissue density are electronically represented by
- A.
Positive CT numbers
- B.
High spatial frequencies
- C.
Negative CT numbers
- D.
Low spatial frequencies
- 62.Which of the following reconstruction methods is used by most modern CT scanners?
- A.
Back-projection
- B.
Iterative methods
- C.
Fourier tranform
- D.
Filtered back-projection
- 63.Which of the following increases the signal-to-noise ratio of a CT image?
- A.
Decreased aperature size
- B.
Decreased mAs
- C.
Increased filtration
- D.
Increased aperature size
- 64.Statistical noise appears as ___ on a CT image
- A.
Decreased contrast
- B.
Increased brightness
- C.
Concentric circles
- D.
Graininess
- 65.The term ___ describes the ability of a CT scanner to differentiate objects with minimal differences in attenuation coefficients
- A.
Spatial resolution
- B.
Contrast resolution
- C.
Linearity
- D.
Modulation
- 66.Which of the following types of contrast material may be used during a CT examination of the chest?
- A.
Diatrizoate meglumine
- B.
Barium sulfate
- C.
Iopamidol
- D.
All the above
- 67.The kidneys are located in the retroperitoneum and are bound by a band of fibrous connective tissue called
- A.
Cooper's liagment
- B.
Fascia of Cooper
- C.
Linea alba
- D.
Gerota's fascia
- 68.Which of the following algorithm types provides the greatest soft-tissue detail during a CT study of the pelvis?
- A.
High spatial frequency
- B.
Detail
- C.
Edge
- D.
Low spatial frequency
- 69.The average CT value for blood is approximately
- A.
-50 HU
- B.
0 HU
- C.
+45 HU
- D.
+100 HU
- 70.Before a CT image can be reconstructed by a computer, the transmission signal produced by the detectors must be converted into numeric information by a(n)
- A.
Kernel
- B.
Analog-to-digital converter
- C.
Array processor
- D.
Digital-to-analog converter
- 71.The dimensions of a voxel may be calculated as the product of which of the following?
- A.
Matrix size and pixel size
- B.
Pixel size and section width
- C.
DFOV and matrix size
- D.
DFOV and pixel size
- 72.Which of the following terms are commonly used to describe the ability of a CT scanner to differentiate objects with similar linear attenuation coefficients?
- A.
Spatial resolution
- B.
Contrast resolution
- C.
Spatial resolution and sensitivity
- D.
Sensitivity and contrast resolution
- 73.Which of the following section widths would cause the greatest amount of partial volume averaging?
- A.
1mm
- B.
3mm
- C.
5mm
- D.
10mm
- 74.An image that is reconstructed a second time with some change in technical factor is termed _____.
- A.
Reiterated
- B.
Post-processed
- C.
Retrospective
- D.
Reformatted
- 75.During CT angiography, images may be reconstructed using only the greastest density encountered along each ray. This type of specialized CT image is called a(n)
- A.
3 demensional model
- B.
Volume-rendered model
- C.
MIP image
- D.
Surface-rendered image
- 76.The ability of a CT scanner to image a small high-density object is controlled by ___ of the scanner
- A.
Contrast resolution
- B.
Spatial resolution
- C.
Sensitivity
- D.
Contrast resolution and sensitivity
- 77.Which of the following technical changes may increase the partial volume effect present on a spiral CT scan?
- A.
Decrease the pitch
- B.
Decrease the aperature size
- C.
Increase in matrix size
- D.
Increase in pitch
- 78.The matrix size describes which of the following?
- A.
Aperture size used during data acquistion
- B.
Number of pixels used to display an image
- C.
Relationship between the field of view and algorithm
- 79.The type of filter used at the xray tube of a CT scanner is called a
- A.
Kernel
- B.
Water bath
- C.
Bow-tie filter
- D.
Wedge filter
- 80.Which of the following would increase the noise of a CT image?
- A.
Increased mAs
- B.
Decreased aperture size
- C.
Decreased filtration
- D.
Decreased matrix size
- 81.The interaction between xray and matter that is responsible for the production of the scatter radiation absorbed by the patient and detectors is
- A.
Compton interaction
- B.
Bremsstrahlung interaction
- C.
Photoelectric effect
- D.
Characteristic interaction
- 82.The major disadvantage of the back-projection method of image reconstruction is the appearance of the
- A.
Partial volume effect
- B.
Ring artifact
- C.
Gibbs phenomenon
- D.
Star artifact
- 83.The contast resolution of a CT scanner is not related to which of the following?
- A.
Focal spot size
- B.
Section width
- C.
Reconstruction algorithm
- D.
Signal-to-noise ratio
- 84.
- A.
Increasing filtration
- B.
Decreasing collimation
- C.
Decreasing applied voltage
- D.
Increasing collimation
- 85.Which of the following is a solid-state device used to record the light flashes given off by a scintillation crystal?
- A.
Photomultiplier tube
- B.
Anode
- C.
Photodiode
- D.
Input phosphor
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