student quiz: Domain 6 Diagnostic imaging
Anything below what Hounsfield unit is displayed as black on CT imaging? - 750 HU 0 HU 250 HU None; black is not displayed on CT
- 750 HU
What is the typical wavelength of a medical x-ray? 0.05-0.01 mm 0.05-0.01 m 0.05-0.01 nm 0.05-0.01 dm
0.05-0.01 nm
Modern CT scanners use multislice technology and are able to acquire image slices thinner than which of the following sizes? 10 mm 1 cm 10 cm 1 mm
1 mm
Pulse wave imaging can detect velocities up to a maximum of __________ m/s. 0.5 1.0 1.4 2.2
1.4
What size of power outlet is required to run a digital dental unit? 70 kV 110 V 110 kV 8 mA
110 V
To what level of kV radiation are most lead aprons effective? 50 kV 70 kV 90 kV 125 kV
125 kV
Which of the following Hounsfield units on CT imaging appears as white? - 755 HU 120 HU 1200 HU 1260 HU
1260 HU
At what age in foals does the closure of the proximal growth plate of P2 occur? 4-22 weeks 18-30 weeks 22-38 weeks 18-38 weeks
18-30 weeks
How long does it take for barium sulfate to travel from the stomach to the colon? 30 minutes 1 hour 2 hours 3 hours
3 hours
How long should veterinary facilities maintain dosimetry reports? 5 years 20 years 30 years 1 year following separation of an employee
30 years
A computer tomography x-ray tube can rotate how many degrees? 270 degrees 180 degrees 360 degrees None, it does not rotate
360 degrees
When do fetal skeletons of small animals become visible on x-ray? 20-25 days 42-45 days 55-60 days 65-70 days
42-45 days
Which repetition time shows the T1 decay response of the tissues using MRI? 899 ms 1500 ms 546 ms 1680 ms
546 ms
MRI machines produce noise in which of the following ranges? 20-30 dB 40-50 dB 60-90 dB 100-110 dB
60-90 dB
When using computed tomography, what Hounsfield unit does blood have? -50 HU 160 HU 80 HU None of these
80 HU
In the equation Z = pV used in ultrasound, what does the letter Z represent? Density Acoustic velocity Acoustic impedance None of the above
Acoustic impedance
Before imaging the coffin bone in horses, which of the following tasks should be performed in preparation? Hoof should be trimmed to the new sole level The horseshoes need to be removed The sulcus should be packed with radiolucent material All of the above
All of the above
For digital radiography, what does the postprocessing step of image manipulation allow? Magnification Rotation Contrast adjustment All of the above
All of the above
Which of the following can occur if DNA is affected by radiation? Cell death Cell damage may be obvious, with portions of the DNA compromised Cell may display no immediate effects, but damage may have occurred internally that will affect the individual later, when mitosis occurs All of the above
All of the above
Which of the following could be considered as negative-contrast agents used in radiography? Oxygen Air Carbon dioxide All of the above
All of the above
Which of the following factors should all personnel understand about MRI machines? No loose metallic objects can be near the machine It consists of a strong magnetic field The magnet is always on Every patient/employee should be screened for safety purposes All of the above
All of the above
Which of the following is considered to be a cardinal rule for radiation protection? Distance Time Shielding All of the above
All of the above
Which parts of a patient's body are considered radioactive after they have received the radioisotope? Skin Hair Waste products All of the above
All of the above
All of the following people are allowed to view individual dosimetry reports, except: OSHA inspector Owner of the practice Only the employee exposed All team members
All team members
Which contrast is commonly used for GI studies when perforation is not suspected? Barium sulfate Meglumine diatrizoate Sodium diatrizoate Betadine
Barium sulfate
Which time frame is the most critical for limiting radiation exposure to an unborn fetus of an employee? 2nd trimester 3rd trimester Between 2 and 10 weeks gestation After 35 weeks
Between 2 and 10 weeks gestation
How does cerebrospinal fluid appear on a true T1-weighted image of MRI? White Black Different shades of gray None of the above
Black
Which of the following types of tissue absorb the most radiation? Bone Soft tissue Fat Bone, fat, and soft tissue absorb the same amount of radiation
Bone
IV contrast used with CT imaging will help to view all of the following, except: Veins Arteries Bone marrow Infection of the extremities
Bone marrow
Which of the following image receptors is used in dental imaging? Film Phosphor plates Neither Both
Both
Which particles have high linear energy transfer (LET) with low penetrability? Alpha particles Beta particles Gamma particles Both a and b
Both a and b
Which of the following correctly describes a CT image? A two-dimensional image A matrix of pixel or picture elements A three-dimensional image A matrix of voxels Both c and d Both a and b
Both c and d
If pneumonia is suspected in small animals, which of the following radiographic views should be performed? Both lateral views Dorsoventral view Both lateral views and ventrodorsal view Right lateral and dorsoventral views
Both lateral views and ventrodorsal view
Radiographs of long bones must include which of the following? The joint proximal to the long bone The joint distal to the long bone Both the joint proximal and the joint distal to the long bone The long bone only, excluding joints proximal and distal
Both the joint proximal and the joint distal to the long bone
Which of the following allows for measurements of very high blood flow velocities in ultrasound? Color Doppler PW Doppler CW Doppler Harmonics
CW Doppler
For a lateral avian view, where would the left wings and limbs be positioned? Cranially to the right wings and limbs Caudally to the right wings and limbs Lateral to the right wings and limbs Superimposed to the right wings and limbs
Caudally to the right wings and limbs
Which of the following is the best restraint to use in avian radiography? Manual restraint Physical restraint Chemical restraint None; birds should not be restrained for x-rays
Chemical restraint
Lead shutters installed in the tube head of the x-ray machine are referred to as: Filters Diaphragms Cones Collimators
Collimators
A feature of digital radiography that is related to the bit depth of each pixel and the software that accompanies the digital-imaging system is referred to as which of the following? Spatial resolution Contrast optimization Dynamic range Exposure latitude
Contrast optimization
For an avian lateral view, where should the dependent limb be placed compared to the contralateral limb? Lateral Medial Superimposed Cranial
Cranial
Digital radiography, CT, MRI, and ultrasound are stored using a universally accepted format known as? CCD DICOM MOD PACS
DICOM
Which of the following best describes the use for Doppler ultrasound? Doppler uses a motion mode that simultaneously creates a B-mode image while displaying the motion of the tissues over a two-dimensional scale Doppler is used to image the flow of blood and other liquids as well as to measure their velocity Doppler units display the different shades of gray None of the above
Doppler is used to image the flow of blood and other liquids as well as to measure their velocity
To obtain a craniocaudal view of the tibia of a small animal, that patient should be in which of the following positions? Sternal recumbency Dorsal recumbency Right lateral recumbency Left lateral recumbency
Dorsal recumbency
Meters to measure the rate of exposure is also known as: Dosimeter Fluoroscopy Collimation Shielding
Dosimeter
Which of the following is not an advantage of digital x-ray versus analog x-ray? Elimination of the darkroom Image postprocessing Elimination of damaging radiation Exposure latitude and contrast optimization
Elimination of damaging radiation
How often should x-ray equipment in a veterinarian's office be tested? Every 6 months Every year Every 2 years Only once when the equipment is installed
Every 2 years
Which of the following will cause a fogged film? Chemical spills on the screen Exposure resulting from static electricity Exposure to excessive scatter radiation Foreign materials between the film and the screen
Exposure to excessive scatter radiation
Which type of monitoring badge is the most common method of monitoring ionizing radiation? Thermoluminescent dosimeters Film badges Optically stimulated luminescence badges Ion chambers
Film badges
Which radiographic view provides the best accuracy for detecting carpal fractures in horses? Lateral view Medial oblique view Flexed lateral view Dorsopalmar view
Flexed lateral view
Which of the following imaging modalities can cause radiation burns if the unit is too close to the skin and remains in exposure mode for too long? CT MRI Fluoroscopy Ultrasound
Fluoroscopy
What causes grid lines on the entire film? Patient motion Poor film-screen contact Grid not being centered with the primary beam Focal-film distance not being in the range of the grid's focus
Focal-film distance not being in the range of the grid's focus
What occurs when the object is not parallel to the recording surface of an x-ray? Distortion Penumbra Foreshortening Fogging
Foreshortening
What does MRI require to highlight injections, tumors, or vascular disease? Gadolinium Iodine contrast Barium None of the above
Gadolinium
Which of the following is not considered a physical restraint? Tape Radiolucent Plexiglas Gloved hands Foam pads
Gloved hands
An unossified carpal or tarsal bone describes which grade level on the ossification index for newborn foals? Grade 1 Grade 2 Grade 3 Grade 4
Grade 1
Which grade level on the ossification index for newborn foals does a closed metacarpal and metatarsal physes describe? Grade 1 Grade 2 Grade 3 Grade 4
Grade 4
Which of the following locations is best for storing a dosimeter badge? In the x-ray room At home with the employee In a box on a window sill to receive natural light In a dry, cool place away from the x-ray room
In a dry, cool place away from the x-ray room
Which of the following is not a form of barium sulfate that can be administered to patients? Powder Colloid suspension Pastes Injectable
Injectable
How is gadolinium that is used in MRI excreted from the body? Liver Kidneys Lungs GI tract
Kidneys
The ability to distinguish between two objects that are adjacent to each other, yet perpendicular to the sound wave in ultrasound, is described as: Axial resolution Lateral resolution Longitudinal resolution Azimuthal resolution
Lateral resolution
A grid is a series of thin, linear strips made of alternating radiodense and radiolucent material. Of what are the radiodense strips made? Aluminum Fiber Lead Plastic
Lead
Which of the following causes a black irregular border on one end of the film? Rough handling of the film before exposure Expired film Light exposure while still in the box in advance of exposure Exposure to radiation while still in storage
Light exposure while still in the box in advance of exposure
Scatter radiation has a ____________ wavelength than the primary beam used in an x-ray. Shorter Longer Wider Thinner
Longer
Which imaging modality is superior for demonstrating the brain and spinal cord? Ultrasound MRI X-ray Fluoroscopy
MRI
Which of the following terms correctly corresponds with the phrase toward the median plane? Medial Lateral Anterior Posterior
Medial
To perform an ultrasound in the intercostal region, which transducer would be ideal? Linear probe Microconvex probe Phase array probe All of the above produce the same images
Microconvex probe
How does the adjacent bone density appear in fresh carpal chips in horses? Decreased Increased Normal
Normal
For a mediolateral view of the tarsal joint of a horse, the cassette should be placed in which position? On the lateral surface On the medial surface On the plantar surface On the plantaromedial surface
On the lateral surface
Which of the following could cause a false diagnosis of a pneumothorax on a radiograph? Underexposure of film Overexposure of film Panting Motion artifacts
Overexposure of film
Which of the following is the best technique to consider for an abdominal x-ray? Peak inspiration Peak expiration Panting Consideration of breathing techniques is not necessary for abdominal x-rays
Peak expiration
Which type of magnet consists of two slabs of magnetic material facing each other? Permanent magnets Electromagnets Resistive magnets Superconducting magnets
Permanent magnets
Which of the following correctly defines the term shims in reference to MRI? Pieces or plates of metal used to correct the magnetic field within the magnet Coils or assemblies within the magnetic bore that enable the machine to create images in any plane Devices that receive radio-wave signals from a body part that is covered or contained by them None of the above
Pieces or plates of metal used to correct the magnetic field within the magnet
What is the difference between color Doppler and power Doppler ultrasound? Color Doppler indicates velocity and power Doppler indicates direction of flow Power Doppler is sensitive to slow flow and color Doppler indicates direction of flow Power Doppler indicates direction of flow and color Doppler indicates slow flow Color Doppler indicates arteries and power Doppler indicates veins
Power Doppler is sensitive to slow flow and color Doppler indicates direction of flow
What is the amount used to express the dose equivalent that results from exposure to ionizing radiation known as? REM ALARA MPD Sv
REM
What does the MRI unit use to manipulate hydrogen atoms in and out of an excited energy state? Helium Water Radio waves Oxygen
Radio waves
In dental radiographs, periapical disease appears as a: Radiopaque area around the apex of the tooth Radiolucent area around the apex of the tooth Radiopaque area inside the tooth pulp Radiolucent area inside the tooth pulp
Radiolucent area around the apex of the tooth
Atoms that emit particles and energy to become stable are known as: Photons Radionuclides Radioactive decay Isotopes
Radionuclides
Which of the following terms is used to describe the white appearance on an x-ray? Radiolucent Radiopaque Hyperechoic Hypoechoic
Radiopaque
Which of the following does not describe an old carpal chip seen on x-ray in horses? Sharp fragment margination Decreased adjacent bone density Presence of osteoarthritis Normal or cool surrounding tissue
Sharp fragment margination
In MRI what are the various shades of gray referred to as? Densities Signal intensities Hypoechoic Hyperechoic
Signal intensities
A biarticular fracture is also known as a: Corner fracture Slab fracture Chip fracture Biarticular fractures do not exist
Slab fracture
For smaller-sized patients, which radiographic technique is preferred? Grid technique Lower mA Tabletop technique Higher kVp
Tabletop technique
Exposing a reptile to cool conditions, such as a cool metal surface, will cause what? Temporary lethargy and immobility Temporary excitement Rapid breathing Aggressiveness
Temporary lethargy and immobility
When using color-flow Doppler in ultrasound, what do the displayed red and blue colors mean? Blue colors are veins, and red colors are arteries Blue colors are arteries, and red colors are veins The colors show blood flow; blue indicates flow away, and red indicates flow toward The colors show different velocities of blood
The colors show blood flow; blue indicates flow away, and red indicates flow toward
Radiographic projections are named according to which of the following? The direction in which the central beam anatomically enters the body parts, followed by the area of exit of the x-ray beam The direction in which the central beam anatomically leaves the body parts, followed by the area of entrance of the x-ray beam The side of the patient to which the film is closest, followed by the exposed side Radiation that bounces off objects
The direction in which the central beam anatomically enters the body parts, followed by the area of exit of the x-ray beam
Decreased radiographic density with poor contrast results from which of the following? The film was overdeveloped The film was overexposed The film was underexposed The film was developed in chemicals that were too hot
The film was underexposed
Which of the following best describes the Nyquist point in ultrasound? The point at which the maximum blood velocity is reached The point of deepest penetration The point at which a drop-out signal is reached and an image is no longer produced The Nyquist point is not an ultrasound concern
The point at which the maximum blood velocity is reached
Which of the following best describes the term fulcrum? The point of interest The distortion of the resolution of anatomy above and below the region of interest A series of boxes or individual shades of information None of the above
The point of interest
What is a major safety concern with MRI machines? The amount of radiation emitted The intensity of the magnet on the patient The potential projectile effect with metallic objects within the vicinity of the machine MRI machines are extremely safe and contain no safety concerns
The potential projectile effect with metallic objects within the vicinity of the machine
When obtaining a caudocranial x-ray of the stifle joint, what should be palpated to determine the amount of rotation necessary for an exact caudocranial projection? The greater trochanter of the femur The tibial tuberosity The patella The manubrium
The tibial tuberosity
For standard radiographs of the tarsus of a horse, which of the following is the correct weight distribution? The affected limb should be suspended with no weight on it for the duration of the x-ray There should be 25% weight bearing on the affected limb There should be 50% weight bearing on the affected limb The weight should be evenly distributed on all four legs
The weight should be evenly distributed on all four legs
For what are grids used on an x-ray machine? To decrease scatter radiation and to increase the contrast on the radiograph To absorb the less penetrating x-rays as they leave the tube head To restrict the primary beam to the size of the cone used The limit the size of the primary beam to the size of the diaphragm used
To decrease scatter radiation and to increase the contrast on the radiograph
You are looking at your dental radiograph and notice that the tooth is elongated. This happened because the beam was perpendicular to the: Film Tooth Bisecting angle Wrong tooth
Tooth
What is a concern of exposure creep with the use of digital x-rays? Underexposed x-ray Unnecessary patient and personnel exposure because of ionizing radiation Excessive film blackening Exposure creep is only an issue in analog x-rays
Unnecessary patient and personnel exposure because of ionizing radiation
Dental film should be placed in the mouth with the dimple facing: Up and pointing rostrally Up and pointing caudally Down and pointing rostrally Down and pointing caudally
Up and pointing rostrally
A deformity in which the interior angle of the joint, viewed frontally, is greater than 180 degrees is known as what? Axial rotation Windswept Valgus deformity Varus deformity
Valgus deformity
A deformity, in which the interior angle of the joint, viewed frontally, is <180 degrees, is known as what? Axial rotation Windswept Valgus deformity Varus deformity
Varus deformity
Before taking a radiograph of a patient, what is the proper way to obtain a measurement of the area of interest? With the patient standing When the patient is in the position in which it is to be x-rayed When the thinnest part is targeted With the patient lying in the dorsal recumbent position
When the patient is in the position in which it is to be x-rayed
The amount of radioisotope used for each examination in a nuclear medicine study is measured in which of the following units? kV mAS mCi MHz
mCi
Radiographs of joints must include which of the following? The bones proximal to the joint The bones distal to the joint Only the joint needs to be imaged, excluding any surrounding bones {1/3} of the bones proximal and distal to the joint
{1/3} of the bones proximal and distal to the joint
