Diagnostic Imaging Flashcards
Are X rays shorter or longer in wavelength in comparison to Visible light, radio, and television signals?
Much shorter wavelengths
#11, McCurnin’s (electronic version) 10th ed. Pg 1428
What is the term for the negatively charged side of the tube that contains 1-2 filaments housed inside of the focusing cup?
Cathode
#11, McCurnin’s (electronic version) 10th ed. Pg1430
What are rotating anodes?
It is a tungsten alloy bonded to molybdenum or graphite which helps dissipate the intense heat produced by a high-powered x-ray machine.
#11, McCurnin’s (electronic version) 10th ed. Pg 1436
What is the heel effect?
The uneven distribution of x-ray photons exiting the tube. This is due to the target angle and absorption by the anode material.
#11, McCurnin’s (electronic version) 10th ed. Pg 1436
What do kVp setting effect?
The scale of contrast on a radiographic image.
#11, McCurnin’s (electronic version) 10th ed. Pg1447
What are the 5 essential components needed to create and x-ray beam?
1 IB
source of electrons, accelerating electrons, obstacle free path for electrons to travel at top speed, target for electrons to interact with, vacuum environment
McCurrin’s 10th edition pg 444
What is DICOM?
1 IB
digital imaging and commmunication in medicine - which is a universal digital format that allows images to be shared
McCurrin’s 10th edition pg 457
Density vs Contrast
1 IB
density - degree of darkness on the image
contrast - the difference of density between two areas on the image
McCurrin’s 10th edition pg 458
How long should a veterinary practice keep film radiographs for?
1 IB
3 years
McCurrin’s 10th edition pg 462
Define echogenicity
1 IB
the strength/amplitude of returning echoes
McCurrin’s 10th edition pg 474
What is the anode?
The positive side of the tube, and attracts the negative electrons
McCurrin’s 10th edition pg 445
#5
What is scatter radiation?
lower energy x-ray photons that have undergone a change in direction after interacting with structures
McCurrin’s 10th edition pg 446
#5
What does milliamperage change when taking an x-ray?
-the quality of electrons boiled off the filament in the X-ray tube, affecting the number of X-rays produced. Changing the density of the image.
McCurrin’s 10th edition pg 448
#5
When does foreshortening occur?
When a portion of the patient is lifted off the image receptor while another part is in contact with the image receptor, causeing the image to appear shorter
McCurrin’s 10th edition pg 460
#5
What is the maximum permissible dose?
0.05 Sv per year/ 5rem
McCurrin’s 10th edition pg 463
#5
What is scatter radiation?
Lower energy x-ray photons that have undergone a change of direction after interacting with the patient’s body
McCurnin’s 10th edition pg. 446
#19 JY
What is Sante’s rule?
( 2 X thickness of tissue in cm) + distance = kVp
McCurnin’s 10th edition pg 449
#19 JY
What does ALARA stand for?
As Low As Reasonably Achievable
McCurnin’s 10th edition pg 464
#19 JY
What are the 3 methods of radiation protection?
- Time
- Distance
- Shielding
McCurnin’s 10th edition pg 465
#19 JY
What are the four doppler techniques and what are they used for?
- Color Doppler- illustrates the flow and direction of blood
- Power Color Doppler- used to track flow but not direction of blood
- Pulse Wave Doppler- does well for illustrating smaller blood vessels
- Continuous Wave Doppler- useful in conditions where higher velocity blood flow is more common
McCurnin’s 10th edition pg 473
#19 JY
What is a caliper used for in radiology?
Used to measure the thickness of the anatomical area being imaged in the direction the beam will pass
SS 18
McCurnin’s 10th Edition
pg. 449
Define focal-film distance
Distance between target in the x-ray tube and the surface opf the x-ray detector
SS 18
McCurnin’s 10th Edition
pg. 450
What is the normal focal-film distance for small vs. large animal radiology?
Small animal: 90-105 cm
Large animal: 70-85 cm
SS 18
McCurnin’s 10th Edition
pg. 450
What anatomical structures benefit from the use of contrast agents during radiographs?
Gastrointestinal, urogenital, and spinal cord
SS 18
McCurnin’s 10th Edition
pg. 469
What are the two display modes for ultrasound?
B-mode: brightness mode
M-mode: motion mode
SS 18
McCurnin’s 10th Edition
pg. 472
Used to demonstrate the flow of blood or other fluids and measure their velocity
10 JM
Doppler ultrasonography
McCurnin 10th ed
pg 473
What are the front and back of x-ray cassette made of?
10 JM
Most cassettes are made of a solid plastic or light metal front. The cassette back is usually made of steel
McCurnin 10th ed pg 453
Why is it important to clip hair before ultrasounds?
Hair traps air and most of the ultrasound beam would be reflected before it enters the animal
#10 JM
McCurnin 10th ed pg 472
Slower screens are best suited for obtaining radiographs on which types of animals?
10 JM
Birds and exotics
McCurnin 10th ed pg 453
What circuit heats the filament and is known as low-votage?
Milliamperage circuit (mA)
#10 JM
McCurnin 10th ed pg 444
What is exposure time?
the time during which electrons are released from the focusing cup and accelerated across the tube for x-ray production to occur
8 PL McCurnin 10th edition pg. 449
What is kilovoltage?
kilovoltage is the quality factor that regulates energy or penetrating power of the beam
8 PL McCurnin 10th edition pg. 449
What is Radiographic detail?
the degree of sharpness that defines the edge of an anatomic structure
8 PL McCurnin 10th edition pg. 458
What is dosimetry?
measurement of personal radiation exposure. In order to provide personnel protection from over-exposure, each persons radiation exposure is measured on a personal dosimeter
8 PL McCurnin 10th edition pg. 463
What 3 views are usually required for a proper diagnosis for thoracic radiographs?
Left Lateral, Right lateral and a DV or VD view
8 PL McCurnin 10th edition pg. 467
What is a technique chart?
This provides suggested exposure factors based on the anatomic part being radiographed, the thickness of the tissue, and the position of the patient.
McCurnin 10th edition pg. 451
#6
How should unexposed film be stored?
Often stored in a film bin, this allows the film to be stored in a vertical position, which prevents film from sticking together.
McCurnin 10th edition pg. 455
#6
What is a protection officer responsible for?
Mainting dosimeters, ensuring x-ray machine is calibrated properly, and updating the technique chart.
McCurnin 10th edition pg. 464
#6
What are some aids technicians can use to help with positioning, which in turn helps lower radiation exposure?
Sandbags, porous tape, boat
McCurnin 10th edition pg. 469
#6
What do intensifying screens do?
The use of fluorescent intensifying screens dramatically decrease the amount of radiation needed.
#9 McCurnins 10th Edition pg. 453
What does screen speed refer to?
The ability to convert absorbed x-ray energy into visible light.
#9 McCurnins 10th Edition pg. 453
What does a grainy appearance in an x-ray mean?
The image is underexposed
#9 McCurnins 10th Edition pg.457
What causes magnification?
When the anatomic area is not close enough to the image receptor.
#9 McCurnins 10th Edition pg. 459
When does elongation occur?
When the x-ray beam and the structure are not centered to each other.
#9 McCurnins 10th Edition pg. 460
What type of imaging uses a strong magnetic field and cannot have any metal placed in or near?
16 RW
MRI
McCurnins 10th Edition pg. 477
Term for an area that is brighter than surroundings on an ultrasound?
16 RW
Hyperechoic
McCurnins 10th Edition pg. 474
What are the cranial and caudal columniation borders for an abdominal radiograph?
16 RW
Cranial at the xiphoid process caudally just past the greater trochanters.
McCurnins 10th Edition pg. 467
What agents are commonly used for positive contrast imaging studies?
16 RW
Barium sulfate and organic iodine agents.
McCurnins 10th Edition pg. 469
When taking images of limbs in lateral recumbecy which side should be closer to the table?
16 RW
Affected limb down on the table
McCurnins 10th Edition pg. 468
How should X-ray film be handled?
17 AG
Film should only be handled by the corners to reduce risk of damaging the image.
McCurnin 10th Ed. Pg. 455
What is the likely cause of the disappearance of thin tissues or soft tissues surrounding bone?
17 AG
Overexposure
McCurnin 10th Ed. Pg. 457
What is an Uberschwinger artifact?
17 AG
An artifact of digital processing that may be mistaken for bone lysis. Commonly caused by computer image processing issues.
McCurnin 10th Ed. Pg. 457
What is Teleradiology?
17 AG
The transmission of digital data across the internet from private practices to referral centers
McCurnin 10th Ed. Pg. 458
What are some common technical error artifacts?
17 AG
- Increased and Decreased Radiographic Density
- Distorted or Blurred Radiograph
- Miscellaneous Artifacts
McCurnin 10th Ed. Pg. 460
What is milliamperage role in taking an x-ray?
To heat the filament and to produce electrons
#2, KB, McCurnin 10th Ed. pg 445
What is the main source of radiation vet techs are exposed to?
Scatter radiation
#2, KB, McCurnin 10th Ed. pg 446
What are some differences portable units have from stationary ones?
Portable units have a smaller x-ray tube, lower mA, kVp, and exposure time capacity.
#2, KB, McCurnin 10th Ed. pg 447
Why should the surface of the cassette be kept clean?
To prevent the creation of film artifacts
#2, KB, McCurnin 10th Ed. pg 453
How should film be stored?
In a cool dry, dark place placed upright in a vertical position
#2, KB, McCurnin 10th Ed. pg 446
What tissues are most affected by ionizing radiation?
7 MJ
Skin, lymphatics, hematopoietic and leukopoietic tissues, breast, thyroid, bone, germinal epithelium or gonads
McCurinin’s 10th ed pg 462
Always use a grid between the patient and image receptor when the body part being radiographed is ____.
7 MJ
greater than 10cm thick
McCurnin’s 10th ed pg 451
What can be used to clean artifacts off of the intensifying screen ?
7 MJ
- Cleaning product by manufacturer
- 70% alcohol solution with gauze
- Distilled water with gauze
McCurnin’s 10th ed pg 453
Why is tungsten alloy the best filament to have in the cathode?
7 MJ
- High atomic number so more electrons can be produced
- High melting point so it can be heated to high temperatures without evaporating
McCurnin’s 10th ed pg 444
What two factors affect the # of photons created? How should these two factors be set to reduce patient motion blur?
7 MJ
Exposure time and mAs
highest mAs + lowest exposure time
McCurnin’s 10th ed pg 449
What is PACS?
Picture Archival Computing System; stores films on a computer, eliminating the need for film and dark rooms for developing.
McCurnin’s 10th ed pg457
#15
What can cause a Ghost Image?
-Taking an image too quickly after the previous image
-Double exposure
-Failure to erase the computed radiography from a previous study
McCurnin’s 10th ed pg457
#15
What PPE should be worn when taking radiographs?
Lead apron, gloves, and thyroid shield
#4, GG, McCurnin, Pg. 462
What do hypoechoic and hyperechoic mean/refer to?
Ultrasound terminology
-Hypoechoic= dark
-Hyperechoic= bright
McCurnin’s 10th ed pg474
#15
What is an endoscope?
A rigid or flexible tube, with a fiberoptic camera. Used to visualize internal mucosa and lumens and is not invasive.
McCurnin’s 10th ed pg475
#15
When taking radiographs of long bones what should be included in the finished radiograph?
The joint both proximal and distal of the long bone and the entire long bone.
3 LD
McCurnin’s 10th ed
pg 468
What is the proper placement of a dosimeter badge?
The outside collar of the apron or on the thyroid shield.
3 LD
McCurnin’s 10th ed
pg 464
Why is proper patient positioning crucial in radiography?
To ensure accurate anatomical representation
#4, GG, McCurnin, Pg. 466
Why are craniocaudal views of the stifle used mostly as an alternative view?
Distortion can occur to the stifle.
3 LD
McCurnin’s 10th ed
Pg 468
What is the difference between a lateral and a dorsoventral (DV) projection?
Lateral: Patient’s sides are parallel to the image receptor.
DV: Patient’s dorsal surface is toward the image receptor.
#4, GG, McCurnin, Pg. 466
When are fluoroscopic units used?
Fluoroscopic units are used for studies where a continuous image is needed (such as swallow studies).
3 LD
McCurnin’s 10th ed
pg 475
Why is fasting necessary before an abdominal ultrasound?
To improve image quality by reducing gas and food interference
#4, GG, McCurnin, Pg. 472
In what ways are MRI images superior to images from a CT?
An MRI provides better image resolution, anatomic definition, and sensitivity to tissue composition differences.
3 LD
McCurnin’s 10th ed
pg 476
Who should not be permitted in the x-ray room during exposures?
Pregnant women and people younger than 18.
14 BR
McCurnin’s 10th ed. pg 464
As it pertains to ultrasonography, what does TGC (Time-gain Compensation) refer to?
TGC is a method of compensating for the fact that echoes which bounce back from materials closer to the transducer (near field) are stronger since they traveled a shorter distance than echoes which bounced back from materials that are farther from the transducer (far field).
14 BR
McCrunin’s 10th ed. pg 473
The X-ray tube is composed of?
Negatively charged cathode and a positively charged anode that is enclosed in a vacuum environment maintained by a glass envelope.
McCurnin’s 10th ed. Pg 444 #12
What is a planking artifact?
Linear striations seen in the background of the image
Caused by plate saturation or overexposure
McCurnin’s 10th ed. pg. 457 #13
How can you produce a more uniform density radiograph?
Place the thickest part of the patient toward the cathode side of the X-ray tube.
McCurnin’s 10th ed. Pg 446 #12
What is the minimum amount of lead equivalent an apron should have to properly function as PPE during radiography?
0.5mm of lead equivalent
14 BR
McCurnin’s 10th ed. pg 466
Why do old radiographs that have been stored for 3 years or longer need to be recycled?
The silver crystals inside of them are environmental pollutants
McCurnin’s 10th ed. pg. 455 #13
What is RIS?
Radiology information system- a computer software program that allows all patient data to be made available coupled with digital image data.
McCurnin’s 10th ed. pg. 457 #13
What causes white spots?
Scratches on CR image plate
Hair, dirt or other particles trapped in the CR cassette
McCurnin’s 10th ed. pg. 457
#13
What is the ideal mm of lead equivalent for lead gloves?
1mm of lead equivalent is ideal
McCurnin’s 10th ed. pg. 464
#13
What is focal film distance?
Also known as source image distance (SID). This refers to the distance between the target
in the X-tube and the surface of the X-ray detector.
McCurnin’s 10th ed. Pg 450 #12
.
What are the contents in a cassette?
- Front padding
- Intensifying screen: Support layer, Phosphor layer
- Double-coated film: Emulsion layer, support layer, emulsion l ayer
- Intensifying screen: Phosphor layer, support layer
- Back padding
- Lead foil
McCurn:in’s 10th ed. Pg 454 #12
Definition of X-rays
X-rays are a form of electromagnetic radiation Mthat have characteristics similar to those of visible light, radio, and television signals, but with much shorter wavelengths.
McCurinin’s 10th ed. Pg 444 #12
