Ch. 8 Flashcards
The component of the radiographic system that produces radiation is the:
What is it made of?
- x ray tube
- made of pyrex glass & encased in a sturdy, lead lined metal housing with large high voltage electrical cables attached at each end
The selection of radiographic exposure factors such as mAs and kVp is performed at the operator:
Control Console
The quality of electrons for x ray exposure is determined by the mAs. This is calculated by:
Multiplying the milliamperage by the exposure time
The primary components of the x ray tube; important to x ray production are the:
Anode & Cathode
True digital image receptors are referred to as:
Flat Panel Detectors
All of the following are typical features of radiographic tables except:
A) they have motorized, variable height adjustment
B) they permit four way floating tabletop mobility
C) the tabletop materials offer high attenuation to lower patient dose
D) they have electric or cos on table top monitors
C) The tabletop materials offer high attenuation to lower patient dose
Component that supports and permits the x ray tube to be moved in different directions
Tube stand or overhead tube crane
In a fluoroscopic system, the surface or face of the fluoroscopic detector is considered the:
Primary Barrier
Anode
Positive electrode of the x ray tube
Cathode
Negative electrode of the x ray tube
What is diagnostic efficacy?
Accuracy of diagnostic information on a medical image
Kilovoltage Peak is ____
Speed & Penetration
- As kVp increases so does penetration
- correct kVp can vary based on patients thickness, body part, and examination type
Milliampere- Seconds
Indicates the amount of current supplied to the x ray tube
Thermionic Emission
as electrical current passes through the filament wire it’s temperature increases to the point of “boiling off” electrons
When are manual exposure typically used?
Tabletop Procedures
X Ray tube systems come in two designs, what are they?
Flour mounted tube stands & ceiling-suspended OTC’s
Definition of tube angulation?
Pivoting the tube at the point where it is attached to its support, measure and displayed in degrees
ALARA
as low as reasonably achievable
All radiation by the receptor is referred as _____
Remnant Radiation ( Remanence )
The image receptor is considered a _____ to the x ray beam, and fluoroscopic exposures are allowed only when the fluoroscopic x ray tube and image receptor are locked in place and centered.
Primary Barrier
Manipulation of medical images after they have been acquired through x ray exposure in order to improve image quality and diagnostic yield is ______
Post-processing
Undesirable image quality characteristics that shows image graininess and a loss in visual acuity; most often the result of underexposure to the receptor
Quantum Mottle
What method is used to create real-time images for the study of the dynamic action of the human body?
Fluoroscopy
X ray system basic design features include…… (6)
- x ray tube & support system
- collimator assembly
- x ray table
- x ray generator
- control console
- upright image receptor holding device
What is the cathode filament typical made of?
Tightly wound tungsten wire helix
Radiolucent
Material that easily transmits x ray energy with very little absorption
Radiopaque
Material that absorbs x ray energy, predominantly through the photoelectric effect
The power of an x ray system is rated in kilowatts and expressed numerically typically ranging from _____
30 to 100 kW
All of the following are the of fluoroscopy EXCEPT:
A) The lead protective apron attached to the fluoroscopic carriage is of little value in reducing operator dose
B) It permits “real life” imaging dynamic patient functions
C) Modern day fluoroscopy systems record images electronically rather than using cassettes
D) Dose reduction features such as late image hold, pulsed fluoroscopy, & electronic shuttering are essential
The lead protective apron attached to the fluoroscopic carriage is of little value in reducing operator dose
Inadequate mAs for an exposure can result in digital image quality that demonstrates graininess or…….
Guantum Mottle
What is; two exposures to be taken of a patients anatomy?
One at a very low kVp and one at a higher kVp.
The lower kVp exposure will allow better visualization of _____ and the higher kVp exposure penetrates dense patient anatomy more uniformly and demonstrates _______
- Dual Energy Subtraction Radiography
- Calcification
- Soft Tissue Structures
Mobile systems do not have a fixed control booth so what is the exposure switch attached to in order to maximize distance from the patient during the exposure? What is the length?
Coiled Cord ; 6 ft
CT scanners acquire images in what plane? How many images?
Transverse and hundreds
What position are patients in for a CT scan?
Laying down, Supine
trendelenburg position
Lying down head lower than the feet
The CT _____ encloses all of the x-ray generating equipment needed to produce a CT image and is the most visible feature to patients.
Gantry
What technology assesses bone health and bone material density? What is the medical condition called in women that typically need these scans?
- Dual Emission X Ray Absorptiometry (DXA)
- Osteoporosis
Mammography is breast imaging. Breast compression is an essential feature of mammography in order to create a more ____ tissue thickness, and press breast tissue structures closer to the image receptor to minimize the ______
- Homogenous
- Object image distance
What creates geometric magnification in mammography?
Increased OID , Lower kVp
There are three Pacific areas of certification in medical sonogram list them :
1) cardiac
2) obstetrics/ gynecology
3) General abdomen
Ultrasound frequencies can range from ____ to ____
1 to 20 megahertz
Ultrasound is extremely good at traveling through ____ filled tissues.
Fluid ( Cysts or Urinary Bladder )
What are the four modes of sonography??
A- mode
B- mode
M- mode
Doppler
Doppler scanning is used to assess_____ flow and vessels and uses the principle of the Doppler effect with sound waves.
Blood
What is the functional piece of equipment used by the sonographer?
Transducer
A key distinction with MRI when compared to x-ray is that with MRI the____ is the source of the signal used to create an image.
With x-ray, the ____ is the source and it relies upon the process of differential absorption as x-ray engines are transmitted through tissues and detected.
- Patient
- X Ray Tube
What are magnetic fields strength expressed in?
Units of Tesla (T)
Radionuclide imaging is often referred to as _____
Nuclear medicine 
Many medical imaging studies are considered structural studies of the anatomy; nuclear studies are generally regarded as _____ examinations.
Perfusion
What tissues are more sensitive to radiation damage?
Tissues that are rapidly dividing & poorly specialized
Medical oncology focuses on the use of toxic, ________
Radiation oncology centers around the use of _____
- Chemotherapeutic Medicines (chemo therapy)
- Radiation Energies (radiation therapy for cancer)
When using photostimulable phosphor technology (PSP); The x ray exposure is contained in _____
“electron traps” in the phosphor layer
In computer radiography, the photostimulable phosphor plate technology uses which materials as an active ingredient?
Barium Fluorohalide
Electrical cords that attach a DR detector to a portable are called tethers.
True or False
True
If the mAs used for an exam was 24 and the mA station was 500, then what is the time?
.048 seconds
The component that controls the size and shape of the x ray exposure field is the:
Collimator Assembly
All of the following are features of radiographic tables except:
A) motorized, variable height adjustment
B) four-way floating table top mobility
C) tabletop materials that are high and x-ray attenuation
D) electric locks on table top motions
C) tabletop materials that are high and x-ray attenuation
Unnecessarily prolonged anode prepping or repeated prepping can result in
damage or shortened tube life
Medical images that are displayed on a monitor are referred to as a:
Soft Copy
What mAs is most diagnostic radiography done at? Fluoro?
- 50-400 mA
- 0.5-5.0 mA
Postprocessing functions can include (5):
Image Reversal
Image Annotation
Spatial Filtering ( Edge Enhancement )
Magnification
Windowing of Brightness and Contrast
What holds the last image flouro image and allows viewing without additional exposure to the patient
Last image hold
The amount of clinically useful information on a medical image
Diagnostic Yield
