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Mobile Radiography
Fluoroscopy
Tomography
MRI
MISC.
100
Why are mobile exams often more difficult to complete than those exams done in the radiography department?
What is...there are so many additional variables... *Patient condition *imaginative equipment manipulation *Non routine projections *Room size limitations *Presence of additional critical equipment
100
Compared to "static" diagnostic radiography, what is fluoroscopy considered as because of it's need to provide active diagnosis during an exam?
What is...Dynamic
100
During an exposure the x-ray tube and image receptor move in opposite directions around this stationary pivot point.
What is...Fulcrum..... The area of interest (kidney) is placed at the fulcrum, it does not move during the exposure like the tube and IR, and thus is the area of image sharpness.
100
What is the source of magnetic fields within the body that are used during MRI?
What is...Hydrogen
100
This automatically maintains satisfactory fluoroscopic image density and contrast.
What is...Automatic brightness control (ABC),Automatic dose control (ADC), and Automatice brightness stabilization (ABS)....... They maintain image brightness by automatically adjusting the exposure factors as necessary according to patient/subject density and contrast.
200
What is the ideal patient and tube position that will BEST demonstrate air-fluid levels?
What is....Patient upright and horizontal beam
200
If diagnostic x-ray tubes operate at 50-1,200 mA. At what mA range are fluoroscopic x-ray tubes designed to operate?
What is...0.5-5.0 mA.... Because they operate for longer periods of time.
200
This describes the total distance the tube travels.
What is...Tomographic Amplitude..... The tube does NOT have to be engaged in an exposure for the entire tomographic angle.
200
The heart of an MRI system.
What is...The Magnet.... The most commonly utilized field strength is 1.5 tesla.
200
This is a measurement of the increase in image intensity achieved by an image intensification tube and is determined by both minification gain and flux gain.
What is....Total brightness Gain
300
This is the primary cause of repeats during mobile radiography
What is...Failure to measure distance.
300
The fluoroscopy x-ray tube must be fixed to prevent an SOD of less than ______inches.
What is...15"
300
What does exposure amplitude, distance from the fulcrum, distance from the image receptor, and orientation of tube motion all affect?
What is...Blur...... Increase exposure amplitude = Increase in Blur.... Increase distance from fulcrum = Increase in Blur.... Increase distance from IR = Increase in Blur.... As tube becomes perpendicular = Increase in Blur
300
This is the most common MR contrast agent.
What is....Gadolinium......Gadolinium-based contrast agents (GBCAs)
300
This part of the image intensification tube absorbs light photons and emits electrons.
What is...Photocathode..... Which is in direct contact with the input screen to prevent divergence of the light beam.
400
Angling the CR off-center to a focused grid by as little as 5% can result in sufficient grid cutoff. List two of the four grid characteristics that will permit a wide exposure and centering latitude.
What is...*Lower grid ratio (6:1 or 8:1 versus 12:1 or 16:1), *higher frequency grid (178-200 lpi), *short dimension grid, and *wide focal range grids (40"-72").
400
The portion of the image intensification tube that absorbs the x-ray photons and emits light photons.
What is...Input fluorescent screen
400
This is the width of the focal plane and is controlled by the exposure angle.
What is..Section thickness... Inversely proportional to exposure angle/amp. As exposure angle/amplitude increases, section thickness decreases.
400
Most widely used technique for MR image reconstruction
What is...fast Fourier transform (FFT)
400
This deals only with the "gain" accomplished by the electron-to-light conversion at the output screen of the image intensification tube.
What is..Flux gain..... Flux gain is the measurement of the increase in light photons due to the conversion efficiency of the output screen.
500
The SID must be within what percent to avoid producing a significant exposure difference?
What is...15%... A 72" chest must be exposed between 61" and 83" to produce an optimal exposure when using 72" exposure factors.
500
This occurs as a result of the same number of electrons that were produced at the large input screen being compressed into the area of the small output screen.
What is...Minification gain..... Most II tubes have input screens of 6" or 9" with 12" available for special applications..... The II output screens usually have a diameter of 1"
500
This requires specialized equipment developed to permit slit scan radiography of the curved surfaces of the face and head.
What is...Panoramic Tomography.... Other similar terms: pantomography, orthopantomography, and panoramic tomography
500
Magnet resistance is controlled by magnet temperature, therefore the electromagnet is submerged into this special cryogenic liquid.
What is...Helium (He)..... Liquid helium is 4 Kelvin (K) or -452 degrees Fahrenheit
500
This is also called digital radiographic tomography because the CR images are manipulated through post-acquisition algorithms to simulate tomographic exposures.
What is...Digital Tomosynthesis..... Primary use of tomosynthesis is in breast imaging, and used in addition to mammography.