Other Items Flashcards
Ligaments connect
bone to bone
Rad x quality factor =
rem
Low humidity -
causes static
Polyps are best visualized on
a double contrast barium enema
Size of filament wire and angle of anode -
will have an effect on the size of the effective focal spot
You cannot clean CR plates with water because
it will discolor
Reticulation and crinkle mark -
processing error
Ethmoid is a bone of the
skull (not a facial bone)
Ileus -
small bowel obstruction
Pneumothorax -
air in the pleural space
Sternum shot at
30” SID (shallow breathing and shallow oblique 15-20 degrees)
Harrington rods are commonly used to
correct scoliosis
Penetration =
KVP
Exposure =
mAs
Parenterally -
through the skin
AEC system can only make an image darker by -
increasing the density control (adjusting the MAS will not do anything - AEC will adjust to same)
The tibia has a medial and lateral
condyle
If given a question with mA and S separately,
do the multiplication to get mAs then re look at the problem (such as comparing doses)
It takes a change of at least 30% in radiographic density
for the human eye to determine difference
Lateral rotation elbow -
shows radial head free of imposition
Characteristic -
collision
Fixed KVP
+/- 20% MAS/CM
Variable KVP
+/- 2kvp per CM
Relative Speed Formula -
mas1/mas2 = RS2/RS1 (indirect)
Grid Conversion Formula -
mas1/mas2 = gcf1/gcf2 (direct)
Density Maintenence Formula -
mas1/mas2 = D1^2/D2^2 (direct)
If given an object size, multiply this by the magnification factor
To determine ?
Magnification factor -
SID/SOD
rectification factor -
KVP x MA x S x RF (measured in heat units)
1/2 wave (self rectified) =
60 pulses, 100% ripple, 1.0 rectification factor
full wave =
120 pulses, 100% ripple, 1.0 rectification factor
3 phase 6 pulse =
360 pulses, 13-14% ripple, 1.35 rectification factor
3 phase 12 pulse =
720 pulses, 3-4% ripple, 1.35 rectification factor
high frequency =
???? pulses, 1% ripple. 1.41 rectification factor
spinning top test -
checks timer accuracy for 1/2 wave or full wave machines only
synchronous spinning top -
used for 3 phase or high frequency to test timer accuracy, measures the degree of arc
Grid used for portable can be no more than
5 or 6:1; low ratio
Grids control
contrast (and KVP does also)
grid cutoff -
Grid cutoff occurs when the x-ray tube is centered to one side of the grid rather than to the focal center line. Cutoff also occurs when the x-ray tube is angled toward one side of the gird, rather than perpendicular to its center. The same effect is encountered if the grid is tipped side to side in relation to the primary beam.
Wedge filter -
example of compensating filter
stereoradiograph -
3D image produced by 2 angled views of the same structure.
Crossed grids -
lead lines running in two directions
developer temperature -
90-95 degrees
Grid should be used when KVP Exceeds -
60 KVP
proliferation -
To grow or multiply by rapidly producing new tissue, parts, cells, or offspring; To increase or spread at a rapid rate
TLD -
lithium flouride
MAs triangle
mA | S
MA x s = mAs
To get mA divide mAs/s
To get S divide mAs/mA
Flat panel detector (DR imaging plate)
Takes the place of cassettes and readers;
3 different types: teathered (w/cord); fixed ( mounted in Bucky); wireless (muses radio signal from FPD base)
Xray emission spectrum
A serf xray frequencies emitted by a target in an X-ray tube.
Rectifier
A device that converts AC to DC
A sensitometric curve will tell you all the properties of the film in question except
Spectral sensitivity
The portion of the sensitometric curve that represents maximum optical density is
D-max
The portion of the sensitometric curve that represents minimum optical density is
Base + fog
Barium as a contrast is contraindicated when
Perforated bowel
Positive contrast media
Iodine/barium
Temporarily make the anatomy more dense than normal.
Film latitude
The margin for technique error for a given film
The margin for technique error is
Latitude
A thermoluminescent dosimeter (TLD)badge uses
Lithium fluoride
Density
Overall image blackness
Window level
Adjusts the overall optical density (aka brightness)
Raising = increase in overall density
Lowering = decrease in overall density
Window level
The exact center of the window selected, controls digital image brightness (density)
Window width
Changes the range of gray tones
Increasing = longer scale of contrast (low contrast)
Decreasing = shorter scale of contrast (high contrast)
The standard formula for calculating an air gap technique instead of a grid
10% of the SID
Edge enhancement
Computer looks for areas of common pixel signal strength across the matrix, which are then averaged and amplified to the area of interest and other tissues suppressed resulting in decreased contrast.
Potential for loss of detail/quantum mottle
The factor which has primary control of image contrast
KVP
Xray intensity
KVP and filtration
Inverse square law
The intensity of the beam is inversely proportional to the squad of the distance
I1 (d2)2 / I2 (d1)2
When the xray beam or IR is misaligned =
Elongation
When the body part is misaligned =
Foreshortening
A high signal to noise ratio indicates
Little noise
A low signal to noise ratio indicates
Lots of noise
Spatial resolution
Ability to visualize small objects
Field of view/matrix size
lp/mm
Small pixels =
Better spatial resolution
Density is referred to as ? In digital imaging
Brightness
Tendons fasten
muscle to bone
Charge coupled device
???
gastrografin versus barium
???
