Radiation Flashcards
Bergonie& tribondeau law
States all sensitivity to radiation. Exposure depends on 4 characteristics of the cell
Differentiation
Simple cells are more sensitive than high complex ones
Metabolic rate
cells that use energy rapidly are more sensitive than those that replicate slowly
MAs modifications
Deviation 🆙
Mas X 1.3
deviation ⬇️
Mas x 0.8
15% rule
Hard tissue
To increase contrast
Kvp x 0.85 , then más x2
Soft tissue
To decrease contrast
Kvp x1.15 n then MAs / 2
The study of diseases that cause abnormal changes in the structure or function of body tissues and organs is
Pathology
Which of the following is not an example if a tissue
Stomach
Neuron, muscle, skin
Bone tissue that has a honeycomb or trabecular structure is called
Cancellous tissue
Elbow joint is an example of what type of joint
Diarthrodial joint
When a limb is moved away from central part of the body this motion is called
Abduction
Technical term for a grainy or spotty image is
Quantum mottle
Milliamperage(mA) affects the
Number of photons produced per second or quantity of X-ray
The unit used to indicate the Total quantity of X-ray in an exposure
MAs
How is the energy of the X-ray beam affected when kvp is adjusted
Energy of the X-ray beam increases when KVp is increased ; vice versa
Which technique factors , if adjusted upward will increase density
mA , exposure time , MAs KVp
The primary controller of radiographic density is
MAs
A doubling in kvp will result in how many more photons being emitted
Four times more photon will be emitted
Modulation transfer function (MTF)
Is used to measure the capacity or accuracy of the digital detector to pass its spatial resolution characteristics to the final image
Signal - to noise ratio (SNR)
Describe the ability of the digital system to convert the X-ray input electric signal into a useful radiographic image
Signal refers to the useful info in the image and noise refers to the amount of info that is not useful can be caused by quantum mottle
Histogram
A graph of the minimum and maximum signals in the image
Moire pattern
This artifact occurs when grid lines are not Alignex with the laser scanning frequency of the cr reader
Light spot
Caused by dust or other foreign materials on up
Phantom or ghost images
May appear as a results dog incomplete up erasur this artifact requires troubleshooting of both the cr plate preparation system and the display system
DICOM DIGITAL IMAGING AND COMMUNICATION
is universally accepted standard for exchanging medical radiographic images.
Grid radius
The distance at which the primary X-ray beam is parallel to the focused lead strip of the grid
Erythema
Radiation burn
Outer portion of bones is a layer of hard compact bone called
Cortex
Milliamperes ( mA )
*controls radiographic density
*controls quantity of X-ray produced
*controlled by adjusting the mA
* quantity of exposure is directly proportional to mA
Exposure time (sec)
- controls radiographic density
*controls quantity of X-ray produced - controlled by adjusting the timer in the X-ray circuit
*quantity of exposure is directly proportional to exposure time
Kilovolts (kvp)
*Controls radiographic contrast
*Controls the X-ray penetration
*Controls the quantity and quality of the X-ray beam
*Increased kvp results in increased quantity of photons
* increased kvp results in increased penetration of the body Part
Source image receptor distance (SID)
Affects the density and intensity of the X-ray beam
Quantity of exposure is inversely proportional to the square of the distance
Principle factors that affect X-ray quantity
MAs, kvp, SID, and filtration
Factors that affect X-ray quality are
Kvp and filtration
The unit MAs is the primary controller of
Radiographic density
The kvp is the primary controller of the
Penetration of X-rays
Primary controller of the radiographic contrast
Kvp
Source image receptor distance
Affects the intensity of the X-ray beam and quantity of the X-rays
Density
Photographic property that refers to the overall blackness or darkness of the radiographic image
Distortion is primarily controlled by the
OID, Sid, cr angle, part position, ir position
