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Distortion
Question | Answer |
---|---|
Misrepresentation of the true size and shape of an object is the definition of? | Distortion |
What is the most important factor in controlling distortion? | OID |
What keeps distortion to a minimum? | Increased SID |
What are the 2 types of distortion that can reduce the quality of a radiograph? | Size and shape |
What occurs when the SID is increased? | Image is reduced |
What size focal spot is used when doing macroradiography? | .3mm |
When an object is placed halfway between the tube and the film, the image will be how many times larger? | 2 times |
What percentage increase is usually used for magnification radiography? | 100% |
The ratio of SID to SOD represents which of the following? | Magnification ratio |
Tube angulation will produce which type of distortion? | Elongation |
Magnification distortion can be used to an advantage for which of the following radiographic procedures? | Cerebral angiography |
Changing the shape of an object is called? | Distortion |
An x-ray tube that is designed for magnification radiography is referred to as what? | A fractional focus tube |
What factor can affect shape distortion? | X-ray tube angulation |
What advantage is there to magnifying an object? | Small objects become visible |
A misrepresentation of the shape of an object may be caused by? | An angled object, an angled x-ray tube, or an angled cassette |
What would not be used to minimize radiographic distortion? | Shortest possible exposure time |
To avoid shape distortion, what must be paid close attention to? | Part angulation |
How does magnification affect radiographic quality? | Decreases detail |
Which of the following will produce the largest image? | 40" SID, 3" OID |
If the SID is increased the same as the OID, what will the resultant radiograph show? | An increase in size distortion |
Size distortion is affected by? | Geometric factors |
What can be done to help compensate for an angled part? | Align tube, part and film |
What is the magnification factor if an object measures 4 cm, but the radiographic image is 8 cm? | 2x |
What will occur when the OID is decreased? | The image is closer to actual size |
Which of the following will produce the smallest image? | 72" SID, 2" OID |
If the SID increases, how is distortion affected? | Distortion goes down |
If the air-gap technique is used, how is distortion affected? | Distortion goes up |
If the SOD increases, how is distortion affected? | Distortion goes down |
If the phospor size increases, how is distortion affected? | It has no effect |
If the grid ratio increases, how is distortion affected? | It has no effect |
If the tube angle increases, how is distortion affected? | Distortion increases |