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Champa Ch 1
Radiology
| Principles of Radiographic Exp | Answer |
|---|---|
| Photopic | Cones |
| Scotopic | Rods |
| Photographic Properties | Density, Contrast |
| Geometric Properties | Detail, Distortion |
| Density | Overall Blackness |
| Contrast | Differences in adjacent densities |
| Detail | Sharpness of lines |
| Distortion | Misrepresentation of the true size or shape of the image as compared to the object |
| Low Contrast | Many shades of grey |
| High Contrast | Black and white |
| Day Vision | Photopic |
| Night Vision | Scotopic |
| Veil Glare | Bright light floods the eye and reduces contrast perception |
| Mach Effect | The eye percieves a boundary between differing densities |
| Pattern Recognition | Comparing mental images of patterns to arrive at a diagnosis |
| Why two images at 90 * angles | To achieve a three dimensional image |
| Recorded Detail | What is on film |
| Visibility Detail | What we can see |
| mAs | Milliamp seconds-current times seconds |
| kVp | Kilovolt peak-energy of x-ray |
| Screen | turns x-ray into light |
| Grid | absorbs x-rays and improves contrast |
| Filtration | Absorbs low energy x-rays |
| Pathology | Changes density of tissues |
| SID | Source to Image Distance |
| High Density | Too Dark |
| Low Density | Too Light |
| Size Distortion | Always Magnification |
| Motion | Destroys detail |
| Communication to patient | Best way to control motion |