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Radiation Measures
Radiation Measurement Quiz | Answer |
---|---|
Gray | Absorbed dose |
Sievert | Dose equivalent (replaces REM) |
REM | Dose equivalent (occupational exposure) |
Curie | Original unit of radioactivity. |
Becquerel | Unit of radioactive decay |
Roentgen | Unit of exposure dose in air of x-rays. |
Rad | Absorbed dose (Patient Dose) |
A.L.A.R.A. | As Low As Reasonably Achievable |
The 3 Cardinal Rules of Rad Protection are: | Time, Distance and Shielding |
What are 3 Radiation sources? | Natural (cosmic rays, terrestrial), Industrial (Nuclear fuel, cosumer products) and Medical (x-rays, nuclear treatment) |
Distortion | Misrepresentation of size or shape of any anatomic structure |
Recorded detail | Ability to visualize small structures |
Contrast | Difference in density between any two areas on a radiograph |
Density | Degree of film blackening |
kVp | Primary controlling factor of radiographic contrast. |
kVp Formula: | cm (x) 2 + 40 = kVp |
What 3 factors control quality of radiographs? | mA, kVp and exposure time |
Reduce exposure for these conditions | Old age, Pneumothorax, Emphysema, Emaciation, Atrophy |
Increase exposure for these conditions | Pneumonia, Enlarged heart, Edema, Pleural effusion |
Source to Image Receptor Distance | Distance from anode inside x-ray tube to the image receptor. |
SID affects: | Magnification of body part, recorded detail, patient dose |
What are the 4 factors of radiographic quality? | Contrast, Density, Detail and Distortion |
The quantity of x-rays is dependent upon what? | mAs |
What unit is used to measure the quantity of radiation received by rad workers? | Rem |
How are milliamperage and time related to each other when used to maintain density? | Inversely proportional |
Which one of these factors (kVp, mAs) control radiographic DENSITY? | mAs |
Which one of these factors control radiographic CONTRAST? | kVp |
What does the rad and gray have in common? | They both measure absorbed dose. |
What does the Sievert and the Rem have in common? | They both measure the dose equivalent (occupational exposure) |
What is the kVp for a part that measures 8cm thick? | 56 kVp (8cm x 2 + 40) |