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image production 2
| Question | Answer |
|---|---|
| What are the two basic properties of X-Ray Beam? | Quantity and Quality |
| What are the 3 factors of quantity? | Amount, Intensity, and Exposure Rate |
| What are the 3 factors of quality? | Strength, Penetrating Power, and Hardness |
| What the 4 factors that directly control intensity? | mAs, kVp, SID/FFD, OID/OFD |
| 1000 mAs= | 1 As |
| 1000 V = | 1 kVp |
| What does SID and FFD mean? | Source to image recptor distance and focal film distance |
| What does OID/OFD mean? | Object to image receptor distance and object to film distance |
| mAs is ______ ______ to density | directly proportional |
| The amount of blackness on the film | Density |
| What ever you do to mAs you should you do to density? | the same thing |
| The density produced on the film will be directly proportional to the exposure recieved by the film | Reciprocity law |
| When you increase mAs what does that do to the electrons? | increases the number of projectile electrons boiled off at the filament of the x-ray tube (thermionic emission) |
| What happens to the photons during thermionic emission? | It increases the number of photons produced at the anode |
| A minimum change of at least___ in mAs is required to produce a significant increase or decrease in density | 30% |
| If you were using 10 mAs and the film came out too light what would you do and what is your new mAs? | you would increase you mAs by 30% which is 13 because 30% of 10 is 3 the add that to 10 |
| If your film came out too dark when using a 20mAs what would you do? | you would decrease 20mAs by 30% which would give you 14 |
| mAs = | mA x Time |
| what is the decimal and millisecond of 1/10 | .10 and 100 1 divide by 10 is .10 then .10 multiplied by 1000 is 100 |
| what does kVp stand for | kilovoltage Peaks |
| What does the kVp affect | bothe the wavelength and the frequency of the x-ray photon |
| As kVp is increased how is the wavelength and frequency affected? | the wavelength of the photon is decreases and the frequency is increased |
| what is the controlling factor of contrast | kVp |
| the percentage of the differences between the extreme blacks and whites on the radiograph | Contrast |
| If you increase kVp what do you do to contrast | decrease contrast |
| when you increase constrast what do you do to the inensity | increase it |
| when you increase kVp what do you do to density | increase density |
| what is the rule when increasing kVp or decreasing kVp does it do to density | 15% rule if you increase by 15% you double density but if you subtract 15% you cut density in half |
| There is a minimum change of____ in kVp that is required before a visible change in density can be seen | 8% |
| Pathological conditions that alter normal tissue in such a way to make it hard to penetrate (radiopaque) | Additive disease |
| Pathological condition that alters normal tissue in such a way to make it easier to penetrate (radiolucent) | destructive |
| Tell in the next 41 sildes whether they are additive or destructive and what do you do to mAs or kVp | |
| Proliferative Arthritis | Additive increase 50% mAs |
| Bone callus | Additive increase 50% mAs |
| Exostosis | Additive increase 50% mAs |
| Hydrocephalus | Additive increase 50% mAs |
| Osteochondroma | Additive increase 50% mAs |
| Osteopetrosis | Additive increase 50% mAs |
| Osteoma | Additive increase 50% mAs |
| Padgets Disease | Additive increase 50% mAs |
| Osteoarthritis | Additive increase 50% mAs |
| Acromegaly | Additive increase 50% mAs |
| Sclerosis | Additive increase 50% mAs |
| Pneumonia | Additive increase 50% mAs |
| Pneumoconiosis | Additive increase 50% mAs |
| Atelectasis | Additive increase 50% mAs |
| Pulmonary edema | Additive increase 50% mAs |
| Lung Abscess | Additive increase 50% mAs |
| Pleural Effusion | Additive increase 35% mAs |
| Cardiomegaly | Additive increase 50% mAs |
| Pericardial Effusion | Additive increase 50% mAs |
| Hydrothorax | Additive increase 50% mAs |
| Aneurysm | Additive increase 50% mAs |
| Ascites from Hepatic Cirrhosis | Additive increase 50% mAs |
| Ascites from bowel perforation | Additive increase 50% mAs |
| Edema | Additive increase 10% kVp |
| Morbid obesity | Additive increase 10% kVp |
| Destructive arthritis | Destructive decrease 10% kVp |
| Necrosis | Destructive decrease 10% kVp |
| Osteopenia | Destructive decrease 10% kVp |
| Osteomalacia | Destructive decrease 10% kVp |
| Atrophy | Destructive decrease 10% kVp |
| Bone Abscess | Destructive decrease 10% kVp |
| Osteoporosis | Destructive decrease 15% kVp |
| Emphysema | Destructive decrease 15% kVp |
| Pneumothorax | Destructive decrease 15% kVp |
| Ileus | Destructive decrease 10% kVp |
| Emaciation | Destructive decrease 10% kVp |
| How do you double the density of 80 kVp | take 15% of 80 which is 12 the add 12 to 80 which gives you 92 |
| How to you cut the density in halp when using 60kVp | you take 15% of 60 which is 9 then subtract 60-9 which gives you 51 |
| If you increase the SID what do you do to the intensity of the beam and why | decrease it because of the divergence of the beam |
| There must be a ____ chang in distance to cause a visible change in density and require an adjustetment in technique | 20% |
| SID and density are | inversely proportional |
| The intensity or exposure rate of radiation is inversely propotional to the square of the distance from the point of source | Inverse Square Law |
| if the orginal intensity was 200mR and the orginal distance was 40 what will the new intensity be if the new distance is 60 | 88.89mR |
| If the orginal mAs was 5 and the orginal distance is 40 what new mAs should be used to compensate for the distance changing to 80 | 20 mAs |
| What are the prime factors of the x-ray beam | Density, Contrast, Detail, and distortion |
| The overall backness on the radiograph | density |
| What is density compromised of | Primary, Remnant, scatter/secondary radiation |
| Radiation exiting the tube | Primary Radiation |
| Primary radiation that exits the patient. This is the image forming part of the beam | Remnant Radiation |
| Primary radiation that has changed direction or has produced other radiation that travels in a different direction | Scattered/ Secondary Radiation |
| What are the 4 body habitus | Hyppersthenic, Sthenic, Hyposthenic, and Asthenic |
| Large body Frame | Hypersthenic |
| Average size patient | Sthenic |
| A thin patient | Hyposthenic |
| Athin patient with a very small body frame | Asthenic |
| What body habitus requires the highest exposure | Hypersthenic |
| What body habitus requires the lowest exposure setting | Asthenic |
| Tissue that allows radiation to pass through freely | Radiolucent |
| Appears darker on the radiograph | Radiolucent |
| Tissue that absorbs radiation | radiopaque |
| Appears lighter on the film | radiopaque |
| Instrument used to measure the thickness of a body part | Calipers |
| Where do you palce the caliper on the body | where the central ray will enter the body |
| You shoul never______ the caliper | squeeze |
| What is the rule in changes for the average thickness of the body tissue | As a general rule, add 2Kvp for every centimeter increase in tissue thickness and subtract 2 kVp for every centimeter decrease in tissue thickness from the average size part |
| The intensity across the beam can vary as much as _____ | 45% |
| The is caused by increased absorption of the primary beam by the heel of the anode/target | Heel effect |
| This is more noticeable as the SID is lowered | The heel effect |
| What does the smaller focal spot affect | The larger field size will be and thegreater the heel effect |
| The cathode side of the tube should be placed where and why? | over the thicker part of the anatomy to produce a more uniform density (dorsal spine and femur) |
| what is the photographic effect equation | (mA)(time)(kVpsquare)/Distance in cm squared |
| 1 inch equals how many centimeters | 2.54 |
| What is the equation for exposure | multiply you answer for photographic effect by 15 |
| If you increase mA what do you do to density | increase density |
| If you increase exposue time what do you do to density | icrease density |
| If you increase kV what do you do to density | increase density |
| If you increase SID what do you do to density | decrease density |
| If you increase OID what do you do to density | decrease density |
| If you increase screen speed what do you do to density | Increase density |
| If you increase film speed what do you do to density | Increase density |
| If you increase grid factor what do you do to density | decrease density |
| If you increase beam restrition what do you do to density | decrease density |
| If you increase beam filtration what do you do to density | decrease density |
| If you increase Collimation what do you do to density | decrease density |
| If you increase the thickness of the part what do you do to density | decrease density |
| If you increase Compression what do you do to density | decrease density |
| If you decrease atom # what do you do to density | decrease density |
| If you increase processsing time/temp what do you do to density | increase density |
| If you increase the focal spot what do you do to density | no effect |
| If you increase image receptor angulation what do you do to density | no effect |