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Varkey ex.1 study gd
ch.23-24
Question | Answer |
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1. What is the difference between screening, diagnostic and base line mammogram? (How many views?) | -Screening:performed on asymptomatic women, 50 years or older,(min 2 views) -Diagnostic:Performed on patients with symptoms or elevated risk factors(2/3 views) -Baseline:The first radiographic examination of the breasts,Usually done before age 40 |
2. Three different types of breast tissues are ____________, ______________, and ____________ | -Fibrous -Glandular -Adipose |
3. 80% of the breast cancer is __________________. | ductal |
4. A double emulsion film is used in mammography. True or False? | false its single |
5. What are the three target materials commonly used in a mammographic x-ray tube? | -Tungsten (W) -Molybdenum (Mo) -Rhodium(Rh) |
7. _____________________________produces characteristic x-rays with energy of 19 keV | Molybdenum (Mo) |
8. _____________________________ produces characteristic x-rays with energy of 23 keV | Rhodium (Rh) |
9. What are the filters commonly used in mammographic x-ray tubes? | -Mo/Mo -Mo/Rh -Rh/Rh |
10. Commonly use focal spot size in mammographic x-ray tubes are_______________ | 0.3/0.1 mm.(large/small) |
11. The anode angle in a mammographic x-ray tube is ______________________ | 23° to obtain focal spot of 0.3/0.1mm |
12. The x-ray tube is tilted ________ degrees in a mammographic unit. | 6° to obtain focal spot of 0.3/0.1mm |
13. What is the advantage of tilting the x-ray tube in a mammographic unit? | -Provide smaller effective focal spot. -Ensure the imaging of the tissue next to the chest wall. -When the tube is tilted the central ray becomes parallel to the chest wall and no tissue is missed. |
14. The glass window of the mammographic nit is usually _____________ or ______________ | -A Beryllium (Z=4) window or -a very thin Borosilicate glass window. |
15. In mammography the total beam filtration should not be less than ____________________ | 0.5mm of Al equivalent |
16. Thick dense breasts are imaged better with ___________________ target filter combination | Rh/Rh target filter combination. |
A tungsten target x-ray tube should have a | Molybdenum or Rhodium filter(50um). |
A Molybdenum target x-ray tube should have | Mo filtration of 30 um or Rh filtration of 50 um. |
A Rhodium target x-ray tube should have | a Rh filter of 25 um |
17. Thin fatty breasts are image better with ______________________ target filter combination. | Mo/Mo target filter combination. |
18. Spatial resolution is less at the ______________side of the mammographic x-ray Tube. | anode |
19. What is the advantage of giving breast compression during a mammographic examination? | -A compressed breast is more uniform in thickness and therefore the optical density of the image is more uniform. -Tissues nearer the chest wall are less likely to be underexp -Tissues nearer the nipples are less likely to be overexp -lower pt dose |
19. What is the advantage of giving breast compression during a mammographic examination? (continued) | -Reduced focal spot blur (compression brings tissues closer) -Reduce absorption blur -Reduce scatter -Improve spatial res/contrast res -Reduce motion blur -Reduces the superimp of tissue structures because compression spreads out the tissue. |
20. What is the common grid ratio used in mammography? | 4:1 to 5:1. |
21. What is the common grid frequency used in mammography? | 30 to 50 lines /cm. |
22. Name a special type of grid used in Mammography. | High transmission cellular grid (HTC) |
23. What is the purpose of a quality control program? | |
24. How often a screen film contract is tested? | semi anually |
25. Effective focal spot should not exceed ______________in magnification mammography | 0.1mm |
26. The CCD is a solid state device that converts _________ photons to electrons. | visible light |
27. CCD is made up of ____________________ or _____________________ | amorphous silicon or amorphous selenium. |
28. The electronic noise in digital mammography can be reduced by ______________________ | cooling the detector |
29. Cooling the detector will improve contrast resolution. True or False? | True |
30. What are the advantages of digital mammography? | -Ability to post-process the image -Enhanced contrast resolution. -However, digital imaging can only provide a spatial resolution of 8 to 10 lp /mm. compared to 20 lp/mm for screen film) |
30. What are the advantages of digital mammography? (continued) | -But this is adequate because of the enhanced contrast resolution available with post-processing |
The response of a CCD is _________, not curvilinear as with screen film. | linear |
32. _______________ is the most hands-on member of the QC team. | Mammographer |
34. For an accurate result at least _________ mammograms should be included in the analysis. | 250 |
Phantom images (If the phantom images results in any of the factors exceeding the control values, the cause should be investigated and corrected as soon as possible) | -are taken to ensure optimal OD, contrast, uniformity and image quality of the x-ray imaging system and film processor. -should also be taken after equipment installation and major equipment maintenance. |
35. Repeat rate of ____________% is acceptable. | 2% |
36. ________ is an imaginary pivot point about which the x-ray tube and the image receptor move. | fulcrum |
Repeat rate (%) = Number of repeated films X 100/ Total number of exposed films | |
37. The ______________ the tomographic angle, the thinner the section is. | larger |
A ___________ is performed to evaluate screen film contact | wire mesh test |
(tomography) The angle of movement of the x-ray tube is known as the | tomographic angle. |
The thickness of tissue imaged is called the | tomographic layer. |
38. What are the factors that control the blur on a tomographic image? | 1) Distance of object from the focal plane. 2) Exposure Angle. 3) Object image Receptor Distance (OID). 4)Tube trajectory |
-Tomography : Body section radiography -Tomogram: Radiograph produced by tomographic process. -Fulcrum: The pivot point between the x-ray tube and the IR -Exposure angle: The angle resulting from the x-ray beam movement. | Fulcrum level: Distance measured in centimeters or inches, from the tabletop to the fulcrum Objective plane=Focal plane: The plane in which the object is clear and in focus. |
39. How can you change the thickness of a tomographic layer? | by changing tomographic angle |