Spi Exam 2 Updated Actual Questions And Correct Answers

SPI EXAM 2 UPDATED ACTUAL
QUESTIONS AND CORRECT ANSWERS
Question:
1. why does reflection occur?
Answer:
result of impedance changes at an interface

Question:
2. interface
Answer:
boundary/reflector

Question:
3. if impedance goes up what happens to reflection
Answer:
goes up

Question:
4. acoustic impedance
Answer:
resistance to propagation of US waves through tissues

Question:
5. acoustic impedance image

Question:
6. reflection is
Answer:
when sound strikes a boundary between 2 media and some returns to transducer

Question:
7. reflection creates
Answer:
US image

Question:
8. two criteria must be met for reflection:
Answer:
1. different acoustic impedances
2. sound beam strikes boundary at 90 degrees (normal incidence)

Question:
9. when sound meets 2 interfaces:
Answer:
-part reflects back
-rest propagates through interface to next interface (transmission)

,Question:
10. reflection image

Question:
11. reflection ~
Answer:
foundation of US imaging

Question:
12. reflection is based on
Answer:
receiving & processing reflected acoustic energy (echo signals)

Question:
13. another reflection image

Question:
14. types of reflection
Answer:
-specular
-diffuse
-rayleigh scattering (back scattering)

Question:
15. specular reflection
Answer:
Mirror-like reflection, sound strikes large smooth surface

Question:
16. specular reflection is
Answer:
angle dependent (90 degrees)

Question:
17. interface is
Answer:
larger than 1 wavelength of incident wave

Question:
18. US wavelength in soft tissue
Answer:
0.1 to 0.8 mm

Question:
19. more artifacts in
Answer:
specular reflection

, Question:
20. sound beam part A
Answer:
incident beam- beginning sound beam

Question:
21. sound beam part B
Answer:
transmitted beam- what's continuing through

Question:
22. sound beam part C
Answer:
reflected beam- what's coming back to the machine

Question:
23. sound beam parts image

Question:
24. Obey Luez's Law
Answer:
applies ONLY with specular reflectors

Question:
25. angle of incidence =
Answer:
angle of reflection

Question:
26. Lue'z Law image

Question:
27. Specular reflection from head of humerus in shoulder

Question:
28. specular reflection from heart walls & mitral valve

Question:
29. Specular reflection from diaphragm

Question:
30. scattering from liver tissue helps
Answer:
depict parenchyma of an organ

Question:
31. scattering is
Answer:
small irregularities in liver tissue accentuate texture on the image