Study guide 14, 15 Flashcards
- Which component organizes in times functions?
Master Synchronizer
- Which component excites the crystal?
Pulser (JL pg 217)
- Choose the area on TGC where attenuation is occurring?
In the region of the slope, compensation corrects for the effects of increasing attenuation
- What creates the pattern for phased array firing?
Beam Former
- Make sure you know the functions of the receiver?
- amplification
- Compensation
- compression
- Demodulation
- Reject- Yes it is adjustable, Only weak signals affected; strong signals remain unchanged, Week echoes appear or are eliminated from image
- Who decides the acoustic power of the sound beam ?
voltage (question 5 pg 237)
- In regards the pulser which form has the electrical signal and sine wave ?
Continuous Wave (JL p236 Q: 2)
- Know what can improve the signal and noise ratio (higher)?
Output power improves or degrades signal and noise ratio
- If an image is to dark or to bright what are your options/what tools may you use to improve the image?
Amplification or output power
- Another receiver question/know about reflector depth which receiver function can change that ?
PRP (pulse repetition period)
- Know about PRP and PRF?
They are inversely related. Shallow imaging- Shorter listening time, shorter PRP, Higher PRF Deep Imaging- Longer listening time, longer PRP, lower PRF
- Know the components about an U/S system
pg 216 Transducer, pulser/beam former, receiver,display,storage,and master synchronizer
- Know which choices to use when you have to much brightness on your image which would be a better choice-
Amplification is the better choice due to bioeffects and ALARA
- Which function effects the strength of every signal?
Compression
- Know the dis advangtes of analog scan converter?
Image fade, Image flicker, Instability, Deterioration
- As well as the advantages of a digital scan converter?
Uniformity, Stability, Durability, Speed, Accuracy
- You need to know what is responsible for the gray scale imaging?
Analog Scan converter
- Questions of shade of gray and bits know how to convert those
2 ^number of bits (JL pg 246)
19. Uses old data Postprocessing Larger pixel size Same # of pixels as in the original ROI Unchanged spatial resolution Unchanged temporal resoltuion
Read (zoom)
19. Acquires new data Preprocessing Identical pixel size More pixels than in the original ROI Improved spatial resolution May improve temporal resolution
Write (zoom)
- Know the functions that are Preprocessing
Manipulation of image data before storage in the scan converter. Alters the image data forever and cannot be reversed or undone.
- Function of Postprocessing
Manipulation of image data after storage in the scan converter. The changes can be reversed, Any alteration to a frozen image.
Time gain compensation Log compression Write magnification Persistence Spatial compounding Edge enhancement Fill-in interpolation
Preprocessing
Any change after freeze frame Black/white inversion Read magnification Contrast variation 3-D rendering
Postprocessing
Yes it is adjustable, All signals treated identically, Entire image gets brighter or darker
Amplification
Yes it is adjustable, Signals treated differently based on reflector depth, Image will be uniformly bright from top to bottom
*Compensation
Yes it is adjustable, Signals treated differently depending on strength, Changes gray scale mapping
*compression
No it isn’t adjustable, Prepared electrical signals to be suitable for display, No effect on the image
*Demodulation
Yes it is adjustable, Only weak signals affected; strong signals remain unchanged, Week echoes appear or are eliminated from image
*Reject
