Lesson 16 Flashcards
How many kinds of scanning are there?
3
What are the kinds of scanning? (3)
- Mechanical scanning
- Automatic scanning
- Electronic scanning
- similar to automatic scanning
Mechanical transducer
Single element, fixed with a motor
What do you do with a mechanical transducer?
Place the probe on the patient and sweep it back and forth and produce a sector
What kind of scanning is automatic scanning? (2)
- Live scanning
- The probe is constantly sending out pulses and receiving echoes
- building images even when you are holding still
- shows images in sequence so it looks like a live scan
What do you need in order to do electronic scanning?
More than one single element
- need arrays
What shape are arrays?
Usually rectangular
- assembled in a row
How many types of arrays are there?
2
What are the 2 types of arrays?
- Linear
2. Convex
What are the 2 ways to operate linear arrays?
- Linear sequenced array
2. Linear phased array
What is a type of linear phased array?
Vector array
Linear array
Several elements in a row
What does linear sequence array involve?
Firing groups of elements at the same time
- so they overlap each other
- fast segments
What would the aperture be in linear sequenced array?
It would be apart of the group that you are firing
- width of the group
What will each group do in linear sequenced array?
Each group will produce a pulse and receive an echo
- produce a scan line of information
What do multiple scan lines produce?
A rectangular image
What is the width of the image?
The length of the array
What do linear sequenced array consist of?
Parallel scan lines, travelling in the same vertical direction
LPF
Lines per frame
Lines per frame
Number of scan lines in a frame
What makes a frame?
Individual scan lines building up
What is a frame?
Imaged stored in the memory
- can be retrieved
What does more LPF mean?
Production of better quality images
What are 2 types of convex arrays?
- Convex sequenced array
2. Convex phased array
How does a convex/curvilinear sequenced array work?
Same and a linear sequenced array
What does a curvilinear sequenced array produce?
A modified sector image
What does the width in the scan plane determine?
The lateral resolution
What does an ultrasound beam consist of? (2)
- Near zone
2. Far zone
