Physics of US

Question 1

Wavelength

Answer 1

C/frequency

C=1600 m/s

Question 2

Spatial resolution

Answer 2

Minimal distance between 2 objects the image can detect

Question 3

Temporal resolution

Answer 3

Minimal time between 2 events that dynamic images can depict

Increase by increasing frame rate at a cost of spatial resolution

Question 4

Contrast resolution

Answer 4

Minimal difference in the parameter displayed in the image as distinct pixel intensities

Question 5

Dynamic range

Compression

Answer 5

Difference between highest and lowest amplitude signals reecived

High=shades of gray
Low=black-white contrast

Question 6

Phased-array transducers

Answer 6

Differences in phase of pulses transmitted by individual elements to steer US beam in diffrent directions thus scan a “slice” rather than single line