MSK US physics 2 Flashcards
What is lateral resolution?
Ability to distinguish between two structures that are side by side
What is a linear array transducer?
Fixed focus and linear sequential array
What is a phased array transducer?
adjustable focus, phasing and steering
What is the difference between spatial contrast and temporal resolution?
temporat is the ability to locate moving structures at an instant in time
What will the time gain compensation allow?
sonographer to adjust the compensation at various depths time along the beam
What is Harmonic Imaging
2x the fundamental freqeuncy aka 2nd harmonic
What is dynamic range?
echoes processed from strongest to weakest
What is a Doppler shift
Positive change and negative change they indicate a shift not amplitude
What does the color bar indicate on the machine?
blood flow toward the transducer and away from the transducers
What is Aliasing and what velocity appears negative
High velocities appear negative. Occurs when the pulsed doppler samping rate (PRF) is mcuh lower that the measured doppler shift
What is a wall filter?
reject low level doppler shifts
What is the artifact of reverberation?
multiple echoes apperar
What is the artifact of a comet tail or ring down
solid line along the path of the US beam that is created by small metal or calcified objects
What is an artifact of shadowing
US beams cannot pass through the material
What is an artifact of Edge shadowing
Angle dependent form of shadowing
What is an artifact of Enhancement?
Propagation velocity based artifact that creates hyperechoic echoes deep to the initial structure
What is an artifact of a Mirror Image?
Creates a duplicate by bouncing off a strong reflector and redirected
What is an artifact of refraction artifact?
angle of beam is changed creating an artifact presenting the structure duplicated and side by side
what is in plane needle visualization
perpendicular relationship to see the entire full length reflection of the needle
Image of the very close probe with shallow targets
Needle entry site
