chapter 11: display modes

what are the 3 basic modes of display or formats of viewing ultrasound info?

• amplitude mode

• brightness mode

• motion mode

A-mode (amplitude)

accurate in determining the depth of reflectors

A-mode appearance:

appears as a series of upward spikes

how are A-mode displays created?

1st: a sound pulse is emitted by the transducer and a dot moves at a constant speed across the system’s display

2nd: when a reflection returns to the transducer, it is processed and the moving dot is deflected upward on the screen

in A-mode, the height of the upward deflection is proportional to the:

amplitude of the returning echo

in A-mode, the x-axis represents:

reflector depth

in A-mode, the y-axis represents:

reflection amplitude

A-mode is extensively used in what healthcare setting?

ophthalmology

B-mode (brightness)

the first form of gray scale imaging and is the basis for all other types of gray scale imaging including real-time imaging

B-mode appearance:

appears as a line of dots of varying brightness

how are B-mode displays created?

1st: a sound pulse is emitted by the transducer and an invisible dot moves at a constant speed across the system’s display

2nd: when a reflection returns to the transducer, it is processed and the invisible dot is turned on

in B-mode, the brightness of the dot indicates:

the strength of the reflection

in B-mode, the x-axis represents:

reflector depth

in B-mode, the z-axis represents:

amplitude

M-mode (motion)

provides information about a reflector’s changing location with respect to time

M-mode appearance:

appears as a group of horizontal wavy lines

how are M-mode displays created?

1st: a sound pulse is emitted by the transducer and the reflections move at a constant speed from right to left across the screen

2nd: various squiggly lines that represent the changing depth of the reflecting surfaces are produced on the screen

a line that moves up and down on the display indicates:

that a reflector is moving closer to or farther away from the transducer

in M-mode, the x-axis represents:

time

in M-mode, the y-axis represents:

reflector depth

M-mode is primarily used to assess:

the motion of cardiac walls and structures