Chapter 11: Display Modes

Three basic formats of viewing ultrasound information

1. Amplitude Mode

2. Brightness Mode

3. Motion Mode

What does A-Mode (Amplitude) appear as?

A series of upward spikes.

What does a bigger spike in A-Mode indicate?

A bigger reflection.

What is the relationship between the height of the upward deflection and the amplitude of the returning echo in A-Mode?

The height is proportional to the amplitude; strong echoes produce tall spikes, weak echoes produce short spikes.

What does the X-axis represent in A-Mode?

Reflector depth.

What does the Y-axis represent in A-Mode?

Reflection amplitude.

As a sound pulse is emitted by the transducer what occurs?

A dot moves at a constant speed across the system's display

When a reflection returns to the transducer, what occurs?

It is processed and the moving dot is deflected upward on the screen

A-Mode is accurate in determining what?

Depth of reflectors

What modality is A-Mode frequently used in?

Opthalmology

What does the brightness of the dot in B-Mode indicate?

The strength of the reflection.

In B-Mode imaging, what does a darker gray dot represent?

Weaker reflections.

In B-Mode imaging, what does a brighter white dot represent?

Stronger reflectors.

What was the first form of gray scale imaging?

B-Mode.

As a sound pulse is emitting by the transducer what occurs in B-Mode?

An invisible dot moves at a constant speed across the system's display

When a reflection returns to the transducer, what occurs in B-Mode?

It is processed and the invisible dot is turned on

X-axis in B-Mode

depth

Z-axis in B-mode

amplitude

What does M-mode (motion) appear as on a display?

A group of horizontal wavy lines.

What does a line that moves up and down on the M-mode display indicate?

A reflector is moving closer to or further away from the transducer.

In M-mode, what does the X-axis represent?

Time.

In M-mode, what does the Y-axis represent?

Depth.

What unique information does M-mode provide?

Information about a reflector's changing location with respect to time.

What is M-mode used to obtain?

A heartbeat.

sampling rate is

high and equal to the PRF