(a)   mode displays are created as a sound pulse is emitted by the transducer, a dot moves at a constant speed across the systems display

(a)   mode displays are created when a reflection returns to the transducer, it is processed and the moving dot is deflected upward on the screen

The height of the upward deflection is (a)   to the amplitude of the returning echo

Strong echoes create (a)   spikes

Weak echoes create (a)   spikes

Which mode is accurate in determining the depth of reflectors?

(a)  

Which mode is bi-dimensional? Depth & post?

(a)  

Dots of brightness

(a)  

(a)   mode appears as a line of dots of varying brightness.

(a)   mode displays are created when a pulse is emitted by the transducer, an invisible dot moves at a constant speed across the systems display

(a)   mode displays are created when a reflection returns to the transducer, it is processed and the invisible dot is turned on

The brightness of the dot indicates the (a)   of the reflection

Horizontal wavy lines

One dimensional

(a)  

(a)   mode appears as a group of horizontal wavy lines

(a)   mode displays are created as a sound pulse is emitted by the transducer, the reflections move at a constant speed from right to left across the screen

(a)   mode displays are created when 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 __ to or __ away from the transducer

(a)  

A straight horizontal line indicates a (a)   reflector

Since M-mode ultrasound information arises from a single penetration into the body the "sampling rate" of M-mode is very (a)   and equal to the PRF

The sampling rate of M mode is equal to (a)   of the system

X-axis = depth

Y axis = amplitude

(a)  

X axis = depth

Z axis=amplitude

(a)  

X-axis = time

Y-axis = depth

(a)  

(a)   is the most used modality that allows displaying virtual representations of anatomical cross sections.

In two dimensional imaging, sound beams travel in a (a)   line and must be narrow to optimized lateral resolution.

In two dimensional imaging, sound beams travel in a straight line and must be (a)   to optimized lateral resolution.

In two dimensional imaging, sound beams travel in a straight line and must be narrow to optimized (a)   resolution.

The creation of sound beams in two dimensional imaging is an (a)   process in the transducer

The (a)   transducer contains a single, circular, disc shaped active element that is mechanically steered

How many active elements can a mechanical transducer have?

(a)  

The mechanical transducers active element is shaped like a (a)  

The two dimensional image is built up by rotating the crystal with a (a)  

Conventional, mechanical, or fixed focusing are also names for (a)  

Internal and external focusing are two methods of (a)  

Focusing occurs in both horizontal and vertical planes because of the ___ ___ shaped sound beam

(a)  

(a)   arrays contain multiple active elements

An (a)   comprises of a single slab of PZT cut into. collection of separate pieces called elements

Electronic scanning, multiple elements

(a)  

Each (a)   is connected by a wire to its own circuitry in the ultrasound system.

A (a)   is the combination of the active element, wire, and system electronics

Each (a)   is a channel.

How many scan lines are originated by a channel?

(a)  

All the channels fired once produce a (a)  

#channels = #scan lines

(a)  

Active elements are arranged in a straight line

(a)  

Elements are arranged as circular rings with a common center

(a)  

Active elements are arranged in a bowed or arched line. The transducer may also be called curved or curvilinear array.

(a)  

The complete sequence of firing all the crystals of the array is done repeatedly a number of times per second

(a)  

Usually, greater than 20-25 times per second

(a)  

In the average, (a)   times/sec in order to avoid “flickering” of the image

(a)   increase the number of scan line, which then results in better line density

The __ __ transducer is compact, a small square that is about 1-2cm on each side.

(a)  

The __ __ has a small footprint that is square

(a)  

The beam is steered and focused using an electrical technique called (a)  

Phased steering without using moving parts; focused

(a)  

Potentially multi-focus (multiple beams in same scan line with different focal lengths)

(a)  

Steering and focusing done with time delays in the order microseconds (steering) and nanoseconds (focusing)

(a)  

Sonographer can modify position and number of focus

(a)  

In which type of transducer are crystal very small, around 1/4 wavelength wide?

(a)  

In which type of transducer are there as many as 100-300 elements in a 1-2cm space?

(a)  

Fired as a unit at almost the same time.

(a)  

In a linear phased array, the two dimensional image is built up with electronic steering process called (a)  

The sound beams are electronically transmitted in different directions (a)   the use of moving parts in a linear phased array

active elements in a ___ ___ array probe are fired to create each so Allund pulse

(a)  

Electrical spikes

Elements

Each element creates a wavelet which interact to produce a single sound beam    

(a)  

Slope of the electrical spike line determines the direction of the sound beam.

Phase delays in order of 10 nanoseconds

(a)  

Overall pattern of the (a)   determines the sound beam’s steering and focus - Linear phased array

The outer elements in the group of crystals are excited earlier then the inner elements.

(a)