Question 1

Utilizing additional focal points causes the temporal resolution to __________.

Accepted Answer

Additional focal points will cause a decrease in the temporal resolution (frame rate).

Question 2

An increase in the number of channels ________.

Accepted Answer

An increase in the number of channels allows more precise control of the beam characteristics.

Question 3

Analog-to-digital converters convert the ________ voltage representing echoes to ________ for digital signal processing and storage.

Accepted Answer

Analog-to-digital converters convert the analog voltage representing echoes to numbers for digital signal processing and storage.

Question 4

The ________ is where the action originates.

Accepted Answer

The action originates in the beam former.

Question 5

Gain is the ratio of _____________________.

Accepted Answer

Gain is the ratio of amplifier output to input electric power.

Question 6

The display form that presents the depth in the vertical axis and the amplitude of the echo in the horizontal axis is ________.

Accepted Answer

A-mode presents a depth versus an echo-amplitude display.

Question 7

The ________ determines the brightness of the echoes on the display.

Accepted Answer

The digital-to-analog converter determines the brightness of the echoes on the display.

Question 8

A flat panel display presents image information in the form of ________.

Accepted Answer

Flat panel displays present image information in the form of horizontal lines.Each horizontal display scan line corresponds to a row of digital data in image memory.The information is read out of memory,row by row,like writing on a lined sheet of paper (from left to right).

Question 9

A two-dimensional image plane is usually divided like a checkerboard in a ________ or similar matrix.

Accepted Answer

A rectangular matrix measures 1024 × 768 or 512 × 384.

Question 10

When the fundamental frequency is filtered out,which of the following occurs?

Accepted Answer

In harmonic imaging,the fundamental (transmitted) frequency is filtered out and the second harmonic frequency echoes are passed.

Question 11

The pulse delays have a ________ input from the pulser but ________ output(s) to the transducer element.

Accepted Answer

The pulse delays have a single input from the pulser but multiple outputs to the transducer element.

Question 12

A digitizer _______________.

Accepted Answer

A digitizer (analog-to-digital converter) converts the voltage from analog to digital form.

Question 13

The maximum frame rate permitted for a 15 cm penetration depth,three focuses,and 200 scan lines per frame is ________.

Accepted Answer

The answer of The maximum frame rate permitted for a...

Question 14

In order to image deeper structures,the ________.

Accepted Answer

For deeper imaging,echoes take longer to return,thus forcing a reduction in the PRF and frame rate.

Question 15

Golay codes ________.

Accepted Answer

Golay codes use pairs of transmitted pulses with the second being a bipolar sequence.

Question 16

Which of the following reformats data into image form for processing,storage and display?

Accepted Answer

The digitizer reformats data into imaging form for image processing,storage,and display.

Question 17

When gain is too high,which of the following occurs?

Accepted Answer

With too much gain,saturation occurs; that is,most echoes appear bright and differences in echo strength are lost.

Question 18

The pulse repetition frequency (PRF) in real time imaging typically ranges from ________.

Accepted Answer

The PRF in real time imaging typically ranges from 4 to 15 kHz.

Question 19

Panoramic imaging expands the image ________.

Accepted Answer

Panoramic imaging expands the image beyond the normal limits of a transducer's field of view.

Question 20

The primary beam is much narrower,improving lateral resolution with ________.

Accepted Answer

The primary beam is much narrower,improving lateral resolution because harmonics are generated only in the highest-intensity portion of the beam.

Quiz 4: Instruments