Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OB Ultrasound > Physics Chapter 15 - 17 > Flashcards

Physics Chapter 15 - 17 Flashcards

1
Q

A word of computer memory consists of:

A

2 bytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

One of the limitations of an analog scan converter is:

A

image fade

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Analog numbers can have an unlimited and continuous range of values. TRUE or FALSE.

A

True.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

The 2 important elements of digital scan converters are:

A

Pixel and Bit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The spatial resolution of an analog scan converter is excellent because the large number of storage elements with the ______.

A

matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Decimal numbers are based on ten choices which range from

A

0-9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How many possible shades of gray are displayed with 4 bits of memory?

A

16

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Any processing of the reflected signals BEFORE storage is

A

preprocessing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

With regards to read magnification, is the ROI rescanned. YES or NO.

A

NO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The FDA has put a limit on the maximum peak intensity levels for sound beams, this is called

A

coded excitation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

This is a method of describing the extent to which a signal can vary and still maintain accuracy.

A

dynamic range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

PACS stands for

A

Picture Archiving and Communications System

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

DICOM stands for

A

Digital Imaging and Computers in Medicine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

This technique is used to image the changes in tissue when they are deformed differently and following the application of force. The stiffness data and ultrasound reflections are combined into images. It is called

A

elastography

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

This is a processing method that makes pictures look sharper. The computer identifies and emphasizes sharp edge boundaries in the image. It is called

A

edge enhancement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Harmonic frequency sound waves arise from linear behavior. True or False

A

False

17
Q

If you are scanning in fundamental frequency at 4 MHz, what would it be in harmonics?

A

8 MHz

18
Q

Would you get a better image in harmonics scanning in superficial or deeper tissues?

A

deeper

19
Q

. Beams that are most likely to create harmonics are more likely to create artifacts. TRUE or FALSE

A

False

20
Q

Contrast agents must meet all of these requirements except which one:

A

large enough to pass through the capillaries

21
Q

Which of the following does not belong for the low mechanical index

A

resonance

22
Q

Which of the following does not belong for the highest mechanical index

A

linear behavior

23
Q

Where are harmonics created

A

in the tissues

24
Q

Contrast harmonics created by microbubbles are much stronger than tissue harmonics. TRUE or FALSE.

A

True

25
Q

In this imaging technique, the reflections from the first pulse are doubled and then subtracted from the second reflection. The fundamental portions of the 2 reflections completely cancel each other out, leaving only the harmonic portion of the second reflection. The remaining harmonics form an image with less distortion than the fundamental image. This is called

A

power modulation harmonics

26
Q

An uncompressed signal has a dynamic range of 85 dB. The signal undergoes 40 dB of compression. What is the dynamic range of the compressed signal?

A

45 dB

27
Q

A signal within a system’s receiver has a dynamic range of 70 dB after compression. The original signal was compressed by 40 dB. What is the dynamic range of the original, uncompressed signal?

A

110 dB

28
Q

With frequency compounding how many pulses are transmitted down each scan line?

A

1

29
Q

What is the primary storage device on a PACS system?

A

hard disc drives

30
Q

Are the following procedures usually pre or postprocessing

a. modifying a frozen image——-PRE or POST
b. read zoom ——PRE or POST
c. write zoom —-PRE or POST
d. adjusting the brightness on the monitor—-PRE or POST
e. increasing the receiver gain—-PRE or POST

A

a-Post b-Post c-Pre d-Post e-Pre

31
Q

Which of the following is not a form of magnetic media?

A

laser discs

32
Q

What is not an advantage of paper media?

A

bulky

33
Q

What is a disadvantage of optical media?

A

no standardized format from image display and storage

34
Q

Which of the following scan converters will provide the best spatial resolution?

A

1000 X1000 pixels

35
Q

This imaging technique continues to display information from older images.

A

temporal compounding

OB Ultrasound (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions