Chapter 15-17 test

Question 1

A word of computer memory consists of

Answer 1

2 bytes

Question 2

One of the limitations of an analog scan converter is:

a. stability
b. durability
c. image fade
d. speed

Answer 2

image fade

Question 3

TRUE OR FALSE

Analog numbers can have an unlimited and continuous range of values

Answer 3

True

Question 4

What are the two important elements of digital scan converters

Answer 4

Pixel and bit

Question 5

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

a. matrix
b. monitor
c. electron gun

Answer 5

Matrix

Question 6

Decimal numbers are based on ten choices which range from

Answer 6

0-9

Question 7

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

Answer 7

16

Question 8

Any processing of the reflected signals BEFORE storage is

a. preprocessing
b. postprocessing

Answer 8

preprocessing

Question 9

YES OR NO

with regards to rad magnification, is the ROI rescanned

Answer 9

No

Question 10

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

a. temporal compounding
b. coded excitation
c. edge enhancement
d. frequency compounding

Answer 10

Coded excitation

Question 11

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

a. spatial resolution
b. harmonics
c. dynamic range
d. threshold

Answer 11

dynamic range

Question 12

PACS stands for

Answer 12

Picture Archiving and Communications Systems

Question 13

DICOM stands for

Answer 13

Digital Imaging and Computers in Medicine

Question 14

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. fill-in interpolation
b. elastography
c. temporal compounding
d. edge enhancement

Answer 14

elastography

Question 15

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
b. spatial compounding
c. elastography
d. frequency compounding

Answer 15

Edge enhancement

Question 16

TRUE OR FALSE

Harmonic frequency sound waves arise from linear behavior?

Answer 16

False

Question 17

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

Answer 17

8MHz

Question 18

Would you get a better image in harmonics scanning in SUPERFICIAL or DEEPER tissues?

Answer 18

Deeper

Question 19

TRUE OR FALSE

Beams that are most likely to create harmonics are more likely to create artifacts

Answer 19

False

Question 20

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

a. safe
b. long lasting
c. large enough to pass through the capillaries
d. metabotically inert

Answer 20

c. large enough to pass through the capillaries

Question 21

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

a. backscatter
b. resonance
c. low beam strength
d. bubble expands very little

Answer 21

Resonance

Question 22

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

a. Lowest frequency sound
b. bubble expands greatly
c. strongest harmonics
d. linear behavior

Answer 22

Linear behavior

Question 23

Where are harmonics created

Answer 23

in the tissues

Question 24

TRUE OR FALSE

Contrast harmonics created by microbubbles are much stronger than tissue harmonics

Answer 24

True

Question 25

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. Pulse inversion harmonics b. power modulation harmonics c. fill-in interpolation d. temporal compounding

Answer 25

Power modulation harmonics

Question 26

``` 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. 40dB b. 50dB c. 55dB 45dB ```

Answer 26

45dB

Question 27

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?

Answer 27

110dB

Question 28

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

Answer 28

1

Question 29

What is the primary storage device on a PACS system?

Answer 29

Hard disc drives

Question 30

Are the following procedures usually pre or postprocessing? a. Modifying a frozen image b. read zoom c. write zoom d. adjusting the brightness on the monitor e. increasing the receiver gain

Answer 30

``` Modifying a frozen image- POST read zoom- POST write zoom- PRE adjusting the brightness on the monitor--POST increasing the receiver gain--PRE ```

Question 31

Which of the following is not a form of magnetic media? a. computer memory b. video tape c. laser discs d. computer discs

Answer 31

laser discs

Question 32

What is not an advantage of paper media? a. bulky b. portability c. does not require a device to read

Answer 32

Bulky

Question 33

What is a disadvantage of optical media? a. artifacts can arise from dirt b. no standardized format from image display and storage c. can be erased by strong magnetic fields d. cannot display dynamic images

Answer 33

No standardized format from image display and storage

Question 34

Which of the following scan converters will provide the best spatial resolution? a. 256x256 pixels b. 512x512 pixels c. 128x128 pixels d. 1000x1000 pixels

Answer 34

1000x1000 pixels

Question 35

This imaging technique continues to display information from older images

Answer 35

Temporal compounding