Physics Chapter 15 - 17

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:

Answer 2

image fade

Question 3

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

Answer 3

True.

Question 4

The 2 important elements of digital scan converters are:

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 ______.

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

Answer 8

preprocessing

Question 9

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

Answer 9

NO

Question 10

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

Answer 10

coded excitation

Question 11

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

Answer 11

dynamic range

Question 12

PACS stands for

Answer 12

Picture Archiving and Communications System

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

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

Answer 15

edge enhancement

Question 16

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

Answer 16

False

Question 17

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

Answer 17

8 MHz

Question 18

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

Answer 18

deeper

Question 19

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

Answer 19

False

Question 20

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

Answer 20

large enough to pass through the capillaries

Question 21

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

Answer 21

resonance

Question 22

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

Answer 22

linear behavior

Question 23

Where are harmonics created

Answer 23

in the tissues

Question 24

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

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

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?

Answer 26

45 dB

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

110 dB

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-------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

Answer 30

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

Question 31

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

Answer 31

laser discs

Question 32

What is not an advantage of paper media?

Answer 32

bulky

Question 33

What is a disadvantage of optical media?

Answer 33

no standardized format from image display and storage

Question 34

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

Answer 34

1000 X1000 pixels

Question 35

This imaging technique continues to display information from older images.

Answer 35

temporal compounding