Quiz 1&2

Question 1

Which statements are true about mammography?(May be more than one answer)

a) Mammography makes use of much higher X-ray energies than conventional radiography.
b) Mammography is used on asymptomatic women.
c) Computer aided detection is a slowly emerging technology in digital mammography in the United States
d) Tomosynthesis can reduce the superimposition of anatomy above and below the in-focus plane

Answer 1

b,d

Question 2

Which of the following questions are true regarding CT imaging in the United States? (there may be more than one answer)

a) Radiation levels from medical imaging are much smaller than background radiation levels.
b) CT scanners acquire 0.5mm thick tomographic images along a 50 cm length in 5 seconds.
c) The use of ferrous contrast injected is common and allows functional assessment of various organs.
d) More than 60 million CT scans are being performed annually.

Answer 2

b,d

Question 3

Which of the following are true regarding magnetic resonance imaging? (There may be more than one answer)

a) 1.5 T is a common field strength
b) 64 MHz is a common resonance frequency
c) The acquisition of the highest quality MR scans requires a longer time than CT scans.
d) MRI can be used to detect the presence of motion, which is useful to assess blood flow.

Answer 3

a,b,c,d

Question 4

Which of the following statements are true regarding nuclear medicine imaging? (there may be more than one answer)
a)The thyroid is a particularly difficult organ to image using nuclear medicine techniques

b) SPECT imaging uses projection images from a series of different angles, coupled with computerized reconstruction to form an image.
c) PET is acronym for Proton Emission Tomography
d) PET and CT imaging is often combined to yield both anatomical and physiological information.

Answer 4

b,d

Question 5

The limiting spatial resolution of fluoroscopy is 0.125cm. (True or False)

Answer 5

False

Question 6

X-rays are electromagnetic radiation produced within the nucleus. (True or False)

Answer 6

False

Question 7

Planks constant is 6.626 x 10^(-34)J-s. (True or False)

Answer 7

True

Question 8

The average energy expended per ion pair (W) in water is about 30 keV. ( True or False)

Answer 8

False

Question 9

The L shell in an atom can hold up to 10 orbital electrons. ( True or False)

Answer 9

False

Question 10

An x-ray from a K-L shell transition in Tungsten will have an energy of 58.5 keV. ( True or False)

Answer 10

True

Question 11

Ultrasound is a form of electromagnetic radiation. (True or False)

Answer 11

False

Question 12

Ultrasound represents the frequency above 20kHz. ( True or False)

Answer 12

True

Question 13

The average speed of sound in soft tissue is 1450 m/s. ( True or False)

Answer 13

False

Question 14

A high frequency ultrasound image provides better spatial resolution than a low frequency image ( True or False)

Answer 14

True

Question 15

If a 400 mW US pulse loses 10dB of intensity, then its remaining intensity is?

Answer 15

40 mW

Question 16

The acoustic impedance of the kidney is greater than that of fat. ( True or False)

Answer 16

True

Question 17

A good rule of thumb for US attenuation in tissue is that it loses 0.5 dB/cm/MHz. ( True or False)

Answer 17

True

Question 18

There are two sets of piezoelectric crystals in an US transducer, one to act as a transmitter and one to act as a receiver. ( True or False)

Answer 18

False

Question 19

A linear US transducer array typically contains up to 512 elements. ( True or False)

Answer 19

True