Test Bank for Digital Radiography and PACS,
4th - 2023 All Chapters
Approximately _______% of the x-ray beam incident on the
patient is transmitted through the patient without interaction to
become part of the image-forming beam. - ANSWER ✔️ 1
The kinetic energy of photoelectrons in the image intensifier is
greatly increased by the _____________________. - ANSWER
✔️ potential difference across the tube
Beam restriction with a(n) ____________ is only accurate at a
fixed SID. - ANSWER ✔️ aperture diaphragm
Compton scatter contributes to _____________.
a.useful information
b.image noise
c.useful information, image noise and image contrast
d.image contrast - ANSWER ✔️ image noise
Decreasing the kVp will increase ___________.
a.Compton scatter
b.patient dose
c.optical density
d.image noise - ANSWER ✔️ patient dose
Contrast resolution is improved by _____________.
a.tight collimation, lowering kVp and patient compression
b.patient compression
,c.lowering kVp
d.tight collimation - ANSWER ✔️ tight collimation, lowering kVp
and patient compression
What is the typical number of projections in DRT?
a.41 to 60
b.10 to 25
c.1 to 9
d.26 to 40 - ANSWER ✔️ 10 to 25
How can you improve image contrast with a heavy patient without
increasing patient dose?
a.Use tight collimation.
b.Raise kVp and lower mAs.
c.lower kVp and raise mAs and use tight collimation
d.Lower kVp and raise mAs. - ANSWER ✔️ a.Use tight
collimation.
Lowering kVp ________ patient dose and _________ image
contrast.
a.lowers; increases
b.lowers; decreases
c.increases; increases
d.increases; decreases - ANSWER ✔️ increases; increases
A grid is constructed with 40-μm strips and a 250-μm interspace.
What percentage of x-rays incident on the grid will be absorbed
by its entrance surface?
a.
,12.5%
b.
11.5%
c.
14%
d.
10% - ANSWER ✔️ 14
A grid is fabricated of 25-μm lead grid strips sandwiched between
interspace material that is 300-μm thick. The height of the grid is
1.2 mm. What is the grid ratio?
a.
8:1
b.
16:1
c.
12:1
d.
4:1 - ANSWER ✔️ 4:1
An aluminum step wedge is placed on a tissue phantom that is 20
cm thick and a radiograph is made. Without a grid, analysis of the
radiograph shows a 1.7% contrast. With a 8:1 grid, radiographic
contrast is 2.4%. What is the contrast improvement factor of this
grid?
a.
2.6
b.
, 1.9
c.
1.4
d.
2 - ANSWER ✔️ 1.4
What is the brightness gain for a 17-cm image-intensifier tube
with a flux gain of 100 and a 2.5-cm output phosphor?
a.
4,000
b.
3,654
c.
4,624
d.
5,000 - ANSWER ✔️ 4624
It is a safe practice to keep CR cassettes in a "radiation safe"
area of an x-ray suite during exams.
Select one:
True
False - ANSWER ✔️ False
Filtered back projection in DRT refers to ___________________.
a.spatial resolution
b.image reconstruction
c.prepatient collimation
d.beam filtration - ANSWER ✔️ b.
image reconstruction
4th - 2023 All Chapters
Approximately _______% of the x-ray beam incident on the
patient is transmitted through the patient without interaction to
become part of the image-forming beam. - ANSWER ✔️ 1
The kinetic energy of photoelectrons in the image intensifier is
greatly increased by the _____________________. - ANSWER
✔️ potential difference across the tube
Beam restriction with a(n) ____________ is only accurate at a
fixed SID. - ANSWER ✔️ aperture diaphragm
Compton scatter contributes to _____________.
a.useful information
b.image noise
c.useful information, image noise and image contrast
d.image contrast - ANSWER ✔️ image noise
Decreasing the kVp will increase ___________.
a.Compton scatter
b.patient dose
c.optical density
d.image noise - ANSWER ✔️ patient dose
Contrast resolution is improved by _____________.
a.tight collimation, lowering kVp and patient compression
b.patient compression
,c.lowering kVp
d.tight collimation - ANSWER ✔️ tight collimation, lowering kVp
and patient compression
What is the typical number of projections in DRT?
a.41 to 60
b.10 to 25
c.1 to 9
d.26 to 40 - ANSWER ✔️ 10 to 25
How can you improve image contrast with a heavy patient without
increasing patient dose?
a.Use tight collimation.
b.Raise kVp and lower mAs.
c.lower kVp and raise mAs and use tight collimation
d.Lower kVp and raise mAs. - ANSWER ✔️ a.Use tight
collimation.
Lowering kVp ________ patient dose and _________ image
contrast.
a.lowers; increases
b.lowers; decreases
c.increases; increases
d.increases; decreases - ANSWER ✔️ increases; increases
A grid is constructed with 40-μm strips and a 250-μm interspace.
What percentage of x-rays incident on the grid will be absorbed
by its entrance surface?
a.
,12.5%
b.
11.5%
c.
14%
d.
10% - ANSWER ✔️ 14
A grid is fabricated of 25-μm lead grid strips sandwiched between
interspace material that is 300-μm thick. The height of the grid is
1.2 mm. What is the grid ratio?
a.
8:1
b.
16:1
c.
12:1
d.
4:1 - ANSWER ✔️ 4:1
An aluminum step wedge is placed on a tissue phantom that is 20
cm thick and a radiograph is made. Without a grid, analysis of the
radiograph shows a 1.7% contrast. With a 8:1 grid, radiographic
contrast is 2.4%. What is the contrast improvement factor of this
grid?
a.
2.6
b.
, 1.9
c.
1.4
d.
2 - ANSWER ✔️ 1.4
What is the brightness gain for a 17-cm image-intensifier tube
with a flux gain of 100 and a 2.5-cm output phosphor?
a.
4,000
b.
3,654
c.
4,624
d.
5,000 - ANSWER ✔️ 4624
It is a safe practice to keep CR cassettes in a "radiation safe"
area of an x-ray suite during exams.
Select one:
True
False - ANSWER ✔️ False
Filtered back projection in DRT refers to ___________________.
a.spatial resolution
b.image reconstruction
c.prepatient collimation
d.beam filtration - ANSWER ✔️ b.
image reconstruction
