Chapter 17 Flashcards
The incident beam is significantly altered as it passes through the patient.
a. True
b. False
True
The beam emitted from the patient contains diagnostic information.
a. True
b. False
True
Subject density refers to the impact the patient has on the resulting image receptor exposure.
a. True
b. False
True
Subject distortion occurs naturally.
a. True
b. False
True
Accurate patient positioning has very little impact upon subject distortion.
a. True
b. False
False
Shape distortion can be the result of a patient’s body habitus.
a. True
b. False
True
The patient has an impact on all the properties that affect radiographic quality.
a. True
b. False
True
The relationship between radiographic quality and the patient is termed image receptor exposure.
a. True
b. False
False
The relationship between image receptor exposure and the patient is termed subject density.
a. True
b. False
True
The relationship between radiographic contrast and the patient is termed subject contrast.
a. True
b. False
True
X-rays are attenuated
a. exponentially.
b. linearly.
c. based upon the direction of the central ray.
d. as a function of mAs.
exponentially
The ____ the body part, the ____ the attenuation.
a. more dense; less
b. thinner; greater
c. thicker; less
d. thicker; greater
thicker; greater
Which of the following elements would attenuate a greater percentage of the x-ray beam?
a. hydrogen
b. calcium
c. oxygen
d. carbon
calcium
Which of the following elements would attenuate a lesser percentage of the x-ray beam?
a. phosphorus
b. barium
c. iron
d. carbon
carbon
Attenuation is greater for elements with more ____ with which the photons may interact.
a. electrons
b. protons
c. neutrons
d. positrons
electrons
Bone produces less image receptor ____ because it attenuates the x-ray beam more than soft tissue does.
a. detail
b. contrast
c. exposure
d. distortion
exposure
For the same exposure intensity, air produces
a. less exposure intensity to the receptor than other materials.
b. greater exposure intensity to the receptor than other materials.
c. the same exposure intensity to the receptor as other materials.
d. less exposure intensity due to the high degree of photoelectric absorption.
greater exposure intensity to the receptor than other materials
Which of the following is the greatest attenuator of the x-ray beam?
a. pneumonic lung
b. pericardial fat
c. psoas muscle
d. perirenal fat
psoas muscle
Which of the following is the least attenuator of the x-ray beam?
a. aerated lung
b. pericardial fat
c. psoas muscle
d. perirenal fat
aerated lung
As subject density ____, image receptor exposure ____.
a. increases; remains the same
b. decreases; decreases
c. increases; increases
d. increases; decreases
increases; decreases
The degree of differential absorption is referred to as
a. material contrast.
b. subject contrast.
c. image receptor exposure.
d. subject density.
subject contrast
The recorded detail of a structure is dependent on
a. its position within the body.
b. the placement of the body in relationship to the film.
c. the size of the part.
d. all of the above.
all of the above
Distortion is the misrepresentation of the ____ of an object.
a. length
b. width
c. shape
d. all of the above
all of the above
The primary source of radiation exposure for occupational personnel is due to
a. Compton scatter.
b. classical scatter.
c. photoelectric effect.
d. coherent scatter.
Compton scatter
Because of its tissue composition, the human breast
a. is a high subject contrast structure.
b. yields a high contrast image.
c. is a low subject contrast structure.
d. is considered a high-attenuator of x-ray energy.
is a low subject contrast structure
With the patient in the posterior–anterior projection of the abdomen (prone),
a. renal stones would have high resolution.
b. the lumbar vertebrae would have high resolution.
c. the psoas muscles would have high resolution.
d. the anterior ribs would have high resolution.
the anterior ribs would have high resolution
All of the following refer to patient factors contributing to image quality EXCEPT
a. receptor contrast.
b. subject detail.
c. subject contrast.
d. tissue density.
receptor contrast
With the perfusion of iodinated contrast material into the kidneys,
a. a greater degree of Compton scatter is produced from the kidneys.
b. the kidneys will demonstrate lower subject contrast.
c. a greater degree of photoelectric interactions will occur in the kidneys.
d. there is less distinction between kidney structures.
a greater degree of photoelectric interactions will occur in the kidneys
All of the following are related EXCEPT
a. air.
b. barium.
c. fat.
d. bone.
barium
All of the following are true of Compton scatter EXCEPT:
a. It contributes no meaningful information the final image.
b. Its production increases as tissue density increases.
c. It is a significant contributor to occupational radiation exposure.
d. It is not a factor of exposure technique selection.
it’s production increases as tissue density increases
Clinically speaking from a diagnostic viewpoint, the only useful radiation exposure is that radiation
a. absorbed in the patient.
b. produced from Compton interactions.
c. detected by the receptor.
d. that traverses through the grid.
detected by the receptor
With a patient in the supine position, the anatomical structure that would demonstrate the greatest subject detail would be the
a. nasal bones.
b. sternum.
c. vertebral pedicles.
d. spinous processes.
spinous processes
All of the following pathological conditions would warrant an increase in exposure EXCEPT:
a. anorexia nervosa
b. osteopetrosis
c. ascites
d. bronchiectasis
anoriexia nervosa
For most additive pathologies, an increase of _ in kVp, is generally enough to compensate for the added attenuation.
a. 5%–15%
b. 20%–25%
c. 33%
d. none of the above
5%-15%
When performing a KUB on a patient with ascites, using AEC and the proper detector combination, the responsible radiographer would:
a. decrease the kVp to reduce the amount of Compton
b. take a scout image using manual techniques, to establish a back-up time for the AEC
c. allow the AEC system to adjust the exposure for the patient condition
d. immediately increase the AEC sensitivity to +2
allow the AEC system to adjust the exposure for the patient condition
