RTBC IMAGE EVALUATION AND QUALITY
CONTROL 140 QUESTIONS & CORRECT ANSWERS
Receptor exposure is defined as the:
Amount of radiation striking the image receptor
Which technical factor should the technologist use to control the receptor
exposure?
Milliamperage-seconds (mAs)
An under-exposed image might have an image artifact called:
Mottle
A technologist can identify an image produced with excessively high milliampere-
seconds (mAs) based on which of the following?
An exposure indicator outside of the acceptable range
Changes to the milliamperage (mA), or exposure time, are known to affect what
aspect of the x-ray beam?
Intensity
A radiograph of the forearm is acquired using 2.5 milliamperage (mA) at 60
kilovoltage peak (kVp). What new kVp would be required to double the exposure?
69 kVp
An increase in tube potential would increase receptor exposure by increasing
which two of the following? Select two)
- Penetrating ability of the beam
- Number of photons in the beam
What error is demonstrated in the following image?
Quantum mottle
,A radiograph is produced using 4 milliampere-seconds (mAs) and 70 kilovoltage
peak (kVp). The resulting receptor exposure is 0.001 milligray (mGy). If technical
factors are changed to 8 mAs and the same kVp, the nect radiograph will have a
receptor exposure of:
0.002 mGy
How often should technologists check the exposure indicators and deviation
index on a radiograph?
After each exposure
Assuming all other factors remain constant, what field size will produce the
lowest receptor exposure?
8 in x 10 in
Failing to adjust the exposure factors when imaging a patient with severe
osteoporosis could have what effect on receptor exposure?
Increased receptor exposure
A new x-ray machine is installed in the department with 3.0 mm of aluminum (Al)
filtration. Increasing the filtration to 3.5 mm would result in which two of the
following? (Select two)
- Decreased receptor exposure
- Decreased patient skin dose
A portable chest x-ray is required on a very small patient. The milliampere-
seconds (mAs) and kilovoltage peak (kVp) are set as low as possible, but the
technologist still expects the receptor exposure to be too high. How can the
technologist decrease receptor exposure?
Increase the source-to-image distance (SID)
An anteroposterior (AP) chest x-ray was obtained at 40 inches (102 cm), 14" x 17"
collimation, 2.5 mm aluminum (Al) filtration, and with a 12:1 grid. Which variable
change would increase receptor exposure?
Decreased grid ratio
What effect does receptor exposure have on image quality?
, Underexposure results in quantum mottle
The law that governs the effect of source-to-image distance (SID) on receptor
exposure is known as:
Inverse square law
Which of the following is a form of image noise that results from underexposure?
Mottle
Receptor exposure is affected by which three of the following? (Select three)
- Generators
- Collimation
- Filtration
Which three of the following variables that affect receptor exposure can be
controlled by the x-ray operator? (Select three)
- Filtration
- Grid ratio
- Source-to-image distance (SID)
Spatial resolution in digital radiography is defined as the:
Structural sharpness recorded in the radiograph
An image with high spatial resolution can also be described as having:
High sharpness
How does decreased image contrast affect the structural sharpness of a
radiograph?
Decreased visibility of structural sharpness
Which of the following images demonstrates the lowest spatial resolution?
Image (B)
The spatial resolution of a radiographic system is measured with units of:
Line-pairs per millimeter (lp/mm)
CONTROL 140 QUESTIONS & CORRECT ANSWERS
Receptor exposure is defined as the:
Amount of radiation striking the image receptor
Which technical factor should the technologist use to control the receptor
exposure?
Milliamperage-seconds (mAs)
An under-exposed image might have an image artifact called:
Mottle
A technologist can identify an image produced with excessively high milliampere-
seconds (mAs) based on which of the following?
An exposure indicator outside of the acceptable range
Changes to the milliamperage (mA), or exposure time, are known to affect what
aspect of the x-ray beam?
Intensity
A radiograph of the forearm is acquired using 2.5 milliamperage (mA) at 60
kilovoltage peak (kVp). What new kVp would be required to double the exposure?
69 kVp
An increase in tube potential would increase receptor exposure by increasing
which two of the following? Select two)
- Penetrating ability of the beam
- Number of photons in the beam
What error is demonstrated in the following image?
Quantum mottle
,A radiograph is produced using 4 milliampere-seconds (mAs) and 70 kilovoltage
peak (kVp). The resulting receptor exposure is 0.001 milligray (mGy). If technical
factors are changed to 8 mAs and the same kVp, the nect radiograph will have a
receptor exposure of:
0.002 mGy
How often should technologists check the exposure indicators and deviation
index on a radiograph?
After each exposure
Assuming all other factors remain constant, what field size will produce the
lowest receptor exposure?
8 in x 10 in
Failing to adjust the exposure factors when imaging a patient with severe
osteoporosis could have what effect on receptor exposure?
Increased receptor exposure
A new x-ray machine is installed in the department with 3.0 mm of aluminum (Al)
filtration. Increasing the filtration to 3.5 mm would result in which two of the
following? (Select two)
- Decreased receptor exposure
- Decreased patient skin dose
A portable chest x-ray is required on a very small patient. The milliampere-
seconds (mAs) and kilovoltage peak (kVp) are set as low as possible, but the
technologist still expects the receptor exposure to be too high. How can the
technologist decrease receptor exposure?
Increase the source-to-image distance (SID)
An anteroposterior (AP) chest x-ray was obtained at 40 inches (102 cm), 14" x 17"
collimation, 2.5 mm aluminum (Al) filtration, and with a 12:1 grid. Which variable
change would increase receptor exposure?
Decreased grid ratio
What effect does receptor exposure have on image quality?
, Underexposure results in quantum mottle
The law that governs the effect of source-to-image distance (SID) on receptor
exposure is known as:
Inverse square law
Which of the following is a form of image noise that results from underexposure?
Mottle
Receptor exposure is affected by which three of the following? (Select three)
- Generators
- Collimation
- Filtration
Which three of the following variables that affect receptor exposure can be
controlled by the x-ray operator? (Select three)
- Filtration
- Grid ratio
- Source-to-image distance (SID)
Spatial resolution in digital radiography is defined as the:
Structural sharpness recorded in the radiograph
An image with high spatial resolution can also be described as having:
High sharpness
How does decreased image contrast affect the structural sharpness of a
radiograph?
Decreased visibility of structural sharpness
Which of the following images demonstrates the lowest spatial resolution?
Image (B)
The spatial resolution of a radiographic system is measured with units of:
Line-pairs per millimeter (lp/mm)
