Image Quality Factors
Image contrast is defined as the visible difference in
brightness between two areas in the image
which part of the humerus articulates with the ulna to form the elbow joint?
trochlea
The appearance of quantum mottle on a radiographic is caused by
inadequate receptor exposure
DICOM PS3.14 is a standard that controls the
look-up table (LUT) of the monitor display
Gray-scale is defined as
the total brightness levels that are visible in an image
During a radio graphic imaging of the chest, subject contrast is most likely to be increased with which pathological condition?
pneumothorax
A patient is to be scheduled for a barium enema (BE), an abdominal sonogram (US), and an upper GI (UGI). The proper sequence for performing these procedures is?
US, BE, UGI
Incomplete erasure of a CR image receptor may produce an artifact called
ghost image
“Coincidence testing” of the x-ray tube assembly is an evaluation of
light field accuracy
Which structure forms the anterior border of the pelvic inlet?
Pubic symphysis
Which of the following anatomical parts can be an indicator of the spatial resolution recorded in a radiographic image?
trabecular bone
the esophagus originates
at the inferior border of the cricoid cartilage (C6)
When reviewing the radiographic exposure indicators and deviation, what does an “S” (sensitivity) number significantly below 200 indicate?
excessive receptor exposure
Actual exposure time must be within what percentage of indicated exposure time?
+- 5%
What degree of rotation is used for a lateral projection of the scapula?
45-60 degrees
What happens to photons as the distance from the source increases?
photons diverge and become less intense
A patient with a hypersthenic body habitus requires a lateral thoracic spine radiograph, but standard technical factors result in inadequate penetration with appropriate exposure levels. What procedural adaptation can improve image quality while maintaining exposure?
increase kVp and adjust mAs accordingly
Physical damage to the structure of a CR image receptor is likely to manifest on a radiographic histogram as
hyperdense artifact
The mGy/mAs measurement between adjacent mA stations should not vary by more than
+- 10%
For an AP axial projection of the urinary bladder during a cystogram, what is the typical central ray angulation?
10-15 degrees caudad
Which part of the x-ray beam has different signal intensities that correspond to the anatomy represented on the image receptor?
remnant beam
in an upright abdomen radiograph, how can the radiographer ensure that the entire diaphragm is included in the image?
place the top of the image receptor at the level of the axilla
What is used to create the patients requisition?
Electronic Medical Record (EMR)
Routine image receptor calibration ensures that the image receptor maintains an accurate and reliable
exposure response
which of the following is one reason iodine is used as a contrast medium in radiography?
K-shell binding energy