Image Analysis Chapter 1 Flashcards
How do you display torso, vertebral, cranial, shoulder, and hip images?
As if the patient were standing in an upright position
How do you display AP, PA, AP-PA oblique images of the torso, vertebrae, and cranium?
Displayed as if the viewer and patient are facing one another. the right side of the patient image is the viewers left, the left side of the patient’s image is the viewers right
How to display AP/PA (Lateral Decubitus) chest and abdomen projections
Displayed as if the viewer and the patient are facing each other. Then turned to be displayed so that the side of the patient that was positioned upward when the projection as taken is upward on the displayed image.
Which exams/projections of the upper extremity will be displayed from the finger tips?
finger, wrist, and forearm
Which exams/projections of the upper extremity will be displayed from the shoulder
elbow and humerus
Which exams of the lower extremity will be displayed from the toes?
toes, AP and AP oblique foot projections
Which exams of the lower extremity will be displayed from the hip?
lateral foot, ankle, lower leg, knee, femur
What demographic requirements must be permanently photo flashed or displayed on digital display monitor of each image?
correct patient name, age or DOB, facility name, date and time
What must be included on each image to be considered a legal document in a court of law
correct lead marker from exposure. Not post processing
Why are markers placed on the IR and not on the imaging table or patient?
This placement avoids marker distortion and magnification, preventing scatter radiation from undercutting the marker and ensures that the marker will not be projected of the IR. Prevents cross contamination
Where do you place markers for an AP/PA projection of the torso, vertebrae, or cranium?
Place R or L marker laterally on the side being marked using that patients vertebral column as a dividing plane for right and left sides
For lateral projections why are markers commonly placed anteriorly on patient and not posterior?
because markers placed posteriorly are often over exposed
For decubitus projections of the torso why is the marker placed on the “up side” or side away from the cart of table
the marker will be better visualized and less likely to obscure the VOI
When placing more than one image on same IR on a series what is the marker requirement?
Mark only one of the projections placed on the IR as long as they are all projections of the same anatomic structure
When doing bilateral exam on the same IR what is the marker requirement?
mark both projections with the correct R or L marker
How do you decide what size IR to use for a specific exam?
should be just large enough to include the required VOI and to provide a projection with the best spatial resolution
What factors dictate the orientation of the IR for specific exams?
body habitus and part length to IR system
What is the General Rule associated with the size selection and placement of IR?
long axis of the part aligned with long axis of IR
Distinguish between the different body habitus?
Hyperstenic-biggest-wide, short thorax, and broad abdomen with high diaphragm
Asthenic-smallest-long narrow thorax and abdomen with low diaphragm
Hyposthenic- bigger than asthenic but smaller than sthenic (smaller-average patient)
Sthenic- bigger than hyposthenic but smaller than hypersthenic (larger average -muscular)
When is proper collimation achieved?
When the beam of radiation is narrow enough to include only the VOI and approximately .5 inches of the required surrounding anatomy
Good collimation results in what 3 factors
- clearly delineates the VOI
- decreases the radiation dosage by limiting the amount of patient tissue exposed
- Improves the visibility of recorded details by reducing the amount of scatter radiation that reaches the IR
- Reduces histogram analysis errors
What is the general rule associated with collimation?
Each projection should demonstrate a small collimated border around the entire VOI
When does this general rule not apply?
When the ENTIRE IR must be used to prevent clipping of needed anatomy as with chest and abdomen projections