Quiz 2 Flashcards
is a term that is used to indicate the patient’s general physical position, such as supine, prone, recumbent, or erect.
Position
is used to describe specific body positions by the body part closest to the IR, such as lateral and oblique.
Position
• The term position should be
“restricted to discussion of the patient’s physical position.”
is a correct positioning term that describes or refers to the path or direction of the central ray (CR), projecting an image onto an image receptor (IR).
Projection
• The term projection should be
“restricted to discussion of the path of the central ray.
Describes the body part as seen by the IR or other recording medium, such as a fluoroscopic screen.
View
• In the United States, the term view should be
“restricted to discussion of a radiograph or image.”
Evaluation Criteria Format
- Anatomy demonstrated
- Position
- Exposure
Two types of markers:
Patient Identification
Anatomic side markers
Markers that are used for special comparison PA projections of the chest.
Inspiration (INSP) and expiration (EXP) markers
Markers that can be used for rotation projections, such as for the proximal humerus and shoulder.
Internal (INT) and external (EXT) markers
are defined as projections commonly taken on patients who can cooperate fully.
Routine projections
These are defined as projections most commonly taken to demonstrate better specific anatomic parts or certain pathologic conditions or projections that may be necessary for patients who cannot cooperate fully.
Special Projections
Three reasons for this general rule of a minimum of two projections are as follows:
- Superimposition of anatomic structures
- Localization of lesions or foreign bodies
- Determination of alignment of fractures
refers to the process of applying light pressure with the fingertips directly on the patient to locate positioning landmarks.
Palpation
is the distance from the anode focal spot inside the x-ray tube to the IR.
Source–to–image receptor distance (SID)
Directly affects magnification of the anatomy on the image, the spatial resolution, and the dose to the patient.
SID
The distance between the focal spot of the radiography tube and the skin of the patient is termed the
source–to–skin distance (SSD).
The beam of radiation must be restricted to irradiate only the anatomy of interest.
This restriction of the x-ray beam is called
collimation
The three types of muscular tissue that affect motion are the following:
- Smooth(involuntary)
- Cardiac (involuntary)
- Striated (voluntary)
The rhythmic action of the muscular tissue of the alimentary tract, called _____, is normally more active in the stomach (about three or four waves per minute) and gradually diminishes along the intestine.
peristalsis
are composed of striated muscular tissue and are controlled by the central nervous system.
voluntary, or skeletal, muscles
A thin radiolucent mattress, called a ____, may be placed on the radiographic table to reduce movement related to patient discomfort caused by lying on the hard surface.
table pad
This device is used to measure the thick- ness of body parts to ensure that accurate and consistent exposure factors are used.
Caliper
is essential when radiosensitive organs, such as the thyroid gland, breasts, and gonads, are in or near the useful beam and the use of such shielding does not interfere with the objectives of the examination.
Specific area shielding
The most common and most important area shielding is ____, which significantly lowers the dose to the reproductive organs.
gonadal shielding
, which are attached to the collimator, are placed between the x-ray tube and the patient and cast a shadow on the patient when the collimator light is turned on.
Shadow shields
are used most commonly for patients in recumbent positions.
Flat gonadal contact shields
are placed over the gonadal area to attenuate scatter or leakage radiation or both.
Vinyl-covered lead shields
The radiographer can control voluntary patient motion on images by doing the following:
- Givingclearinstructions
- Providing patient comfort
- Adjusting support devices
- Applying immobilization
Two types of shield
Shadow & Contact Shield
This restriction of the x-ray beam, called collimation, serves two purposes.
- Minimizes the amount of radiation to the patient by
restricting exposure to essential anatomy only. - Reduces the amount of scatter radiation that can reach the IR, which reduces the potential for a reduction in
contrast resolution.
