Positioning 1- Chapter 1 Flashcards
What are the four types of image receptors?
- Cassette with film
- photostimulable storage phosphor image plate(PSP IP)
- solid-state digital detectors
- Portable digital radiography
- Fluoroscopic image receptor
What is DR or DDR?
Direct digital radiography
Digital radiography
What is CR?
Computed Radiography
What is special resolution and what is it controlled by?
•ability to visualize small structures Previously termed recorded detail Controlled by •IP phosphor (digital) •DEL size (digital) •Geometry •Distance •Focal spot size •Motion •Film •Intensifying screen
What is distortion and what is it controlled by?
Misrepresentation of the size or shape of a structure
Shape distortion, elongation or foreshortening, controlled by
•Alignment
•Central Ray
•Anatomic part
•Image receptor (IR)
•Angulation
Magnification is size distortion Present in all images Controlled by •Object-image receptor distance (OID) Generally as close as possible •Source-image receptor distance (SID) Generally 40" or 72"
What are the three types of motion?
- involuntary
- voluntary
- equipment
Which of the quality factors is defined as the overall blackness (or brightness, in digital) of an image?
A. Contrast
B. Density
C. Distortion
D. Spatial resolution
B. Density
Which image quality factor allows the distinction between adjacent structures and tissues?
A. Contrast resolution
B. Brightness
C. Distortion
D. Special resolution
A. Contrast resolution
For lateral projections of the head and trunk (head,spine,chest, abdomen, and pelvis) where do you place markers?
Always mark the side closest rival to IR. If the left side is closest, use the L marker. The marker is typically placed anterior to the anatomy.
For oblique projections that include R and L sides of the body (spine, chest, and abdomen), where is marker placed?
The ide down, or nearest IR, is typically marked. For a right posterior oblique (RPO) position, mark R side
For limb projections, what markers should be used?
Use appropriate R or L marker. The marker must be placed within the edge of the collimating x-Ray beam.
All of the following are examples of involuntary motion, except:
A. Peristalsis
B. Heartbeat
C. Breathing
D. Chills
C. Breathing
How do radiographer a help reduce the risk of imaging involuntary motion?
A. Use immobilization
B. Appropriate patient instructions
C. Clear Communications
D. Use the shortest possible exposure time
D. Use the shortest possible exposure time
All of the following are required ID on a radiographic image, except the:
A. Side marker
B. Patient name or ID number
C. Referring physician’s name
D. Name of the facility
C. Referring physician’s name
What are the common distances used in SID?
40 inches (102cm) traditionally used on most exams
72 inches(183cm) used on exams with increased OID to reduce magnification
48 inches (122cm) is recent increase in many facilities
How many cm is 40 inches?
102cm
How many cm is 48 inches?
122 cm
How many cm is 72 inches?
183 cm
How many inches is 102 cm
40 inches
How many inches is 122 cm
48 inches
How many inches is 183 cm?
72 inches
A technique chart must include all of the following, except
A. Pathology type
B. kVp
C. AEC
D. Grid
A. Pathology type
Which guideline is used to local the pubic symphysis on an obese patient who is approximately 5 feet, 5 inches?
A. 15 inches from jugular notch
B. 21 inches from the jugular notch
C. 22 inches from the jugular notch
D. 24 inches from the jugular notch
C. 22 inches from the jugular notch
How do you find the pubic symphysis on an obese patient?
• Locate the jugular notch
pubic symphysis can be located by using these measurements from the jugular notch.
• 6 feet: 24 inches
WHAT IS AN IMAGE RECEPTOR?
The device that receives the energy of the x-ray beam and forms the image of the body part
Define Optical Density (OD)
Optical density is defined as the degree of blackening when associated with radiographic film and as brightness when appearance on a digital display is described.
Define brightness
Balance of light and dark shades in a displayed image
Define contrast
Contrast is the relative difference of intensities in two adjacent regions of an image.
Define special resolution
The ability to visualize small structures
Define magnification
Enlargement of an area.
Increases with increased OID and decreased SID
Define optical density(OD)
Degree of blackening(film)
Brightness(digital)
Define brightness
Digital imaging term equivalent to OD
Define contrast
The difference in density of any two areas on an image
Define spatial resolution
The ability to visualize small structures
Define distortion
The misrepresentation of the size or shape of any anatomic structure
Define magnification
A type of distortion in which the image is larger than the actual object (magnification is present in every image)
Increases with increased OID
And decreased SID
Define contrast resolution
Contrast resolution applies to digital imaging systems and is primarily controlled by bit depth, the number of brightness values possible for each pixel
From the following list, what are the factors that mAs affect in digital imaging
A. OD B. Contrast C. Image noise D. Spatial resolution E. Patient dose
A. OD
C. Image noise
E. Patient dose
What exposure factor controls radiographic contrast?
Kilovolt peak(kVp)
What six factors control spa tail resolution?
A. IP phosphor(digital) B. Flat panel detector C. Motion D. Distance E. Exposure F. Geometry G. Focal spot size H. mA I. kVp
A,b,c,d,f,g
What two factors control radiographic magnification?
A. Time, in seconds
B. mA
C. kVp
D. Object-to-image-receptor distance(OID)
E. Source-to-image-receptor distance(SID)
D. OID
E. SID
True or false. All radiographs yield some degree of magnification
True
Which five factors control or affect shape distortion of a body part
A. Alignment B. Angulation C. Central Ray D. IR E. Anatomic part F. OID G. SID
A B C D E
Define and describe the anatomic position
Refers to a position in which the patient is standing erect with the face and eyes directed forward, arms extended by the sides with the palms of the hands facing forward, heels together, and toes pointing anteriorly
Describe how a posteroanterior (PA) projection radiograph of the chest should be displayed on a viewing device
As though the patient were standing in the anatomic position face to face with the viewer
Describe how lateral projection radiographs should be displayed
As though the viewer sees the patient from the perspective of the X-ray tube ( display the image so that the side of the patient closer to the IR during the procedure is also the side of the image closer to the viewbox)
Describe how hand and foot radiographs should be displayed
With the digits pointing upward and as viewed from the perspective of the X-ray tube
Describe the two most common ways that lateral decubitus radiographs are displayed
- With the patient in the anatomic position
2. In the manner in which the IR was positioned when the exposure was made
When the radiologist is unable to see the patient, who is responsible for ensuring that an adequate clinical history accompanies the radiograph?
The radiographer
What is the easiest and most convenient method to prevent the spread of microorganisms?
Washing the hands
According to the centers for disease control and prevention, all human blood and certain bodily fluids should be treated as if they contain…
Pathogenic microorganisms
What protective apparel should radiographers wear if the possibility of touching blood exists?
Gloves
What procedure should be followed to dispose of used hypodermic needles properly?
Place them in a puncture-proof container
Define disinfectant
A chemical substance that kills pathogenic bacteria
Define antiseptic
A chemical substance that inhibits the growth of pathogenic microorganisms without necessarily killing them
Define sterilization
Destruction of all microorganisms
Define disinfection
Process of killing only pathogenic microorganisms
Which term classifies isopropyl alcohol?
A. Antiseptic
B. Disinfectant
A. Antiseptic
What information should be included in a procedures(or protocol) book that identifies each examination performed in the radiography department?
An outline of each procedure, the number of staff required, duties of each member of the team, and a listing of the required sterile and nonsterile items
List the three ways a patient’s colon may be cleansed for an abdominal examination
Limited diet
Laxatives,
and enemas
Identify the three types of muscular tissue and state the type of motion(voluntary or involuntary) associated with each
Smooth- involuntary(peristalsis)
Cardiac- involuntary(systole)
Striated-voluntary
The rhythmic motion of smooth muscle structures is called…
Peristalsis
What exposure factor is used to control involuntary motion?
Exposure time
What body system controls the movement of voluntary muscles ?
central nervous system(CNS)
Four ways voluntary motion can be controlled by a radiographer
A. Increased mAs B. Decrease mAs C. Apply immobilization D. Give clear instructions E. Adjust support devices F. Increase exposure time G. Decrease exposure time H. Provide patient comfort
C
D
E
G
Why is it necessary to ensure that any folds in cloth gowns are straightened out before making the radiographic exposure?
To prevent confusing shadows
What device must be removed from the patient within the area of interest when the skull is examined?
Dentures Removable bridgework Earrings Necklaces Hairpins Eyeglasses
Before beginning a radiographic examination, what should the radiographer do to gain the cooperation of a coherent patient?
Give an explanation of the procedure to be performed
What is the minimum number of personnel that should be used to transfer a helpless patient from a gurney to the radiographic table?
Four
What four items of identification information that should be on every radiograph?
A. Patient's name B. Patient's diagnosis C. Date of examination D. Institutional identity E. Patient's marital status F. Side marker (right or left) G. Requesting physician's name
A
C
D
F
Some examinations require an additional marker to indicate the
__________________ after an introduction of a contrast medium
Cumulative time
Indicate which of the following is not recommended or unacceptable for right and left side marker placement
A. Use of electronic insertion of the side marker in digital imaging
B. Placement of the marker in the anatomy of interest
C. Placement of the marker on the border of the collimated field
D. Writing the side marker on hard copy images
A
B
D
What adjustment can be made by the radiographer to compensate for an increase in OID?
Increase the SID
List four reasons why it would become necessary to angle the central Ray
To avoid superimposition of overlaying or underlying structures
To avoid superimposing a curved structure on itself
To project through angled joints
To project through angled structures without foreshortening or elongation
List two purposes of collimation when restricted to irradiate only the anatomy of interest
- it minimizes the amount of radiation to the patient by restricting exposure to essential anatomy only
- it reduces the amount of scatter radiation that can reach the IR, which reduces the potential for a reduction in contrast resolution
When using film/screen cassettes or computed radiography imaging plates, how is the field size limited to prevent overexposing the patient?
The field size is limited to prevent overexposing the patient by adjusting the collimation to the same anatomic area size or smaller when using either a cassette or an IP
True or false. In a direct digital image, the field size or collimation must be manually adjusted.
True
True or false. Creating an image using a larger than required (necessary) field size is a violation of the ASRT code of ethics.
True
True or false. Shuttering of direct digital images is an acceptable substitution for proper collimation.
False. Shuttering gives only the displayed image the appearance of proper collimation and does not protect the patient from unnecessary radiation exposure. The use of shuttering in place of proper collimation is a violation of the ASRT code of ethics.
List the three guidelines for determining when gonadal shielding should be used.
When the gonads are in close proximity to the primary x-ray field (about 5cm), when the clinical objective of the examination is not compromised, and when the patient has a reasonable reproductive potential.
Which patient conditions require a decrease in radiation?
Old age Atrophy Emaciation Emphysema Pneumothorax Degenerative arthritis
Which patient conditions require an increase in radiation exposure?
Ascites Edema Pneumonia Enlarged heart Hydrocephalus Pleural effusion
What are the two phases of respiration?
Inspiration(Inhalation)
Expiration(exhalation)
What respiration phase is requested when the goal is to expand lung fields to the maximum extent possible?
Inspiration
What respiration procedure provides for lung motion but not rib motion?
Slow, deep breathing
What is AP?
Anteroposterior
What is AEC?
Automatic exposure control
What is ASRT?
American Society of Radiographic Technologists
What is IR?
Image receptor
What is CR(imaging method)?
Computed Radiography
What is CR(x-ray beam reference)?
Central Ray
What is mAs?
Milliampere-second
What is DR?
Digital radiography
Which body parts are most affected, in terms of increased size, by morbid obesity?
Thorax, stomach, and colon
What bony landmark(s) are usually palpable on obese patients?
A. Jugular notch
B. Xiphoid process
C. ASIS
D. Iliac crest
A. Jugular notch
What is the approximate distance of the pubic symphysis from the jugular notch on a patient who measures 5 feet, 3 inches (160 cm) in height?
22 inches
