This course introduces the beginning radiography student to the following: organization of medical centers/hospitals, diagnostic imaging departments and the radiography program. Areas of study include: policies, protocols and administrative procedures of the College and program, information regarding health and safety procedures within the clinical area, radiation protection, x-ray production, image formation, patient care guidelines, professional organizations, critical thinking and problem solving strategies, professional ethics and medical law and human diversity.
Prerequisite: Admission into Radiography Program
Powerpoint - Chapter 1
Cardiovascular Interventional Imaging:
•Uses x-rays to visualize human blood vessels and heart anatomy
•Requires the use of a catheter and the injection of x-ray contrast material to visualize anatomy
•Uses very–high-energy ionizing radiation to treat malignant tumors (cancer)
Health Care Team:
Chapter 1 - Merrills V-1 - Preliminary Steps in Radiography
Ethics on Radiologic Technology
- Ethics - A health professional's moral responsibilities.
- The science of appropriate conduct towards others
- honesty and integrity to promote the welfare of the patient are of the utmost importance
American Society of Radiologic Technologists (ASRT) Code of Ethics
- Read p. 2
1. Professional Conduct
2. Advance of the Profession
4. Utilization of Learned Knowledge
7. Equipment Operations and Radiation Protection
8. Ethical Conduct
9. Privacy and Confidentiality
10. Continuing Education
Image Receptor (IR)
- Device that receives the energy of the x-ray beam and forms the latent image.
Latent Image: invisible image on IR before processing
Manifest Image: visible image - post processing
1. Screen Film Cassette - wet processing
2. Image Plate (IP) - used in computed radiography - laser processing
3. Direct Radiography (DR) - flat panel built into equipment- image sent directly to computer
4. Fluoroscopic Screen - image transmitted to a television - allows for real time viewing
Definition - an image produced using ionizing radiation
Radiography is performed by radiographers (also referred to as radiologic technologists).
Radiography - the practice of producing radiographs for diagnostic purposes.
Radiographer - an allied health professional who performs diagnostic examinations on patients using a
variety of imaging modalities. The technical duties of a radiographer include:
- evaluating radiographs
- evaluating/monitoring equipment performance
- patient assessment and education
Initial analysis of a radiograph :
1. Realization of superimposition of anatomical structures
2. Adjacent structure recognition
3. correct optical density on film - overall blackening of the film
4. correct level of radiographic contrast demonstrated - differences in density allowing for
anatomical structure differentiation
5. Visualization of recorded detail - degree of geometric sharpness of anatomical structures
6. Magnification of anatomical structures - generally in radiography, magnification of structures
7. Recognition of shape distortion - misrepresentation of the size or shape of the anatomical
Density is primarily controlled by the milliamperage seconds ( mAs ) used to create the image.
Contrast is primarily controlled by the kilovoltage used to create the image.
Low contrast = image which is more gray (many shades of gray)
High contrast = image which is more black/white (fewer shades of gray)
Three factors affect the x-ray emission from the tube. These factors are controlled by the radiographer.
2. kilovoltage (kVp)
Density and contrast are known as the photographic properties of the film.
Recorded detail and distortion are known as the geometric properties of the film.
Magnification of anatomical structures is reduced when the anatomical part is placed as close as possible to the IR (minimal OID - object to image distance) and the tube is placed at a sufficient distance from the IR
(using an increased/standardized SID - source to image receptor distance).
Display of Radiographs
- radiologist preference as to how he/she places films on the viewing device (also called a viewbox or
Radiographs are usually placed on the illuminator and oriented so that the individual looking at the radiograph sees the body part placed in the anatomical position.
- the patient's left side is on the viewer's right side and vice versa
Anatomic Position - a conventional position of the body, as if standing erect, facing directly forward,
feet pointed forward slightly apart, arms hanging down at sides with the palms facing
forward. This is the standard neutral position of reference used to describe sites or
motions of various parts of the body.
Radiographic Projection - the path of travel of the x-ray beam through the patient before striking the film.
PA - Posteroanterior Projection - beam enters patient's posterior aspect and exits the anterior aspect
AP - Anteroposterior Projection - beam enters the patient's anterior aspect and exits the posterior aspect
- hand and wrist radiographs are positioned on the illuminator so that the digits (fingers) point towards the
- toe and foot radiographs are displayed on the illuminator with the toes pointing towards the ceiling.
Toe, foot, hand and wrist radiographs are displayed on the illuminator as though the individual looking at the radiograph is in the position of the x-ray tube.
Lateral Projection - patient's right or left side is placed against the IR.
Lateral radiographs are displayed on the illuminator as though the individual looking at the radiograph is in the position of the x-ray tube.
Oblique Projection - projection taken with the patient's body rotated
Oblique radiographs are displayed on the illuminator with the anatomy in the anatomic position.
Patient's left side is on your right, as though the patient were facing you.
When the radiologist (medical doctor who specializes in interpreting images) does not see the patient, he/she is dependent on the radiographer to take a detailed patient clinical history. This history, which is documented on the requisition, is read by the radiologist in conjunction with the viewing of the radiograph(s). An accurate clinical history aids the radiologist in making a correct diagnosis.
Common clinical history questions include:
What happened? Why are you having this examination?
- Do you have pain? Where? How long?
- Any previous fractures or surgeries to the area?
- What other symptoms are you experiencing?
Remember, it is crucial to ask a female of childbearing age what the first day of her last menstrual period was and if there is any chance of pregnancy.
The clinical history should be taken before proceeding with the radiographic procedure.
The radiographer is responsible for performing radiography of a given part using the department's set protocols (i.e. number and types of projections). Special/supplemental radiographs may be requested by the radiologist for further investigation.
Diagnosis and the Radiographer
Diagnosis is outside of the radiographer's scope of practice!
Diagnoses are made by radiologist.
An anxious patient should be told that he/she will be given a report of the findings by his/her referring physician, once the films have been interpreted by a radiologist.
Care of the Radiographic Examining Room
Should be clean/tidy
- Equipment (i.e. machinery, IRs, etc. ) used should be cleaned using a provided disinfectant after each patient examination.
- The radiographic room should be prepared before the patient enters.
Handle patients who are on isolation status appropriately (i.e. note when gloves, gowns, masks should be worn)
- Hand washing is the best means of preventing the spread of microorganisms
- Chapped/ dry hands should be treated
- Cuts on hands should be covered
- Remember after washing hands to turn off the faucet using paper toweling
- IRs should be protected if there is a chance they will come in contact with potentially infectious bodily fluids
- Infectious soiled linen should be properly bagged
Disinfectants and Antiseptics
Chemicals that kill pathogenic bacteria are termed germicides or disinfectants. (i.e. diluted bleach)
Chemical substances that inhibit the growth of pathogenic microorganisms are termed antiseptics.
Sterilization - the removal of all microorganisms requires the use of heat, specialized gases or potent
Centers for Disease Control and Prevention
The CDC has mandated that all blood and certain body fluids be treated as though they contain pathogenic microorganisms.
Appropriate personnel protective equipment must be used when any chance of contact exists.
Fluids that may contain pathogenic microorganisms:
- Blood containing fluids
- Amniotic fluid
- Pericardial fluid
- Pleural fluid
- Synovial fluid
- Cerebrospinal fluid
- Vaginal secretions
The beginning radiography student must be aware of the importance of preventing contamination in the operating room.
Appropriate attire must be worn
- Avoidance of radiographic equipment contaminating a sterile field
- IR placed in sterile covering before being used in the sterile field
Minor Surgical Procedures in the Radiology Department
Types: cystography - examination of the bladder requiring catheterization
intravenous urography - requires injection of contrast media
spinal punctures - performed during myelography procedures
angiography - requires use of needles, catheters placed into blood vessels
Above procedures require strict aseptic technique to be used.
- procedural protocols listed
- should be available to all department radiographers
Certain radiographic examinations require the patient's bowel to be clean of fecal matter.
Methods of bowel preparation: restricted diet (low residue diet), use of laxatives, use of enemas
Motion and Its Control
Motion, which is displayed on a radiograph as blurred anatomical structures, is undesirable.
Motion is classified as either involuntary or voluntary.
Involuntary motion cannot be consciously controlled by the patient.
Examples include: heart beat, chills, peristalsis (movement of the bowel), tremors, spasms, pain
Voluntary motion is under the control of the patient.
Examples include: breathing, unintended movement during the exposure
Motion is controlled by: providing patient comfort, using short radiographic exposure times, effective
communication, using immobilizing devices (i.e. tape, sponges, etc. )
A patient is more likely to follow instructions if he/she understands the reasoning behind the given instructions.
Instructions must be given in understandable/nontechnical terms.
Interpreters must be provided if there is confusion as to the given instructions.
Patient's Attire, Ornaments and Surgical Dressings
All radiopaque objects (objects which absorb radiation) must be removed from the area of interest. Included are: necklaces, belts, snaps, barrettes, hairpins, false teeth, buttons, thick elastic, earrings.
Examinations of the thorax, abdomen, spine and pelvis usually require that the patient be changed into a cotton hospital gown.
Surgical dressings/bandages must not be removed by the radiographer. The patient's nurse or physician may remove the bandaging for the radiograph. If bandages cannot be removed for the radiographic procedure, it must be documented on the patient's requisition.
Unintended optical densities on a radiograph are termed artifacts.
Handling of Patients
If patients are fearful of the examination, their fears should be alleviated.
If there will be discomfort involved, the patient should be told of this. He/she should also be told that all available steps will be taken to minimize his/her discomfort.
The radiographer should never rush a patient, especially a geriatric patient.
When manipulating the patient's body into position, it should be done gently but firmly.
Patients should be instructed to do as much of the moving as is possible.
Be aware that the patient may hold onto the sides of the table. This should be avoided because of the chance of his/her fingers being caught in the equipment.
Immobilization devices should be used when necessary, but not to the point of discomfort.
Explain to the patient that you will be palpating him/her to find landmarks which you will use in positioning.
Ill or Injured Patients
Great care must be exercised when dealing with trauma patients.
Review the six considerations p. 22
Most hospitals today have a specially equipped radiographic room adjoining the emergency department so that trauma patients do not have to be transported to the radiology department.
Identification of Radiographs
All radiographs must include the following:
- Patient's name or identification number
- Right or left marker
- Institution identification
Correct identification is paramount and should always be confirmed.
Some radiographs may require labeling with a cumulative time marker or identification of a special radiographic position.
Medicolegal requirements mandate that R or L lead markers are present on all radiographs.
1. The marker should never obscure anatomy.
2. The marker should never be placed over the patient's identification information.
3. The marker should always be placed on the edge of the collimation border.
4. The marker should always be placed outside of any lead shielding.
Image Receptor Placement
The anatomical part of interest should be centered to the middle of the film.
The IR is adjusted so that its long axis is parallel with the long axis of the part being examined.
Most institutions require both joints of a long bone to be included in a radiographic study.
IRs are placed as close to the anatomical part as is possible to avoid magnification.
In some instances, the same IR may be used for more than one exposure.
English-Metric Conversion and Film Sizes
With the exception of the United States, most countries now use the metric system for identifying film sizes.
Remember - 1" = 2.54 centimeters (cm)
8 x 10 inches
10 x 12 inches
7 x 17 inches = 18 x 43 cm
11 x 14 inches = 30 x 35 cm
14 x 17 inches = 35 x 43 cm
Direction of Central Ray
Generally the central ray is centered to the center of the IR.
The central ray is usually angled to remove or decrease superimposition of anatomical structures. It may also be used to decrease or increase the angulation of a given anatomical part.
Source to Image Receptor Distance (SID)
The distance from the anode inside of the tube to the IR.
Traditionally a 40" SID has been used. Many departments are now using 48".
72" are used for some exams including chest radiography.
As SID increases, magnification decreases.
Source to Skin Distance
The distance between the radiography tube and the patient's skin.
The current National Council on Radiation Protection (NCRP) states that the SSD shall not be less than 12" and should not be less than 15".
Collimation of the X-Ray Beam
Collimation = restriction of the radiation field
increase collimation - decrease dose and decrease scatter radiation
When practical, gonadal shielding should always be used to protect the patient.
Shielding should be used if the clinical objective of the examination is not compromised and if the patient has a reasonable reproductive potential.
Types of gonadal shielding: contact or shadow
CR uses standard radiographic equipment with specialized image receptors. The cassette is placed in a reader where it is taken and scanned with a laser. The final image appears on a computer screen.
Foundation Exposure Techniques and Charts
Exposure technique charts assist the radiographer in choosing the correct technical factors which should be used for a given radiographic exposure.
Sample items which appear on a technique chart:
- Automatic Exposure Control (AEC) information
Adaptation of Exposure Technique to Patient
Some conditions require the technique used to be increased or decreased.
Decreased Technical Factors: - old age
- degenerative arthritis
Increased Technical Factors: - pneumonia
- pleural effusion
- enlarged heart
Breathing instructions must be given to the patient and practiced before the exposure.
Inspiration = inhalation
Expiration = exhalation
The radiographer selects the correct technical factors documented on the technique chart and sets them up on the control panel before the exposure is made.
Repeat examinations may require an adjustment in the technical factor settings.
Remember as student radiographers, any radiograph that needs repeating must be repeated in the presence of a qualified radiographer.
Basic Radiation Protection and Radiobiology
1.Identify the sources of ionizing radiation.
2.Describe the units used to measure radiation exposure.
5.List the permissible limits of exposure for occupational and nonoccupational workers.
6.Explain the reason for the varying sensitivity of body cells to ionizing radiation.
•Loss of electrons results in ionization of atoms.
•Two sources of ionizing radiation - natural and man-made
–Roentgen (Coulombs per Kilogram)
•Measures exposure in air and is not used to express absorbed dose to individuals
•Expressed as rad
•Accounts for different types of radiation and their biologic effects
•Measures the activity of a radioactive material (radionuclide)
Protecting the Patient
•Cardinal Rules of Protection
•These doses are far greater than those received by the occupational worker or patient.
Critical-Thinking and Problem-Solving Strategies
Taxonomy of Learning
Critical thinking skills require learning in all three of the domains.
•Critical thinking requires more than just the simple recollection of knowledge and facts.
•Learning activities may consist of problem solving, role playing, lab simulations, case studies, situational judgment questions on exams, and so on.
•Critical thinking will require you to thoroughly understand your ethical responsibilities.
•A complete understanding of the principles of this profession is essential.
1.Identify the problem.
2.Analyze the problem objectively.
Radiographic and Fluoroscopic Equipment
X-Ray Machine Design Functions
•Controls the size and shape of the x-ray field directed toward the patient
•Projects a high-intensity light field on the patient, which represents the area of the x-ray field exposure
Digital radiography (DR) systems have replaced the cassette tray and moving grid with a stationary grid and no tray
A proper balance between photographic and geometric qualities is required for optimum image quality.
Calculated by simple multiplication of milliamperage (mA) and exposure time (S)
400 × 0.040 = 16 mAs
200 × 0.080 = 16 mAs
•Controls x-ray beam penetration
I1/I2 = D22/D12
Distance and mAs:
mAs1/mAs2 = D12/D22
Half Value Layer:
Computed Radiography and Exposure:
Direct Detector Technology:
Indirect Detector Technology:
Digital Radiography Key Features:
Brightness of image is not the same as radiographic density and not related to exposure
Focal Spot Size:
Maslow's Hierarchy of Needs
•People strive from a basic level of physiologic needs toward a level of self-actualization.
May be necessary to verbally explain examination prep directions or information on consent forms.
Common Patient Types
Mobile and Surgical Patient Communication
Age as a Comminication Factor
Five Stages of the Grieving Process
Patient History Process
Elements of Clinical History
- Define the terms associated with body mechanics.
- Describe the cause, signs, symptoms, and treatment of orthostatic hypotension.
- Describe the basic principles of proper lifting and transfer techniques.
- Explain four types of wheelchair-to-bed transfers.
- Explain a standard cart transfer procedure.
- Identify five standard patient positions.
The purpose of a patient transfer is to safely move a patient from one place to another.
Safety involves both the patient and the people doing the transfer.
The application of proper lifting and transfer techniques increases job safety.
Radiologic imaging professionals who use proper transfer techniques can reduce their injuries and minimize low back pain.
- Fundamental to good patient handling techniques are the concepts of the base of support, center of gravity, and mobility and stability muscles.
- The base of support is the foundation on which a body rests.
- Base of support is the area between the feet, including the plantar surface area, in a standing position.
- A wider stance improves your base of support.
- Standing with both feet flat on the floor improves the base of support.
- Standing with feet apart to increase the base of support improves stability.
- Standing on “tiptoes” decreases surface in contact with the floor and narrows the base of support.
Center of Gravity:
- A hypothetical area of the body where the mass of the body is concentrated; gravity works from this area
- Typically at level of second sacral segment
- Holding heavy objects close to your center of gravity permits easier and safer transfer
- Stability can be achieved when a body’s center of gravity is over its base of support
Good Body Mechanics:
- Use good posture.
- Always keep your body’s line of balance close to your center of gravity (below waistline).
- Hold object close to body.
- Bend your knees.
- Don’t twist your trunk.
- Push rather than pull.
- Extremity muscles are classified as mobility muscles.
- Muscles of the torso are stability muscles.
- For effective patient transfers and handling, technologists should use mobility muscles for lifting and stability postural muscles for support.
Transfer Techniques Mean Teamwork
- Someone needs to take charge of the transfer
- Reviews procedures with team members
- Calls the play
- Establishes timing of play
- Synchronizes play events
- Lifting should be done by bending and straightening the knees.
- The back should be kept straight or in a position of slightly increased lumbar lordosis.
- Allow ample time, and handle patients gently.
- Always inform the patient of what you are going to do and how you intend to proceed.
- When performing a transfer, let patients do as much of the work as possible.
- Before executing the transfer, check the patient’s chart and verify whether he or she has a restricted weight-bearing status.
- Patients with cognitive impairments, such as dementia, may overestimate their transfer abilities and require assistance.
- Execute the transfer slowly enough for the patient to feel secure.
- The patient’s center of gravity should be held close to the transferer’s center of gravity.
- Taking a transfer belt is a good practice when planning to perform transfers.
- Avoid loose clothing on the patient.
- Let patients perform as much of the transfer as they can.
- When lifting patients, keep the back stationary and let the legs do all of the lifting.
- Twisting should be avoided.
- After the patient is standing, help him or her to pivot around to a bed or x-ray table and to sit down.
- A sudden drop in blood pressure caused by a change in a patient’s body position
- More pronounced in patients who have been bedridden for extended periods
- Symptoms of orthostatic hypotension include dizziness, fainting, blurred vision, and slurred speech
- To minimize the severity of orthostatic hypotension, have the patient stand slowly
- Encourage the patient to talk during the transfer by asking simple questions
- Do not send a symptomatic patient away and risk having the patient faint on the way to his or her room
Skin Damage From Transfers:
- Can occur in as little as 1 to 2 hours
- May occur going from one surface type to a different surface type
- Caused by several mechanical factors
- Determine patient’s strong and weak sides
- Always position the patient so that he or she transfers toward the strong side
- Lock wheelchair locks and move footrests out of the way
- Used for patients who have the ability to transfer from a wheelchair to a table on their own
- Provide movement instructions to the patient continually during transfer
Hydraulic Lift Techniques:
- Used for heavy patients
- Familiarize yourself thoroughly with lift operations before using this type of lift
- Patients need to be seated on a lift sling before using this type of lift
- Sending a patient back to the ward to return sitting on a sling is better than risking injury to the patient, the transfer, or both by attempting transfer without using a sling
- Communication is critical to lift success
- Make sure cart wheels are locked and immovable.
- Allow patient to assist with move based on the patient’s ability and condition.
- Cart transfers usually require three people.
- Use transfer aids.
For the actual lateral transfer, both transfer surfaces must be side to side, as close as possible, and at the same height.
Patient Positioning Considerations:
- Talk with the patient and explain what you are going to do.
- Let the patient assist as much as possible.
- Check with patient before any move is attempted.
- Provide positioning sponges to help the patient maintain correct positioning.
- Work as a transfer team!
- Communication with patient and team members is critical to safe and efficient transfers.
- Work as a transfer team with a clear leader during the transfer.
- Let the patient assist with transfers if possible.
- Use a broad base of support, and maintain your center of gravity over base during lift.
- Use transfer and positioning aids when possible.
Final Examination Review
- Hospital Boards employ either a president or CEO to interact with the medical staff.
- Hospital's mission statement - its guiding force which outlines its existence.
- to turn the latent image into the manifest image, processing must occur
- radiopaque - material is not easily penetrated by x-rays
- radiolucent - material is easily penetrated by x-rays (little absorption)
- PBL - positive beam limitation - automatic collimation
- manifest image - visible image
- latent image - invisible image
- density - overall blackness of the image
- contrast - diffences in radiographic densities on an image
- central ray - theoretical center of the beam
- attenuation - absorption of the radiographic beam
- radiographer controls: kVp, mA, distances, time, focal spot size
- distortion - misrepresentation of the true size and/or shape of the radiographed object
- increase mAs, increase density
- increase kVp - increase density, decrease contrast
- to double density/exposure to the film: double the mAs or increase the kVp by 15%
- be familiar with solving problems using the inverse square law
- lead is used for shielding purposes
- aluminum is used for filtering purposes
- light localizing variable aperature collimators, cones, cylinders and aperature diaphragms are all used to restrict the beam
- increase the screen speed - less radiation is needed to produce a given density
- main controlling factor of density = mAs
- main controlling factor of contrast = kVp
- high kVp = increase scatter reaching the film = long scale contrast (more grays) = low contrast
- low kVp - short scale contrast - image is more black/white
- increase SID - decrease magnification
- decrease SID - increase magnification
- increase OID - increase magnification
- decrease OID - decrease magnification
- anode - positive diode
- cathode - negative diode
- buckys contain a grid to absorb scatter radiation before it interacts with the IR
- x-ray tubes produce x-rays and heat
- diagnostic x-ray tubes produce x-rays in the range of 30 - 150 kVp
- moving tube at right angles across the table = transverse
- moving the tube lengthwise to the radiographer's right or left = longitudinal movement
- moving the tube towards the ceiling or down towards the floor = vertical movement
- pivoting the tube at its point of attachment to its support = tube angulation
- fluoroscopy provides dynamic (moving) radiographic images
- when using a bucky, the tube must be in detent
- collimators control the size and shape of the x-ray field
- to produce x-rays in a tube you must have a vacuum, a source of electrons (mA -filament), acceleration of the electrons (kVp), sudden stopping or slowing down of the electrons (anode)
- be prepared calculate mAs values (remember ms must be changed to seconds by dividing the ms by 1000)
- rad - radiation absorbed dose - Gray
- rem - dose equivalence - Sievert
- Roentgen - measures ionizations in air - C/Kg
- Curie - measures radioactivity - Becquerel
- photoelectric - interaction of x-rays and matter - inner shell interaction - true absorption
- Compton - interaction of x-rays and matter - outer shell interaction - scatter
- Bremsstrahlung - x-ray production - incoming (incident) electron slows down - lost kinetic energy in the form of an x-ray photon
- Characteristic - x-ray production - incoming (incident) electron dislodges inner shell electron of tungsten and creates a characteristic cascade
- sperm and egg = germ cells
- all other cells of body = somatic cells
- direct hit theory = involves x-ray interaction with DNA
- indirect theory = involves x-ray interaction with water
- prodromal stage - symptoms = nausea, vomiting and diarrhea
- syndromes: bone marrow syndrome (200 - 1000 rads), GI syndrome (1000 - 5000/10,000 rads), CNS syndrome (greater than 10,000 rads)
- cardinal principles of radiation protection = time, distance, shielding
- declared pregnant student - voluntarily declares pregnancy
- Geiger Muller counters - measures radiation in a given area (field)
- JRC-ERT - provides guidance to radiography programs
- JRC-ERT - provides the Standards of Accreditation for radiography programs
- competency based curriculum = didactic instruction, laboratory instruction, clinical education
- ARRT reports scores for those taking the Registry Exam as scaled scores, which take into account the difficulty of given questions
- students must earn a scaled score of 75 on the Registry Examination to pass and become an R.T. (R)
- ASRT - professional organization for radiographers
- on passing a clinical competency, the student may perform radiography under indirect supervision
- repeat images must be taken in the presence of a qualified radiographer
- students are supervised by: staff radiographers, CI, CC, program director, didactic instructors, radiologists
- x-rays discovered by Wilhelm Conrad Roentgen on November 8, 1895 at the University of Wurzburg while using a Crooke's tube
- mammographers specialize in radiography of the breast
- elements of critical thinking = analysis, synthesis, evaluation, critique
- umbra = area of image sharpness
- penumbra = area of image unsharpness
- Diversity - addresses the entirety of the ways individuals are different, yet similar
- Racism - belief that one race or culture is superior to another
- objective data is perceptible to the senses
- when taking a patient's history - open ended questions should be used