RADS.100 - Fundamentals of Radiography

Course Description

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

•Medical radiation sciences uses energy to create images of the human body.

•Various energy forms may be used depending on the application.

•Some energies create ionizations in human tissue.

Energy Forms for Imaging:

•Medical radiation sciences uses energy to create images of the human body.

•Various energy forms may be used depending on the application.

•Some energies create ionizations in human tissue.

Electromagnetic Energy Plays a Very Important Role in Radiologic Sciences.

• Radiography uses electromagnetic energy in the form of x-rays to create medical images.

Medical Sonography:

•Uses high-frequency sound energy to create medical images

•Does not create ionizations

•Has wide variety of medical applications

MRI:

•Uses the energy of high-strength magnetic fields and radio waves to create images of the human body

•Creates no ionizations

CT Scanning:

•Uses x-ray energy and sophisticated software to create images of the human body

Nuclear Medicine:

•Uses the energy of the atom to create medical images

•Energy form is gamma radiation

•Uses radioactive isotopes to create gamma radiation

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

Radiation Therapy:

•Uses very–high-energy ionizing radiation to treat malignant tumors (cancer)

•Radiation therapists work with other team members to improve the quality of life of cancer patients

History of Radiology:

•Discovered by Wilhelm C. Röngten

•November 8, 1995

•Received Nobel Prize in Physics in 1901

•First known x-ray image is of wife’s hand

Radiologic Sciences as a Career

•Offers a wide variety of career paths

•Often begins with a general radiography background

•Specialty areas require additional education and certification

•Career opportunities are nearly limitless and demand initiative and a desire for professional success

Career Opportunities:

•Radiography

•CT Scanning

•Medical Sonography

•Radiation Therapy

•MRI Scanning

•Mammography

•DEXA Scanning

•Radiologist Assistant

•Nuclear Medicine

•Cardiovascular Interventional Technology

•PACS Administrator

•Radiology Administration

•Education

•Research

•Commercial Firms

–Sales

–Applications

–Service

Radiology:

•Can be referred to by a number of different names

–Radiology

–X-ray

–Medical imaging

–Diagnostic services

–Imaging services

–Imaging

•Predominantly a diagnostic service that focuses on imaging of patients to diagnosis their medical condition

Health Care Team:

–Physicians - M.D. and D.O.

–Nurses

–Allied health – i.e. radiographers, therapists

–Supporting members

•Nonclinical

•Most health careers are referred to as allied health

•Hospitals are communities within communities

Conclusion:

•X-rays were discovered by W.C. Röngten in 1895.

•Medical imaging consists of many diagnostic areas involving energy, and particularly, radiant energy.

•Radiologic sciences professionals perform as essential members of a healthcare team.

•Career opportunities are nearly limitless and demand initiative and a desire for professional success.

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

3. Nondiscrimination

4. Utilization of Learned Knowledge

5. Responsibility

6. Communication

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

Four Types

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

Radiograph

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

is undesirable

7. Recognition of shape distortion - misrepresentation of the size or shape of the anatomical

structure

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.

1. mAs

2. kilovoltage (kVp)

3. distance

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

illuminator)

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

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

ceiling.

- 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.

Clinical History

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.

Initial Examination

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.

Standard Precautions

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.

(i.e. alcohol)

Sterilization - the removal of all microorganisms requires the use of heat, specialized gases or potent

chemicals.

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
Blood containing fluids
Amniotic fluid
Pericardial fluid
Pleural fluid
Synovial fluid
Cerebrospinal fluid
Semen
Vaginal secretions

Operating Room

The beginning radiography student must be aware of the importance of preventing contamination in the operating room.

Appropriate attire must be worn

- scrubs

- caps

- masks

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.

Procedure Book

- procedural protocols listed

- should be available to all department radiographers

Bowel Preparation

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. )

Patient Instructions

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:

Date
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.

Anatomic Markers

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)

Film sizes:

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

Gonadal Shielding

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

Computed Radiography

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:

- projection

- kilovoltage

- mAs

- SID

- 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

- pneumothorax

- emphysema

- emaciation

- degenerative arthritis

- atrophy

Increased Technical Factors: - pneumonia

- pleural effusion

- hydrocephalus

- enlarged heart

- edema

- ascites

- obesity

Preexposure Factors

Breathing instructions must be given to the patient and practiced before the exposure.

Inspiration = inhalation

Expiration = exhalation

Technical Factors

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

Objectives

1.Identify the sources of ionizing radiation.

2.Describe the units used to measure radiation exposure.

3.Describe the nature of ionizing radiation.

4.Explain the ways in which ionizing radiation interacts with matter.

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.

7.Describe the ways in which the entire body responds to varying amounts of radiation.

8.Discuss the various methods used to protect the patient from excessive radiation.

9.Discuss the various methods used to protect an occupational worker from excessive radiation.

10.Describe several devices used to detect and measure exposure to ionizing radiation.

•Radiation has sufficient energy to cause the ejection of electrons from atoms.

•Loss of electrons results in ionization of atoms.

•Ionization can have biologic effects.

•Risks of ionization must weigh less than the benefit of the x-ray diagnostic study.

•Two sources of ionizing radiation - natural and man-made

•Human-made radiation occurs from several sources

•Medical and dental x-ray examinations make up the largest portion of human-made radiation exposure

Photoelectric

•Occurs within the diagnostic x-ray energy range

•Incoming x-ray photon is completely absorbed by collision with inner-shell electron

•Electron (photoelectron) leaves atom, creating an ion pair

•Free electron eventually unites with other matter

•Secondary radiations created as a result of electron cascade from outer shells to inner shells

Compton

•Occurs within the diagnostic ranges of x-ray energies

•Incoming photon collides with outer-shell electron, creating a free Compton electron (recoil) and an ion pair

•Incoming photon loses some of its energy through collision, scatters off in a random direction (scatter angle), and undergoes other interactions until its energy is gone

Pair Production

•Requires very high energy photons

•Incoming photon must have at least 1.02 MeV of energy

•Interacts with nuclear force field around nucleus and disappears

•Two particles reappear, each with equal energy (0.51 mEv)

•The positron collides with a free electron and creates an annihilation reaction

•Annihilation reaction creates two photons at opposites angle to each other

Photodisintegration

•Requires photon energies that are extremely high

•Incoming photon interacts with nucleus of atom, creating nuclear instability

•Nuclear fragment is given off as nucleus seeks stability

•Common interaction in the nuclear industry

•The SI units (Système International d’Unités, or International System of Units) were officially adopted in 1985.

–Roentgen (Coulombs per Kilogram)

–Radiation Absorbed Dose (Gray)

–Radiation Equivalent Man (Sievert)

–Curie (Becquerel)

Roentgen

•Measures exposure in air and is not used to express absorbed dose to individuals

•A measure of ionization in air as a result of exposure to x-rays or gamma rays

RAD

•Expressed as rad

•Measures the amount of energy absorbed in any medium, defined as 100 ergs of energy absorbed in 1 g of absorbing material

REM

•Accounts for different types of radiation and their biologic effects

•Expressed as the product of the absorbed dose in rad and a radiation quality factor

rem = rad × QF QF for x-rays = 1 QF for alpha particles = 20

CURIE

•Measures the activity of a radioactive material (radionuclide)

•Used in nuclear medicine and radiation therapy

•The curie (Ci) is the unit of activity equal to 3.7 × 1010 disintegrations per second (dps)

•SI unit of activity is the becquerel (Bq)

–defined as one disintegration per second (1 dps)

–1 Ci = 3.7 × 1010 Bq

•Standards are regulated by the FDA and its Center for Devices and Radiological Health (CDRH).

•Effective dose limit recommendations have been set to minimize the biologic risk to exposed persons.

• An individual’s dose should be kept as low as reasonably achievable (ALARA).

•The annual whole-body effective dose limit for the occupational worker is 50 mSv (5 rem).

•Physicians use a “risk vs. benefit “ rationale when ordering ionizing radiation studies.

•Benefits of exam must outweigh the potential risks from radiation exposure.

•Doses should be kept as low as possible, and no dose is considered totally permissible.

Radiobiology

•Cells have two major parts - nucleus and cytoplasm

•Genetic material of cell contained in nucleus

•80% of cell content is water

•Two classes of human cells - somatic (all cells of the body other than germ cells), germ (sperm/egg)

•Cells have different degrees of radiosensitivity

•Cellular radiosensitivity is principally a result of the rate and duration of cellular mitosis (increased mitosis = increased radiosensitivity)

•Fortunately, most cells can recover from radiation damage

Protecting the Patient

•Cardinal Rules of Protection

–Time

–Distance

–Shielding

•X-ray beam restriction

•Image receptor speed

•Filtration

•Optimum exposure technique selection

Radiation Syndromes

•These doses are far greater than those received by the occupational worker or patient.

1.Bone Marrow Syndrome

2.Gastrointestinal Syndrome

3.Central Nervous Syndrome

Radiation Monitoring

•Any occupational worker who is regularly exposed to ionizing radiation must be monitored to determine estimated exposure

•Any worker who is likely to receive more than one tenth of the recommended dose-equivalent limit should be monitored

•Known as personnel monitoring dosimeters ( i.e. film badges, OSL, TLD, etc.)

•Monitors measure the quantity of radiation received based on conditions in which the radiographer was placed

•Exposure data are collected for a specified period of time

•Worn at the collar level

•Worn outside of lead apron

•Device should face forward

•Pregnant radiographers may have a second device worn at waist level and under the lead apron

Conclusion

•X-radiation has the potential to create ionizations in human tissue.

•Ionizations can be harmful and cause cell disturbances and genetic alterations.

•Effects may be early or late and are dose dependent.

•Use the Cardinal Rules of Protection.

•Radiographers have a professional responsibility to consistently practice ALARA.

Critical-Thinking and Problem-Solving Strategies

Taxonomy of Learning

Critical thinking skills require learning in all three of the domains.

•Cognitive Domain

•Affective Domain

•Psychomotor Domain

•Critical thinking involves sound professional judgment applied with high ethical standards and integrity.

•The nature of medical imaging inherently requires critical-thinking skills.

•Critical-thinking skills are a trait that employers expect in competent radiologic science professionals.

•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 skills are taught at higher levels of learning that require skills in the analysis, application, and evaluation of content.

Problem-Solving and
Critical-Thinking Steps

1.Identify and clarify the problem.

2.Perform an objective analysis of the problem.

3.Develop realistic solutions to the problem.

4.Consider all viable solutions to the problem.

5.Select the best solution to the problem, and implement it.

•Critical-thinking skills are taught in a variety of learning settings.

•Critical thinking also involves your values and attitudes toward various situations encountered in medical imaging.

•Critical thinking will require you to thoroughly understand your ethical responsibilities.

•Every patient experience is unique and requires adaptive measures in a wide variety of settings.

•A complete understanding of the principles of this profession is essential.

Case Studies

1.Identify the problem.

2.Analyze the problem objectively.

3.Develop viable solutions.

4.Select the best solution, and implement it.

•Critical-thinking skills are vital in the radiologic sciences.

•Learning occurs at three levels or domains and deals with general knowledge, attitudes and values, and psychomotor skills.

•Critical analysis is a four-step process.

•Good critical-thinking and problem-solving skills are the mark of a professional imaging technologist.

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Radiographic and Fluoroscopic Equipment

Diagnostic Yield

•The amount of clinically useful information on a diagnostic image

•Different medical imaging modalities provide different types of information

–Sonography

–CT scanning

–MRI scanning

•Each modality has its own considerations for ordering the procedure.

•Physicians expect a certain amount of diagnostic yield when exams are ordered.

•Diagnostic yield of information must outweigh the input factors of the procedure.

•Competent imaging professionals will strive to maximize diagnostic yield using a minimum of input factors.

Diagnostic Efficacy

•The accuracy of diagnostic information on a medical image is its diagnostic efficacy.

•Any extraneous information on an image that does not reflect the patient’s true medical condition detracts from diagnostic efficacy.

•Diagnostic efficacy and diagnostic yield must be optimized as the standard of care.

X-Ray Machine Design Functions

X-ray tube and x-ray tube support

•Collimator assembly

•X-ray table

•X-ray generator and control

•Upright image receptor

•X-ray tube is inside of the tube housing

•Made of Pyrex glass

•Produces x-radiation when high energy electricity is passed through

•X-radiation exits the x-ray tube though a window in the housing and is directed toward a patient

Collimator Assemby

•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

•May be manual or automatic (PBL)

Radiographic Table

•May be fixed height or variable height

•Typically has a four-way “floating” tabletop

•Some table designs permit a variable-speed, tilting capability

•Tabletop is highly radiolucent

Tilting Radiographic Table

•These designs will tilt the table from horizontal position to vertical upright position to Trendelenburg

•Most tables have four-way tabletop travel

•Often referred to based on Trendelenburg tilt angle

•These tables do not have variable height capabilities

Digital radiography (DR) systems have replaced the cassette tray and moving grid with a stationary grid and no tray

Generator Console

•Control console is the interface between the radiographer and the sophisticated electronics of the x-ray machine

•Console features

•Most are microprocessor- controlled and use a simple computer interface

Exposure Technique

•Consists of three (3) key factors - kVp, mA and time

•Automatic exposure control (AEC) may be optional

•Focal spot size selection

•Generator consoles permit selection of kVp, mA, exposure time (S), and mAs

•May be operated in the mAs mode or timer mode

•Newer systems feature APR

•Technique selection is critical to good radiography

X-Ray Tube Supports

•Two basic designs - Floor Mounted and Ceiling Suspended

•Facilitate easy and efficient positioning of the x-ray tube assembly around the patient in any orientation

•Capable of various motions depending on need

•Ergonomically friendly

•Esthetically pleasing and not intimidating to patients

User Friendly OTC

•Newer overhead tubecrane designs permit selection of exposure factors at the tubehead control, with a flat panel screen.

•Digital radiography systems may display the image from the last exposure for review.

•Exposure still requires the operator to be behind the control booth.

Image Receptor Technology

•Receives remnant radiation from patient and captures the x-ray energy for processing

•Classified as cassette-based and cassetteless

•Historically, receptor was intensifying screens and polyester film

•Newer systems replacing the film-screen–based technology with digital technology displayed on a video monitor

Image Receptors

•Cassette-based systems

–Film-screen

–Computed radiography (CR)

•Digital radiography (DR) systems

•Referred to as flat panel technology

–DR systems use thin-film transistors (TFTs)

–Indirect digital detector technology

–Direct digital technology

Photostimulable Phosphor Technology

•Also known as storage-phosphor technology

•Commonly referenced as computed radiography (CR)

•Uses reusable imaging plates coated with a barium fluorohalide crystal

•Creates electron traps in the phosphor

•Depth of electron trap atomically is directly related to the x-ray energy that created the trap

•Cassettes with imaging plates (IPs) come in three sizes

PSP Technology

•Light emitted from electron traps is captured by a light “waveguide” assembly and converted to an electrical signal.

•Electric signal is an analog signal.

•Analog signal is converted to a digital signal by an A/D convertor.

•Digital signal is analyzed by software to create a finished image.

•CR plate that has been scanned by laser beam is exposed to intense white light.

•Clean plate is reinserted into cassette for reuse and ejected from reader.

CR imaging plates (IPs) can be used for thousands of exposures per plate

•CR plates are extra sensitive to low-energy radiation after they have been exposed.

•Electron traps can “dissolve” with lengthy delays in processing in reader.

•There is a resolution difference among cassette sizes.

DR Technology

•Replacing cassette-based systems

•Improved spatial resolution

•More dose efficient

•Detectors are very expensive and must be treated with care

•Radiographic grids very important

•DR opening new imaging technologies

Fluoroscopy

•Provides live, real-time images of patients using x-rays

•Standard of care for studying patient physiology and dynamics using x-radiation

•Requires special equipment designs that feature an x-ray tube with attached image receptor in an orthogonal relationship

•Used for a wide array of diagnostic procedures

Radiographic/Fluoroscopic System (RF System)

•Capable of static radiographic imaging (spot films) as well as live imaging (fluoroscopy)

•Capable of vertical tilting

•Spot film device with image intensifier is at right angle to x-ray tube during fluoroscopy

•Table-side controls of tabletop motions

•Image receptor is typically an image intensifier tube

•Considered the primary barrier

•Lead curtain drape on front of spot device to lower exposure of operators

Interventional C-Arm Fluoroscopy System

•Used for interventional procedures

•Features a C-arm design with x-ray tube and image receptor

•Newer systems use a flat panel DR detector

Mobile X-Ray Imaging

•Mobile radiographic units used extensively in hospital in many settings

•Travel movement is motorized

•X-ray capabilities similar to those of a fixed radiographic unit

•Designs are compact and user-friendly

•Limited power for x-ray studies

•Motorized motion

•High-frequency output

•Exposure switch on a coiled cord to maximize distance from patient during exposure

•Need to be plugged into wall outlet for charging when not in use

•Newer systems use a portable DR detector to replace cassette

Mobile Fluoroscopy

•Used in surgery and interventional exams

•Uses a C-arm design

•Image receptor is at a fixed SID and centered to x-ray tube

•Receptors vary from 6- to 12-inch input diameter

•Limited power

•Video monitors and computer for digital enhancement of images included in a monitor cart

•The highest diagnostic yield and efficacy of images are a constant goal.

•Radiographic equipment has various designs but many common features.

•Receptor technology will continue to evolve into digital world.

•Equipment design will incorporate digital detectors and user-friendliness.

•The basic principles of x-ray production and image quality remain the same, even in the digital world.

RADIOGRAPHIC IMAGING

Objectives:

1.Discuss primary, scatter, and remnant radiation.

2.Describe the fundamentals of image production.

3.Describe the three major categories of image receptor systems used today in radiography.

4.Compare and contrast the latent image formation process for film-screen radiography, photostimulable phosphor systems, and indirect and direct capture digital radiography.

5.Discuss image quality in terms of image receptor exposure and density, contrast, recorded detail, and distortion.

6.Describe fluoroscopic imaging.

•X-rays were discovered in 1895.

•X-ray beam energy is produced using high-voltage electricity.

•X-rays pass through matter and strike an image receptor.

•Image receptor converts the energy of x-rays into an image.

Classes of Diagnostic Imaging Devices:

1.Film-screen radiography

2.Fluoroscopic imaging

3.Digital or computerized imaging

X-Ray Production Requirements:

1.X-ray tube with a vacuum inside

2.Source of electrons

3.Method to accelerate electrons to great speed

4.Method to stop electrons

Classes of Radiation:

•Primary radiation

•Scatter radiation

•Absorbed radiation

•Remnant radiation

Attenuation of Radiation:

•Attenuation is the loss of radiation energy as a result of passing through an absorbing material, such as the human body.

•The degree of attenuation can be high or low.

•High attenuation occurs in radiopaque matter.

•Low attenuation occurs in radiolucent matter.

Imaging Chain:

•Primary radiation from the x-ray tube travels through matter, and its energy is finally detected by an image receptor.

•Remnant radiation creates chemical changes within the receptor that are invisible.

•The latent image must be processed to convert it to a visible image (radiograph).

Film Screen Radiography:

•Uses x-rays to create a permanent image on a piece of polyester film

•Consists of x-rays directed at a radiographic cassette with an intensifying screen

•Intensifying screens convert the x-ray energy to light, and light energy creates chemical changes in film

•Exposed x-ray film is chemically processed in a wet chemistry automatic processor

•Processing converts latent image into a manifest image (radiograph)

•Radiograph is analyzed for quality and submitted to radiologist for interpretation

•Rapidly being replaced by digital technologies

Technical Exposure Factors:

•Milliamperage (mA) and Time (seconds)

•Kilovoltage Peak (kVp)

•Source-to-Image Distance (SID)

A proper balance between photographic and geometric qualities is required for optimum image quality.

Image Density:

•The overall darkness or blackness of an image

•Directly related to x-ray exposure hitting the receptor

•Primarily affected by milliamperage, exposure time, source-to-image distance (SID)

mAs is a primary factor of density:

•mAs represents the quantity of x-ray production

•Direct relationship

Calculated by simple multiplication of milliamperage (mA) and exposure time (S)

400 × 0.040 = 16 mAs

200 × 0.080 = 16 mAs

•Regardless of the mA and time combinations, the same mAs value will yield the same exposure (mAs reciprocity law).

Kilovoltage Peak:

•Controls x-ray beam penetration

•Direct relationship

•X-ray beam is polyenergetic or heterogeneous

•15% Rule - to maintain density, increase the kVp 15% and decrease mAs by 1/2

Distance:

•Displayed as Source-to-Image Distance (SID)

•X-ray production is similar to a point light source

•Behaves according to the laws of light and intensity as a function of distance

•Inverse Square Law

I1/I2 = D22/D12

Distance and mAs:

mAs1/mAs2 = D12/D22

Beam Modification:

•The x-ray beam can be modified before and after it enters the patient.

•Beam alterations can improve image quality and reduce dose.

•Primary beam modification is of two types.

•Modification of remnant radiation is a scatter control process.

Scatter Control:

•Interaction of x-rays with any matter produces scatter radiation

•Scatter radiation provides little diagnostic information to image

•Detracts from image quality with the creation of fog

•Common methods of scatter control

Grids:

•Used to reduce the amount of scatter radiation reaching the image receptor

•Intercept a portion of the remnant radiation

•Improve image quality

•Grids described according to grid ratio and frequency

•Necessitates an increase in exposure to compensate for grid

Half Value Layer:

•The amount of absorbing material that will reduce the intensity of the x-ray beam to ½ its original value

•Used as a way to express x-ray beam quality

Image Receptor:

•Image receptors detect the remnant radiation from the patient and convert it into chemical or electrical changes that make up the latent image

•Three (3) types of image receptors

Film-Screen Receptors:

•Radiographic film has been the primary recording medium for several decades.

•It uses special film that is sensitive to light energy from an intensifying screen.

•Light from the screen causes chemical changes in the film and creates the invisible latent image.

•Film with the latent image is processed through various chemicals to yield the manifest image.

•Film is between two intensifying screens in a light-tight cassette.

•Cassette with film and screen is exposed to remnant radiation.

•Film is removed from cassette in a darkroom environment and placed in an automatic film processor.

•Intensifying screens allow for lower x-ray dosages to patients.

Digital Receptor Systems:

•Photostimulable Storage Phosphor (PSP) Technology

•Also known as Computed Radiography (CR)

•CR is a storage phosphor technology

•Uses a cassette with imaging plate (IP)

•Exposed IP in cassette is placed in a reader for electronic processing of the latent image into a manifest image displayed on a monitor

•Eliminates the need for an x-ray film darkroom

•Ultimately creates a digital image through computer software

Computed Radiography and Exposure:

•Exposure to plate is stored in barium fluorohalide crystals that create electron “traps”

•Requires the optimum combination of mAs, kVp, and SID for optimum image quality

CR Reader:

•Cassette with IP placed in CR Reader

•Reader scans the IP with energy and recovers the energy from the electron traps

•This energy is converted into manifest image

Digital Cassetteless Systems:

•Two methods of digital image capture

•Image resolution is determined by the pixel size of each data element

•Images consist of pixel elements in a rectangular array

•Both methods use thin-film transistor (TFT) technology

Exposure Considerations with DR Receptors:

•Several key factors that must be considered when evaluating proper image receptor (IR) exposure

•Digital detectors possess greater exposure latitude than conventional film-screen systems

•DR systems can be operated at varying system sensitivities, known as system speed

Exposure Index:

•A numeric representation of total x-ray exposure to the receptor

•EI is not an indicator of the patient’s absorbed dose

•EI values can vary greatly among manufacturers

•Professional technologists will thoroughly understand the significance of the EI value and use it wisely

Automatic Rescaling:

•Computer software that optimizes image quality by varying the brightness and contrast of the image based on the exposure to the receptor

•Too little exposure results in noisy or grainy images

•Too much exposure technique can reduce image contrast

•Automatic rescaling is no excuse for exposure technique selection inaccuracies

Image Display Parameters:

•Digitally created images are viewed on television computer monitors.

•Images can be adjusted in terms of brightness and contrast.

•Window level (WL) controls image brightness.

•Window width (WW) controls contrast.

Direct Detector Technology:

•Uses amorphous selenium as the active detector material

•Uses TFT to capture electrons from x-ray interactions

•TFT collects and amplifies the electron signal

•Electron signals are converted to computer data and displayed as an image

Indirect Detector Technology:

•Uses a scintillator material bonded to amorphous silicon

•Scintillator receives the x-ray energy and converts it to light energy.

•Light energy is captured by amorphous silicon and converted to electrons

•Electrons are collected by TFT and sent to computer

Digital Radiography Key Features:

•Uses no cassettes

•Image display is in seconds

•Detectors can be direct or indirect

•Both types use thin-film transistors

•Indirect detector uses cesium iodide as a scintillator with amorphous silicon

Brightness of image is not the same as radiographic density and not related to exposure

Geometric Qualities:

•Contribute to image quality by affecting image resolution, size, and shape

•Also known as recorded detail, definition, sharpness of detail, and definition

•Complemented by visibility of detail, which is a photographic property

Factors Affecting Recorded Detail:

•Motion

•Object unsharpness

•Focal spot size

•SID

•Object-to-image distance (OID)

•Material unsharpness

•Distortion

•Motion distortion is the most common cause of image unsharpness

•Caused by voluntary and involuntary patient motion

Object Unsharpness:

•Loss in resolution caused by the inherent shape of the patient’s anatomic structures relative to the divergence of the x-ray beam

•Lessened by optimum use of focal spot size, OID, SID

Material Unsharpness:

•Loss in resolution caused by the inherent characteristics of the image receptor material

•Screen-film unsharpness is a result of the size of the silver grains in the film emulsion and the size of the screen phosphor

•Digital detector unsharpness is caused by the pixel element size of the detector technology

Focal Spot Size:

•Loss in resolution caused by dimensional shape of the actual target area on the anode surface

•Reduced by using the smallest dimension possible based on x-ray tube manufacturer’s specifications

SID:

•Distance between x-ray tube target and image receptor

OID:

•Distance between patient and image receptor

Distortion:

•Any misrepresentation of the true size or shape of the patient’s anatomy as demonstrated on the radiographic image

•Two types of distortion

–Size distortion

–Shape distortion

Size Distortion:

•The image is always slightly larger than the actual object size.

•Known as true size distortion, it is minimized by using longer SIDs and minimum OIDs.

Shape Distortion:

•Any misrepresentation of the true shape of the patient’s anatomy

•Also called true distortion

•Controlled by alignment of central ray, patient’s anatomy, and IR

•May be deliberate to deal with superimposed structures

Deliberate Distortion:

•Accomplished by angling or rotating the patient relative to the central ray of the x-ray beam

•Helps overcome superimposition of anatomic structures

Fluoroscopy:

•Use of x-rays to create real-time images of patient anatomy and function

•Requires a radiographic/fluoroscopic (R/F) x-ray system with image intensification

•Physicians are able to observe the body’s physiologic actions

•Images taken during fluoroscopy are digital images

Conclusion:

•Optimizing image quality is a delicate balance among various x-ray imaging parameters.

•Digital detector technology is replacing film-screen technology.

•Digital technology offers greater exposure latitude and lower dose.

•The technologist is responsible for using the lowest exposure necessary to achieve optimum image quality.

Patient Interactions

1.Identify qualities needed to be a caring radiologic technologist.

2.Specify needs that cause people to enter radiologic technology as a profession.

3.Discuss general needs that patients may have according to Maslow’s hierarchy of needs.

4.Relate differences between the needs of inpatients and those of outpatients.

5.Explain why patient interaction is important to patients, as well as their family and friends.

6.Analyze effective methods of communicating with patients of various ages.

7.Explain appropriate interaction techniques for various types of patients.

8.Discuss considerations of the physical changes of aging with regard to radiologic procedures.

9.Discuss appropriate methods of responding to terminally ill patients.

Patient Needs:

•Understand that patients don’t choose to visit the radiology department…necessity dictates their visit.

•They are in an altered state of awareness

•Fear of the unknown is profound

•Fear of loss of control

Maslow's Hierarchy of Needs

•People strive from a basic level of physiologic needs toward a level of self-actualization.

•Each level of needs must be satisfied before an individual proceeds to the next level.

•Patients are often at the lower levels of Maslow’s hierarchy.

Patient Dignity

•Deals with a patient’s self-esteem

•Patients feel a strong loss of power over their fate

•Embarrassing situation that they feel isolates them from others

•Loss of privacy and access to loved ones

•Feelings of guilt on several fronts

Communication if critical to success.

Communication Essentials

•Patient care communication must be patient-focused.

•Communication needs to be accurate and timely.

•Always remember to consider communication and relating with patient’s family and visitors.

•As a technologist, communicate within your Scope of Practice.

Verbal Communication

•Spoken words

•Written words

•Voice intonation

•Slang and jargon

•Organization of sentences

•Humor

Nonverbal Communicacation

•Paralanguage - pitch, tone, rate of speech

•Body Language – eye contact is important

•Touch – support, emphasis and palpation

•Professional Appearance

•Physical Presence posture, facial expressions

•Visual Contact

•Average American reads at the 8th to 9th grade level

•44% of people age 65 and older read at about the 5th grade level or lower

May be necessary to verbally explain examination prep directions or information on consent forms.

Common Patient Types

•Seriously Ill and Traumatized Patients

•Visually Impaired Patients

•Speech- and Hearing-Impaired Patients

•Non–English-Speaking Patients

•Mentally Impaired Patients

•Substance Abusers

Mobile and Surgical Patient Communication

•These unique patient care environments require special patient communication considerations.

•Begin by calling the patient’s name, identifying yourself to the patient, and explaining the procedure.

Communication with Patient Family and Friends

•Professionally introduce yourself.

•Briefly explain the procedure.

•Explain why they must leave the immediate area during the exposure.

Age as a Comminication Factor

•Patient age must be factored into communication techniques.

•Age is not a barrier to effective communication.

Pediatric Patients

•Come down to their eye level to talk.

•Speak softly and less authoritatively.

•Set up equipment before the child enters the exam room.

•Soften room lighting.

•Avoid loud and dramatic equipment movements.

•Use gentle touch.

•Maintain eye contact.

Physical Changes of Functional Aging

•Slowing psychomotor responses

•Slowing of information processing

•Decreased visual acuity

•Decrease in senses

Dealing With Older Patients

•Maintain eye contact.

•Speak clearly and more slowly.

•Speak to them, not away from them.

•Keep them warm if needed.

•Ask permission to touch.

•Demonstrate compassion.

•Ask them what makes them more comfortable.

•Explain thoroughly and keep them informed.

•Treat them with respect and patience.

Terminal Patients

•It is important to understand that death is part of the cycle of life.

•Radiologic sciences professionals often deal with the dying process as part of acute death events.

•Society’s attitudes toward death and dying have changed to become more open and respectful of the terminal patient’s wishes and rights.

•Dying patients and their families and loved ones need to work through the grieving process in a natural and individualized timeframe.

Five Stages of the Grieving Process

1.Denial and Anger

2.Bargaining

3.Depression

4.Preparatory Depression – realization of the inevitable

5.Acceptance

Conclusion

•Communication skills are essential to good medical imaging.

•A good communication process is a closed loop.

•Communication strategies need to accommodate the uniqueness of each patient.

•Patients enter the health care setting feeling vulnerable and outside their comfort zone.

•Medical professionals recognize these feelings and act with compassion and empathy for the patient’s welfare.

•Aging and terminal patients present their own set of patient care challenges.

History Taking

1.Describe the role of the radiologic technologist in taking patient clinical histories.

2.Describe the desirable qualities of a good patient interviewer.

3.Differentiate objective from subjective data.

4.Explain the value of each of the six categories of questions useful in obtaining patient histories.

5.Describe the importance of clarifying the chief complaint.

6.Detail the important elements of each of the sacred seven elements of the clinical history.

Patient History Process

•Look at taking a patient history as an interview of the patient.

•In many cases the radiologic sciences professional is the eyes, ears, and mouth of the radiologist.

•Possessing good history-taking skills is an essential responsibility of the radiologic and imaging sciences professional.

•Information gathered needs to be accurate and specific in detail, if possible.

•Genuine interest in what the patient has to say, attentiveness, and an aura of professional competence can provide patients with a real sense of caring.

Qualities of Interviewer

•Acknowledge patient’s anger, if present

•Respect for patient

•Be genuine

•Empathy (not sympathy) for patient’s condition

•Patients need to feel the information they are providing is important

•Don’t intimidate patients

•Attention to detail

•Accurate note-taking skills

•Good questioning skills

•Multi-tasking, communication skills

•Maintain a polite and professional demeanor

Data Collection Process

•Most patients understand the importance of a history and will provide information as requested.

•Remember, the information needed by the radiologist is specific to the patient’s reason for the examination.

•Never disregard anything the patient says, especially if it does not fit with the opinion you are forming about the patient’s symptoms.

Questioning Skills

•Use open-ended questions.

•Facilitate a response from the patient.

•Remain quiet to get a response.

•Use probing questions to focus in on more detail.

•Repeat patient response to clarify and confirm.

•Summarize to verify accuracy.

Objective Data

•Perceptible to senses

•Able to be measured

•Signs that can be seen, heard, felt, and so on

Subjective Data

•Patient feelings

•Pain level

•Attitude

•Opinion of observer

•Subject to interpretation

Elements of Clinical History

•Chief Complaint

–MDs tend to focus on this.

–Permit the patient to add more than a single complaint when it appears multiple complaints are valid.

–Ignoring all symptoms except the most predominant can cause you to miss other important clinical information.

Sacred Seven of Medical Histories

•Localization

•Chronology

•Quality

•Severity

•Onset

•Aggravating or Alleviating Factors

•Associated Manifestations

Patient History Considerations

•Does patient history data match requisition?

•Do symptoms support exam?

•Verify symptoms with exam request

•How would you describe pain?

–Localized vs. general

–Where

–How long

–Duration

–Old vs. new

Role of Technologist

•Act as good listener

•Take accurate notes and record them appropriately

•Essential responsibility of technologist

•Get answers to key clinical questions

•Present a professional image

•Important role in interacting with patient

•Consider the patient history as an interview with the patient.

•Demonstrate respect, compassion, and empathy for the patient’s condition.

•Clearly identify the patient’s chief complaint.

•Gather all pertinent information relative to the procedure.

•Look for objective and subjective data.

•Present a professional image.

•Take accurate notes with attention to details.

•Never forget, you may be the eyes, ears, and voice of the radiologist with the patient.

Safe Patient Movement and Handling Techniques

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.

Orthostatic Hypotension:

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

Wheelchair Transfers:

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

Standby Assist:

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

Cart Transfers:

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.

teacher at blackboard

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

GOOD LUCK!!!