Radiography Notes

HIPAA

• HIPAA stands for Health Insurance Portability & Accountability Act.

• It protects patient privacy and confidentiality.

• It addresses what information is protected, patient rights, and how information can be used.

Privacy & Confidentiality Policy

• DMIR policy includes "No, No's".

Radiographs & HIPAA

• Radiographs are part of the medical record.

• Ownership of radiographs

• Image maintenance is important.

• The original radiograph

• Patient release of radiographs is a consideration.

Intro to Radiography

• Basics of X-ray Physics

• History of X-ray

• X-ray Tube components:

  • Collimator

  • Bucky

  • Grid

  • Control Panel

History of X-ray Discovery

• Wilhelm C. Roentgen discovered x-rays on November 8, 1895.

X-ray Tube Components

• Glass Envelope:

  • Contains a vacuum to allow electrons to flow without colliding with gas atoms.

  • Made to withstand high temperatures.

• Window:

  • Part of the glass envelope where x-rays pass through on their way to the patient.

  • Made of thinner glass.

• Tube Housing:

  • Contains oil for electrical insulation.

  • Helps keep the tube cool.

• Cathode (Negative Terminal/Electrode):

  • Contains a focusing cup (ring) with a negative charge surrounding the filament.

  • Filament Focusing Cup

• Anode (Positive Terminal/Electrode):

  • Made of tungsten-rhenium, which has a high atomic number and melting point.

  • Attached to a rotor that rotates the disk.

  • Rotor Molybdenum Disk

X-ray Tube Operation

• Prep Button:

  • When pressed, the filament heats up and releases electrons.

  • Electrons gather in a cloud called a space charge and stay there until the exposure button is pressed.

  • If the prep button is depressed too long, electrons repel each other back into the filament.

  • The anode begins to rotate when the prep button is pressed, rotating from 3000 to 20,000 rpm.

• Exposure Button:

  • When depressed, a positive charge is applied to the rotating anode.

  • The positive charge pulls the electrons across the tube.

  • When electrons strike the anode, x-rays are produced.

X-ray Tube Components

• Cathode

• Anodes

Collimator

• Limits x-ray field size to the area of interest.

• Why Collimate?

  • Limits patient’s radiation dose.

  • Reduces scatter x-rays.

  • Always collimate to the part being imaged.

• Scatter x-rays: X-rays that change direction after coming in contact with matter.

Radiation Types

• Primary Radiation: X-rays leaving the tube.

• Remnant Radiation: X-rays leaving the patient.

• Attenuation: Nature of primary x-rays' change.

  • Energy is absorbed by tissue.

• Scatter Radiation: X-rays change direction.

Grid

• Located under the table, above the Bucky.

• Main purpose is to absorb scatter x-rays.

• Most of the remnant x-ray beam (exiting the patient) is allowed to pass through.

• Scatter x-rays are absorbed by the lead strips before reaching the image receptor (IR).

• Bucky: Tray under the table that holds the image receptor (IR).

Focused Grid

• Proper CR to Grid Alignment

• Primary beam

• Scatter X-rays

Control Panel

• Where Technical Factors are Set

• Technique Factors include:

  • $kVp$ (kilovolt peak)

  • $mA$ (milliamperes)

  • Time (milliseconds-seconds)

Technical Factors

• Milliamperes (mA):

  • Controls the amount of current going through the filament.

  • Current = Heat = Electrons (aka thermionic emission).

  • e- e- e- e-

• Exposure Time (s):

  • Controls the length of exposure.

  • Usually measured in milliseconds (or seconds).

• Together, mA & time make mAs. $mA \times seconds = mAs$

  • Example: $400mA \times 0.04 seconds = 16 mAs$

• mAs determines the QUANTITY of x-rays produced.

• mAs = # of x-rays created. So, what does mAs mean to us?

• Kilovolts Peak (kVp):

  • Controls the energy or penetrating power of the x-rays.

  • X-rays need a certain amount of energy or power to get through the body parts and reach the image receptor.

  • penetrating power SHELLI’S ANALOGY:

    • 1 cup of coffee = low energy = no workee!

    • More coffee = higher energy = WORK DONE!!

• kVp determines the QUALITY of the x-rays produced.

• kVp = penetrating power of x-rays penetrating power QUALITY

Technique Chart

• Technique Chart
  ABDOMEN & BLADDER
  STERNUM
  HIP & PELVIS
  VIEW F S KVP MAS VIEW F S KVP MAS VIEW F S KVP MAS AP L L 76 10 RAO L L 66 12 AP L L 72 12
  LOWER LEG
  S-I JOINTS
  TUNNEL VIEW
  VIEW F S KVP MAS VIEW F S KVP MAS VIEW F S KVP MAS AP/LAT S L 68 2 AP/OBL L L 78 15 Beclere L L 64 5

  SHOULDER
  SACRUM & COCCYX
  Camp Cov L L 64 12
  VIEW F S KVP MAS VIEW F S KVP MAS STOMACH AP L L 66 8 AP L L 76 12 VIEW F S KVP MAS

  CLAVICLE & SCAPULA
  LAT L L 86 50 LPO/RPO L L 76 15 VIEW F S KVP MAS THORACIC SPINE LAT L L 80 40 AP L L 66 10 VIEW F S KVP MAS ESOPHAGUS AXIAL L L 68 10 AP L L 76 12 VIEW F S KVP MAS

  RIBS
  LAT L L 80 25 RAO L L 76 12 VIEW F S KVP MAS SWIM L L 82 35 LAT L L 80 40 AP L L 66 15 DECUB ABDOMEN COLON OBL L L 66 25 VIEW F S KVP MAS VIEW F S KVP MAS

  LUMBAR SPINE
  LT LAT L L 76 15 PA L L 76 12 VIEW F S KVP MAS WRIST OBL L L 76 15 AP L L 76 12 VIEW F S KVP MAS LAT L L 84 50 OBL L L 78 15 PA S L 52 6 PA AXIAL L L 80 35

Other Terminology

• Source to Image Receptor Distance (SID):

  • Usually 40 inches.

  • 72 inches used for some upright exams.

• Object to Image Receptor Distance (OID):

  • Part should be as close to Image Receptor as possible.

  • Big OID = Magnified Image

Image Receptor (IR)

• Film/Screen = Cassette & Film (old school)

• Computed Radiography (CR) = Imaging Plate

• Direct Digital Radiography (DDR) = Thin-film Transistor Detector

• Image receptor “captures” the x-rays = IMAGE

Receptor Exposure

• Receptor Exposure is dependent on how many x-rays reach the IR.

• Determines if your image is over or under exposed

• Exposure indicator (i.e. SI#) will indicate your receptor exposure.

Factors affecting Receptor Exposure

• mAs*

• kVp

• OID

• SID

• Grid use

• Filtration

• Collimation

• Anode heel effect

• Patient (size, pathology)

• Brightness controls lightness/darkness of image on monitor

• Post-processing – controlled by WINDOW LEVEL

• Manipulating the image after exposure

Contrast

• Many shades of gray with little difference between each shade Low Contrast (Long Scale of Contrast)

• Few shades of gray with big difference between each shade High Contrast (Short Scale of Contrast)

• Difference between the shades of gray

Factors affecting Contrast

• kVp

• OID

• Grid use

• Filtration

• Collimation

• Patient (size, pathology)

• Contrast Post-processing – controlled by WINDOW WIDTH

• Kilovolts peak (kVp):

  • Controls the energy or penetrating power of the x-rays.

  • X-rays need a certain amount of energy or power to get through the body parts and reach the image receptor.

  • Produces more similar shades of gray = lower contrast

  • kVp determines the QUALITY of the x-rays produced.

Spatial Resolution

• aka Recorded detail

• Sharpness of the object being x-rayed

• Factors affecting Spatial Resolution

  • OID

  • SID

  • Motion

  • Focal Spot Size

  • Patient Factors

Distortion

• Misrepresentation of true size or shape of the object being x-rayed

• 2 Main Types

  • Size distortion (magnification)

  • Shape distortion (foreshortening & elongation)

  • Factors affecting Distortion

    • OID

    • SID

    • Tube angle

    • Patient Factors

Anatomic Position

• R/L

• A/P

Projection vs. Position

• Projection: Path of the central ray

• Position: Patient or body position

• X-ray Tube Enters @ posterior Exits @ anterior = Posteroanterior (PA) Projection Position = Upright

Projection

• Path of the central ray

• Posteroanterior (PA)

• Anteroposterior (AP)

Position

• Patient position

• Upright

Projection

• Path of the central ray

• Lateral

Position

• Patient position

• Left Lateral

Projection

• Path of the central ray

• Posteroanterior (PA) Oblique

Position

• Patient position

• Left Anterior Oblique (LAO)

Projection

*Path of the central ray
*Posteroanterior (PA)

Position

*Patient position vs. Part position
*Patient: Seated; Part: Pronated

Projection

*Path of the central ray

Position

*Part position
*External/Lateral Rotation

Projection

*Path of the central ray
*Lateromedial projection

Position

*Part position
*Lateral Position

Projection vs. Position

*Anteroposterior (AP) Supine or Supinated or Upright
*Posteroanterior (PA) Prone or Pronated or Upright
*Lateral Left or Right Lateral
*Mediolateral Lateral
*Lateromedial Lateral
*AP Oblique Left Posterior Obique (LPO)
*AP Oblique Right Posterior Oblique (RPO)
*PA Oblique Left Anterior Oblique (LAO)
*PA Oblique Right Anterior Oblique (RAO)

Image Display

*PA vs. AP

Image Display

*Laterals

Image Display

*Obliques

Prepping the Room

*Cleanliness
*Organization

What did you see on my x-ray?

*Radiographer's responsibility

Standard Precautions

*Personal Protective Equipment (PPE)
*Hand washing
*Gloving
*HAND WASHING TECHNIQUE WITH SOAP AND WATER
*Wet hands with water to cover all hand surfaces
*Apply enough soap to cover all hand surfaces
*Rub hands palm to palm
*Rub back of each hand with palm of other hand with fingers interlaced
*Rub palm to palm with fingers interlaced
*Rub with back of fingers to opposing palms with fingers interlocked
*Rub each thumb clasped in opposite hand using a rotational movement
*Rub each wrist with opposite hand
*Rinse hands with water
*Use elbow to turn off tap (if no elbow tap available use paper towel to turn off tap)
*Dry thoroughly with a single-use towel
*Hand washing should take 40-60 seconds

Standard Precautions

*SEQUENCE FOR PUTTING ON PERSONAL PROTECTIVE EQUIPMENT (PPE)
*1. GOWN
Fully cover torso from neck to knees, arms to end of wrists, and wrap around the back
Fasten in back of neck and waist
*2. MASK OR RESPIRATOR
Secure ties or elastic bands at middle of head and neck
Fit flexible band to nose bridge
Fit snug to face and below chin
Fit-check respirator
*3. GOGGLES OR FACE SHIELD
Place over face and eyes and adjust to fit
*4. GLOVES
Extend to cover wrist of isolation gown
*USE SAFE WORK PRACTICES TO PROTECT YOURSELF AND LIMIT THE SPREAD OF CONTAMINATION
Keep hands away from face
Limit surfaces touched
Change gloves when torn or heavily contaminated
Perform hand hygiene

Standard Precautions

*HOW TO SAFELY REMOVE PERSONAL PROTECTIVE EQUIPMENT (PPE)
*EXAMPLE 1
*Remove all PPE before exiting the patient room except a respirator, if worn. Remove the respirator after leaving the patient room and closing the door.
*1. GLOVES
Outside of gloves are contaminated!
If your hands get contaminated during glove removal, immediately wash your hands or use an alcohol-based hand sanitizer
Using a gloved hand, grasp the palm area of the other gloved hand and peel off first glove
Hold removed glove in gloved hand
Slide fingers of ungloved hand under remaining glove at wrist and peel off second glove over first glove
Discard gloves in a waste container
*2. GOGGLES OR FACE SHIELD
Outside of goggles or face shield are contaminated!
Remove goggles or face shield from the back by lifting head band or ear pieces
If the item is reusable, place in designated receptacle for reprocessing. Otherwise, discard in a waste container

Standard Precautions

*HOW TO SAFELY REMOVE PERSONAL PROTECTIVE EQUIPMENT (PPE)
*EXAMPLE 2
*Remove all PPE before exiting the patient room except a respirator, if worn. Remove the respirator after leaving the patient room and closing the door.
*1. GOWN AND GLOVES
Gown front and sleeves and the outside of gloves are contaminated!
If your hands get contaminated during gown or glove removal, immediately wash your hands or use an alcohol-based hand sanitizer
Grasp the gown in the front and pull away from your body so that the ties break, touching outside of gown only with gloved hands
While removing the gown, fold or roll the gown inside-out into a bundle
As you are removing the gown, peel off your gloves at the same time, only touching the inside of the gloves and gown with your bare hands. Place the gown and gloves into a waste container
*2. GOGGLES OR FACE SHIELD
Outside of goggles or face shield are contaminated!
If your hands get contaminated during goggle or face shield removal, immediately wash your hands or use an alcohol-based hand sanitizer
Remove goggles or face shield from the back by lifting head band and without touching the front of the goggles or face shield
If the item is reusable, place in designated receptacle for reprocessing. Otherwise, discard in a waste container
*3. MASK OR RESPIRATOR

Procedure Book

*Exam prep
*Radiologist preference
*Views

Patient Motion

*Voluntary vs. Involuntary
*Causes
*Decreasing motion

Patient Instructions

*Explanation
*Talk to your patient
*Honesty
*Contrast studies

Patient Attire

*Exam requirements
*Chest: off from waist up
Abdomen: all but underwear

Patient Attire

*Exam requirements
*Street clothes
*Artifacts
External Internal Anatomic Equipment
Imaging plate
Grid misuse
DR malfunction
*Radiolucent vs. Radiopaque

Handling of Patients

*Comfort
*Safety
Watch the fingers!
Side up on cart
Unattended patient Standing
*Modesty
*Age Specific Competencies
Pediatric Geriatric

Identifying your Patient

*2 identifiers
Last name Birthdate
HIPAA in waiting room

Verifying Order

*Doctor's orders
*Legal issues

Image Identification

*Information included on the image:
Facility
Patient’s Name
DOB and/or Age
Examination Date & Time

Marker Placement

*Basic Rules of Marker Placement
*LEGAL ISSUES
Rules of Marking Anatomy AP/PA body Lateral Decubitus
Obliques Extremities
*Bi-lateral extremities Shoulder or Hip R

Correcting Marking Errors

*Oops…I Marked it Wrong!
*How to correct this error…

Image Receptor Placement

*Sizes
*Placement
Landscape/Crosswise
Portrait/Lengthwise

Image Receptor Placement

*Body Habitus
Chest
Abdomen
Hypersthenic
Sthenic
Hyposthenic
Asthenic

Image Receptor Placement

*Body Habitus
Chest
Abdomen

Collimation vs. Cropping

Collimation vs. Cropping

*Collimation = BEFORE EXPOSURE
*Post-exposure Cropping (aka post-exposure shuttering, electronic collimation, electronic masking)
ASRT Statement
DMIR Program Design, rule #24

Central Ray Angulation

*What is the central ray?
*Why do we angle?
*Cephalic vs. Caudad
Cephalic Caudad

Obese Patients

*Equipment
*Transport
*Patient Transfer
*Technique
*Image Quality
*# of images

Obese Patients

*Light field