radiographic procedure 1 intro

• Exposure factors/parameters and image characteristics

  • kVp
  • mA
  • time (s)

  
• Image formation

  1. X-ray diverges from a point source

  2. Travel in straight lines

  3. Able to affect a photographic emulsion

  4. Any object in the x-ray path casts a shadow which can be recorded on the photographic material as an image

  
• kVp


  The power and strength of the x-ray beam (quality of the x-rays)

  
• mA


  The number of x-ray photons produced by the x-ray tube at the setting selected (quantity of x-rays)

  
• time (s)


  How long the exposure lasts
• Technique chart

  Developed to list average kVp, mA, time, distance, and film type used for various exams
• Concepts of Radiography


  • Minimum of 2 projections for complete examination
  • Long axis of the body part should be aligned with the long axis of the cassette EXCEPT when we need to include the length of the structure

  
• Evaluation Criteria


  • Parts that should be seen on a radiograph to indicate that the radiographic examination is done accurately in terms of positioning and technical factors
  • Radiographer's mission is to obtain an optimum image which can be evaluated against a definable standards known as "Evaluation Criteria"

  
• Positioning Accuracy

  • Cassette usage
  • Central ray (CR) should pass through the center of the part to the center of the film
  • Oblique & axial projections require the beam to be angled to align the part
  • Source-to-Image Distance (SID) = 100 cm on most table examination
  • Part placement on cassette should include all interested anatomy within the collimated borders

  
• Film markers and Patient Identification

  • Proper ID on all images including lead markers and name/patient ID area
  • Anatomical markers to indicate the side of the body part

  
• Radiographic Quality

  Refers to the physical characteristics of the body, including shape, size, muscle tone and position of the internal organs

  
• Body Habitus

  • Hypersthenic
  • Sthenic
  • Hyposthenic
  • Asthenic
• Surface Landmarks

  • A groove or prominence on a bone that serves to the location of other body structures
  • Important surface landmarks and their corresponding vertebrae level

  
• Radiographic procedure

  The process and procedures of producing radiograph
• Radiograph


  An image of patient's anatomic part, as produced by the action of x-rays on an image receptor
• Image receptor


  The devices that captures the radiographic image; refers to both film/screen cassettes and to digital acquisition devices
• Central ray

  The center-most portion of the x-ray beam emitted from the x-ray tube
• Anatomic position

  An upright position with arms adducted (down), palm forward, head and feet directed straight ahead
• Body planes


  • Sagittal plane
  • Coronal plane
  • Horizontal (axial) plane
  • Oblique plane

  
• Sagittal plane


  Any longitudinal plane that divides the body into right and left parts
• Midsagittal


  A midline sagittal plane that divides the body into equal right and left parts, passing approximately through the sagittal suture of the skull
• Coronal plane


  Any longitudinal plane that divides the body into anterior and posterior parts
• Midcoronal


  Divides the body into approximately equal anterior and posterior parts, passing approximately through a coronal suture of the skull
• Horizontal (axial) plane


  Any transverse plane that passes through the body at right angles to a longitudinal plane, dividing the body into superior and inferior portions
• Oblique plane


  A longitudinal or transverse plane that is at angle or slant and is not parallel to the sagittal, coronal or horizontal plane
• Base plane of skull

  A transverse plane formed by connecting the lines from the infraorbital margins to the superior margins of the external auditory meatus (EAM), sometimes called the Frankfort horizontal plane
• Occlusal plane


  A horizontal plane formed by the biting surfaces of the upper and lower teeth with jaws closed, used as a reference plane of the head for cervical spine and skull radiography
• Anterior or Ventral


  The front half of the patient or part that is seen when viewed from the front
• Posterior or Dorsal


  The back half of the patient, or that part of the body seen when the person is viewed from the back
• Lateral


  The side of the body, can be right or left
• Plantar


  The sole or posterior surface of the foot
• Dorsal (Foot)


  The top or anterior surface of the foot (dorsum pedis)
• Dorsal (Hand)


  The back or posterior aspect of the hand (dorsum manus)
• Palmar


  The palm of the hand
• Radiographic projection


  A positioning term that describes the direction of path of the central ray of the x-ray beam as it passes through the patient, projecting an image onto the image receptor
• Posteroanterior (PA) projection


  A projection of the central ray from posterior to anterior, the central ray enters at the posterior surface and exits at the anterior surface
• Anteroposterior (AP) projection


  A projection of the central ray from anterior to posterior, the opposite of PA, the central ray enters at an anterior surface and exits at the posterior surface
• Lateral projection


  Central rays enter at one side and exit at the opposite side, for torso named for the side nearest the film, for limbs named for aspect of structure the central ray entered, then exited
• Right lateral projection


  Central rays enter the left side and exit the right side
• Left lateral projection


  Central rays enter the right side and exit the left side