1. Home
  2. Flashcards
  3. Preview

this one

  1. who discovered x-rays and when?
    Wilhelm Conrad Roentgen in November 8, 1895
  2. what are the 3 main parts of an x-ray unit?
    . generator/transformer

    . control console

    . x-ray tube
  3. list the 2 sides of the x-ray tube and specify the charge associated with that side
    . anode is positive

    . cathode is negative
  4. anode is
    positive

    Housing protects and insulates tube
  5. cathode is
    negative

    Filament (-) focusing cup
  6. how many cm are there to 1 inch?
    2.54 cm
  7. what is a detent
    locking mechanism for the SID or table bucky
  8. what are the 4 requirements for x-ray production
    . vacuum

    . source of electrons

    . target for electrons

    . high potential difference between the source and the target
  9. what percentage of the kinetic energy is converted to heat , what percentage is converted to x-ray?
    99% heat

    1% x-ray
  10. what is the smallest unit of EM (electromagnetic energy)?
    photon
  11. define wavelength?
    distance from one crest to the next

    Shorter Wavelengths = more energy & better penetration = longer gray scale

    • Longer Wavelengths = less energy &
    • less penetration = shorter gray scale
  12. define frequency
    number of times per second that a crest passes a given point
  13. three types of x-rays
    . primary

    . scatter(secondary)

    . remnant (exit)
  14. primary x-ray is
    x-ray exiting the tube
  15. scatter (secondary) x-ray
    what not absorbed

    • Once primary beam hits solid matter, what is not absorbed will scatter in many
    • directions
  16. remnant x-ray
    Remainder of the primary been after its been attenuated

    Pattern of intensity is what creates the radiographic image
  17. define absorption
    absorb like a sponge, soaks up the whole beam No exit of beam
  18. attenuated
    absorption of the x-ray beam
  19. exit radiation
    the beam that passes through the patient and exposes the film is called exit radiation

    the exit radiation is what creates the image
  20. white image on film is
    what was absorbed
  21. black image on the film is
    what was exposed
  22. shades of gray on the film
    what was attenuated
  23. latent image
    THE INVISIBLE IMAGE ON AN EXPOSED FILM OR PSP PRIOR TO PROCESSING
  24. manifest image
    A VISIBLE IMAGE AFTER PROCESSING
  25. what are 5 radiographic factors
    . time(s)

    . Milliamperes (mA)

    . Millampere per second (mAs)

    . Kilovoltage peak (kVp)

    . Distance
  26. define time(s)
    • Duration of the exposure of
    • radiation

    • Effect on Film
    • Longer exposure Time will increase
    • Density of Film & Patient Exposure

    Shorter exposure Time will decrease Density of Film & Patient Exposure
  27. define mA (Milliamperes)
    • Quantity of Current to the
    • Filament

                    Milliamperage

    • Measure of the current flow rate in the
    • x-ray tube circuit and is directly proportional to the tube current.

    • Determines the number of electrons
    • available to cross the tube  (current
    • doubles=electrons double).

    • Determines the rate at which x-rays are
    • produced.

    Increase in mA will decrease total exposure time and result in less motion blur.

    Decrease in mA will increase total exposure time and result in more motion blur.
  28. define mAs (milliamperes per second)
    Quantity of  radiation exposure

    • Product of  tube current (mA) and
    • time (s).

    mAs = mA x s

    Controls total amount of radiation exposure

    Increase in mAs  will increase Density and Patient Exposure

    • Decrease in mAs will
    • decrease Density and Patient exposure
  29. define kVp kilo-voltage peak
    Controls Energy of Radiation Beam

    Kilovoltage peak is the measure of the POTENTIAL difference across the x-ray tube. 

    It determines the speed of the electrons in the electron stream.

    It determines the energy of the x-ray beam
  30. define SID
    source to image receptor distance
  31. define SOD
    source to object distance
  32. define OID
    object to image receptor distance
  33. what are the 3 different measure of distance
    • SID
    • SOD
    • OID
  34. what is the purpose of a back-up timer when using AEC
    Safety Devise Used with AEC to Prevent Over-Exposure of Radiation to the Patient
  35. what is density
    The amount of blackness of an image

    Also known as optical density

    Controlled by mAs

    Increase mAs = increase blackness

    Decrease mAs = decrease blackness
  36. Four Principles in Image Quality
    Density

    Contrast

    Detail

    Distortion
  37. what is contrast
    • The degree of difference between
    • the light and dark areas of an x-ray

    • High contrast =  more black and white
    •  
    • Low contrast = overall gray appearance

    Controlled primarily by kVp
  38. contrast is controlled by
    kVp
  39. density is controlled by
    mAs
  40. what is recorded detail
    The degree of sharpness of a structural line on an x-ray
  41. the main factor that affected detail is
    size and focal spot
  42. what is distortion
    • Refers to a variation in the size and/or shape of the image in comparison to the
    • object it represents.
  43. what are the two types of distortion
    size affected by OID

    shape affected by angulation of table or part
  44. what is the main factor that controls distortion
    OID object to image receptor distance
  45. what does ALARA stand for
    As low as reasonably achievable

    • your goal is to keep all exposures of
    • radiation to the patient
  46. what are the most common of cassettes in inches
    8 x 10

    10 x 12

    14 x 17
  47. what are the 3 cardinal rules for radiation safety
    1.TIME

    2.DISTANCE

    3.SHIELDING
  48. Radiation Safety
    1.TIME Decrease time will decrease exposure

    2.DISTANCE Inverse square law

    • 3.SHIELDING
    • Lead aprons
    • Thyroid Shields
    • Gonad Shields
  49. Inverse Square Law
    • The intensity of the radiation is INVERSELY proportional to the SQUARE of the
    • Distance

    Radiation exposure is inversely (opposite) to the distance squared
  50. what is a dosimeter
    Device for monitoring radiation exposure
  51. where is the dosimeter worn
    Worn at collar level outside of lead apron.
  52. TLD
    thermoluminescent dosimeter (read by heat)
  53. what type of dosimeter do we wear in x-ray
    OSL-optically stimulated luminescence (read by laser)
  54. what is the maximum radiation dose for an occupationally exposed person 18 years age and older
    • For X-ray Techs, the maximum radiation dose per year is 5 rem or
    • 50mSv
  55. what is the most critical period during pregnancy to be exposed to radiation
    first trimester
  56. Anatomic Position
    • Refers to the pt. standing erect with the face & eyes directed forward, arms
    • extended by the sides with the palms of the hands facing forward, heels
    • together, and toes pointing anteriorly.

    • Professionals in medicine always describe the body, a body part, or movement as though it
    • were in anatomical position
  57. Anatomy is the study of
    science of the structure of the body
  58. Physiology is the study of
    study of the function of the body organs
  59. Sagittal Plane
    • Divides the entire body or any part of
    • the body into right & left segments
  60. Coronal Plane
    • Divides the entire body or a body part
    • into anterior & posterior segments

    • Passes from one side to the other (right
    • to left or left to right)
  61. Midsagittal Plane
    Divides the body into EQUAL right & left halves
  62. Midcoronal Plane
    • Passes through the midline of the body,
    • dividing it into EQUAL
    • anterior & posterior halves

    • Often referred to as the Midaxillary
    • Plane
  63. Horizontal Plane
    • Passes crosswise through the body or a body part at
    • right angles to the longitudinal axis

    Divides the body into superior & inferior portions

    Referred to as a transverse or axial plane
  64. Longitudinal Plane
    • Runs lengthwise in the direction of the long axis of the body or any of its parts
    • (regardless of its position)
  65. cephalic
    towards the head
  66. caudal
    away from the head
  67. distal
    posterior away
  68. proximal
    anterior towards the source
  69. lateral
    referring to the side
  70. medial
    towards the center
  71. decubitus
    horizontal ray laying down
  72. projection
    the path of the CR from the radiographic tube and through the patient to the IR
  73. what anatomy makes up the mediastinum
    • heart
    • great vessels
    • trachea
    • esophagus

    NOT the lungs
  74. what are the 4 chambers of the heart
    • 2 ventricals
    • 2 atria
  75. how many lobes does the left lung have
    2
  76. how many lobes does the right lung have
    3
  77. carina
    the trachea divides into right and left primary branches at the carina tracheal bifurcation
  78. what are the two projections of the chest x-ray
    PA and Lateral

    PA the heart is closest to the IR
  79. SID used for the chest x-ray
    72 reduces magnification
  80. what respiration is used in chest x-ray
    2nd and hold
  81. what body plane is centered / perpendicular to the IR for the PA chest
    midsagittal T7
  82. what body plane is centered / perpendicular to the IR for the lateral chest
    midcoronal T7
  83. why do we have the patient to roll their shoulders forward for PA chest
    rotate the scapula out of the lung field
  84. how many posterior ribs should be seen on a PA chest
    10
  85. how can you tell if a PA chest has rotation to it
    if space between clavicle  and manubrium space
  86. what projection should be used if the patient is unable to stand for a chest exam
    decubitus to view air fluid levels
  87. what is the anatomy of interest for the lordotic chest x-ray
    apices of the lungs without super clavicles
Author
139shay
ID
282341
Card Set
this one
Description
this one
Updated

  1. Home
  2. Flashcards
  3. Preview