fluoroscopy Flashcards
used for examination
of moving internal
structures and fluids
fluoroscope
real -time imaging, video imaging and digital fluoroscopy
cineradiography
COMPONENTS OF
FLUOROSCOPE
- X-RAY GENERATOR
- X-RAY TUBE
- IMAGE INTENSIFIER
- FOCUSING LENSES
- VIDEO CAMERA
- CHARGED-COUPLED DEVICE (CCD)
selection of (mA) and (kvp)
X -RAY GENERATOR
Converts electrical energy
provided by the generator
into an x-ray beam.
X-RAY TUBE
Converts incident x-rays
into a minified visible light
image.
IMAGE INTENSIFIER
Used to converge image
FOCUSING LENSES
To record image
VIDEO CAMERA
Capture real-time image and display
CHARGED-COUPLED DEVICE
TYPES OF X-RAY TUBES
Radiographic X-ray Tube
Fluoroscopic X-ray Tube
- attached to an overhead movable crane assembly that permits easy positioning of the tube and aiming of the x-ray beam
Radiographic X-ray Tube
Located under the examining table
Fluoroscopic X-ray Tube
- complex electronic device that receives the image-forming x-ray beam and converts it into a visible light image of high intensity
- Converts the pattern of the x-ray beam into a bright visible light.
- approx 20 cm long
- potential diff is 25,000V
IMAGE INTENSIFIER TUBE
- During fluoroscopy, the Bucky tray is moved to the end of the table
- This leaves an opening in the side of the table about 5 cm
- The opening should automatically be covered with at least
0.25 mm lead (Pb equivalence)
BUCKY SLOT
COVER
- X-rays that exit the patient,
interacts with the__, which is made up of Cesium lodide (Cs). Xrays from __ is converted to visible light.
INPUT PHOSPHOR
- Is a thin metal layer usually
composed of CESIUM and ANTIMONY compounds. - Bond directly to the input
phosphor by a transparent thin
layer of adhesive. - Emits electrons when illuminated
by the input phosphor.
PHOTOCATHODE
- Is the site where the accelerated
electrons interact and produce
light. - Xray-o light
- Made up of Zinc Cadmium Sulfide
OUTPUT PHOSPHOR
- Grown as a tiny needles
and are tightly packed in a
layer approx.
300 micrometer - Each crystal is approx.
5micrometer in diameter.
CESIUM IODIDE (Csl)
- Located at the neck of the image intensifier
- Circular plate with a hole in the middle, so electron can pass through to the phosphor.
- Potential difference; 25, 000 V
- Draws electrons from the photocathode and accelerates them toward the output screen.
ACCELERATING ANODE
- Provide considerably greater flexibility in all fluoroscopic examinations
- Trifield tubes come in various sizes, most common is 25, 17, 12 centimeters
- “__ produce different magnification of the image”
MULTIFIELD IMAGE
INTENSIFICATION
- Dead-man type of exposure
- Bucky opening and protective
curtain is covered with 0.25mm
(Pb) lead
FLUOROSCOPY
- Is like THERMIONIC EMISSION - electron emission that follows the heat stimulation.
- Whereas, ___ is electron emission that follows light stimulation.
PHOTOEMISSION
number of electrons emitted by the
photocathode is ____ proportional to the intensity of the light that reaches it
directly
- This lenses helps prevent diverging of the x-ray beams as they travel cathode to anode.
- This process is also known as
minification - the pattern from large
cathode end of lI tube must be reduced to small output phosphor
ELECTROSTATIC FOCUSING LENS
- Also called “Scattering of light”
- A process that can reduce the contrast of image - intensifier tube.
- Internal scatter radiation in the form of x-rays, electron and particularly light.
VEILING GLARE
X-rays –> light
Input phosphor (Csl)
- Photoemission
- Light –> electron beam
Photocathode
Maintain and minify e
Electrostatic lenses
Attracts e in beam
Anode
e –> light
Output phosphor (ZnS-CdS)
diagnostic technique in which the camera is used to record images of internal body structures produced through radiography fluoroscopy
CINEFLUOROSCOPY
photographic recording of fluoroscope image.
PHOTOFLUOROSCOPY