Flouroscopy
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Transcript of Flouroscopy
Fluoroscopy
• Fluoroscopy is a type of medical imaging that shows a real time X-ray image on a monitor, much like an X-ray movie.
• During a fluoroscopy procedure, an X-ray beam is passed through the body.
Image intensifier:
• The image-intensifier tube is a complex electronic device that receives the image-forming x-ray beam and converts it into a visible-light image of high intensity.
• Within an image intensifier, the input phosphor converts the
x-ray photons to light photons, which are then converted to photoelectrons within the photocathode
Image intensifier
• Through this process, several thousand light photons are produced for each x-ray photon reaching the input phosphor.
• Most modern image intensifiers use cesium iodide for the input phosphor because it has a high absorption efficiency and thus decreases patient dose.
Image-intensifier tube• The image-intensifier tube is approximately 50 cm long. A
• potential difference of about 25,000 V is maintained across the tube between photocathode and anode so that electrons produced by photoemission will be accelerated to the anode
Photocathode
• The photocathode emits electrons when illuminated by the input phosphor.
ANODE:• The anode is a circular plate with a hole in the middle through which
electrons pass to the output phosphor, which is just the other side of the anode .
Advantage of Image intensifier
• The principal advantage of image-intensified fluoroscopy over earlier types of fluoroscopy is increased image brightness. this requires high levels of image brightness.
• The image intensifier was developed principally to replace the conventional fluorescent screen, which had to be viewed in a darkened room.
FLUOROSCOPIC DATA AQUSITION-IMAGE INTENSIFIED SYSTEM
1. X-RAY TUBE2. PATIENT3. IMAGE INTENSIFIER4. OUTPUT PHOSPHOR5. CAMERA6. MONITOR
IMAGE
The solid state charge-coupled device (CCD).
• Two methods are used to electronically convert the visible image on the output phosphor of the image intensifier into an electronic signal:
Thermionic television camera tube
Applications
Fluoroscopy is used in many types of examinations and procedures such as
• cardiac catheterization
• Arthrography (visualization of a joint or joints)
• lumbar puncture,
• placement of intravenous (IV) catheters (hollow tubes inserted into veins or arteries)