Fundamentals of Imaging

RAD 206

Image Production

Fluoroscopic Imaging system

Fluoro : fluorescent screen

Scope : viewing; look at carefully; scan; assess or investigate something.

Microscope , telescope , arthroscopy, endoscope, kaleidoscope, stethoscope

Fluoroscopyis an imaging technique that uses X-rays to obtain real-time moving images.

Fluoroscopic Imaging system

Conventional Image intensifier

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1000 light photons at the photocathode from 1 x-ray photon Output phosphor = 3000 light photons (3 X more than at the input phosphor!) This increase is called the flux gain FLUX GAIN 

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Fluoroscopic Imaging system

Digital (DDR / Flat Panel)

• AMORPHOUS SILICON (indirect) X-ray photon to light photon to electron

• AMORPHOUS SELENIUM (direct = No light) X-ray photon to electron

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Direct Capture

Indirect Capture

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CCD Array with a scintillation phosphor 

Fluoroscopic Imaging system

Digital (CCD Array )3

Charge-Coupled Device CCD, which is the light-sensing element. The CCD is a silicon-based semiconductor has three principal advantageous imaging characteristics: sensitivity, dynamic range, and size.

Fluoroscopic Imaging system

Digital (CCD Array )3

Display Types CRT : Cathode Ray Tube

LCD : Liquid Crystal Display

Plasma Display

LED : Light Emitting Diode

OLED , AMOLED , EPD (electrophoretic display)

Things to note Over-Couch tube Under-Couch tube

Under-couch tubes produces lesser scatter radiation that reaches the staff

Reducing the OID produces lesser scatter radiation that reaches the staff

Digital Abbreviations/ Acronyms