computed radiography and digital radiography

DIGITAL PROJECTION
RADIOGRAPHY

COMPUTED RADIOGRAPHY


DIGITAL PROJECTION
RADIOGRAPHY DEPENDS ON
COMPUTER TECHNOLOGY TO
PRODUCE DIGITAL
RADIOGRAPHIC IMAGE


DIGITAL PROJECTION RADIOGRAPHY

COMPUTED RADIOGRAPHY (CR)

DIGITAL RADIOGRAPHY (DR)


DIGITAL RADIOGRAPHY
vs
COMPUTED RADIOGRAPHY


X-RAYS

DR

DETECTORS

ADC

11011101


X-RAYS

CR

CR PLATE
SCANNER

ADC

11011101


COMPUTED RADIOGRAPHY
(CR):
USES PHOTOSTIMULABLE PLATE (IMAGE
PLATE)
INSTEAD OF FILM, AS THE IMAGE
RECEPTOR.
CR USES CASSETTE THAT LOOKS VERY
SIMILAR TO CONVENTIONAL RADIOGRAPHIC
CASSETTE.


CR PLATE !!!!!
DOES NOT USE SCREENS OR

FILM ( CONVENTIONAL FILM)



CR PLATE


CASETTE CONSTRUCTION
►

LIGHTWEIGHT ALUMINUM
PLASTIC

►

STEEL FRAME

►

FRONT PANEL MADE OF LOW ATTENUATION
CARBON FIBER


CR CASSETTES ARE NOT
LIGHT-TIGHT

IMAGE PLATE IS NOT
SENSITIVE TO LIGHT

CR CASSETTE IS
PROTECTING IMAGE PLATE
FROM DAMAGE
+
IS THE STABLE VEHICLE FOR
TRANSPORT AND
PLACEMENT OF THE
CASSETTE UNDER THE
PATIENT


BACK PANEL CONTAINS LEAD
FOIL TO PROTECT THE PLATE
FROM BACKSCATTER


BACK PANEL ALSO CONTAINS
CHIP TO RECORD PATIENT
DEMOGRAPHIC INFORMATION


REMOTE OPERATOR PANEL





IMAGE PLATE

APPROX. 1MM

CROSS-SECTION OF CR
PLATE
PROTECTIVE LAYER
PHOSPHOR LAYER
ANTI-HALO & REFLECTIVE LAYER

BASE

BACKING LAYER


BASE
►

PET- POLYETHYLENE TERAPHTALATE


PHOSPHOR LAYER
►

Ba FX: Eu +2


PROTECTIVE LAYER
►

FLUORINATED POLYMER MATERIAL

PROTECTS PHOSPHOR LAYER


ANTI-HALO LAYER + REFLECTIVE
LAYER
►
►

PREVENTS LASER FROM PASSING THROUGH.
REFLECTED LIGHT FROM PHOSPHOR IS ALLOWED
TO PASS.