Canon OMNERA 400A, Operator'S Manual

Page: 145 / 156

Operator´s Manual
0073-095-418-EN Rev. 5.1 OMNERA®
2020-09-25 Page 139
Digital Radiography (DR)
The Digital Radiography Detector is a flat
panel that receives the X-ray image and
converts it to digital information. The Digital
Radiography Detector replaces convention-
al X-ray film and cassettes.
Direct Radiography (DR)
A term used to distinguish the use of a pho-
toconductor-based method as opposed to
the X-ray capture and conversion method
used in a scintillator or phosphor-based
detector.
DR
Digital Radiography/Direct Radiography
E
EMC
Electromagnetic Compatibility
End stop
See Mechanical end stop and Software end
stop.
ESA
Exam Specific Algorithm. Algorithm used to
optimize raw image data for a particular
type of exam.
EXI value
Exposure Index. According to Standard IEC
62494-1: “Exposure index (EI) measures
the detector response to radiation in the rel-
evant image region of an image acquired
with a digital x-ray imaging system.
The exposure index allows the operator to
judge if an image was taken at a detector
exposure level suitable for the intended lev-
el of image quality. It is important to note
that the exposure index, as defined in IEC
62494-1, is derived from the image signal,
which in turn is usually related to the energy
absorbed in the detector, i.e. the detector
dose, but not directly to the air kerma at the
image receptor. The relation to image re-
ceptor air kerma (air kerma at the detector
surface) is introduced only at one radiation
quality through calibration. However, this
definition is appropriate as the image quality
in digital radiography is determined mainly
by the signal-to-noise level, which in turn is
determined by the absorbed energy”
Exposure An image is taken against an imaging unit.
F
Focal Distance
The distance from the source of the X-rays
to the patient.
Appendix A
Glossary