PHILIPS MEDICAL SYSTEMS DMC imaging_plates-velara.doc Oct – 17 - 2003 page 1-1
Computed Radiography, e.g. PCR or other imaging plates
Dose Rate Control setting Velara
Instead of programming IMAGING PLATE for Screens and IMAGING PLATES for Films in a later release of
Velara one can select any of the following screens since they have the same kV characteristic (for a 400
speed system):
AGFA MR 400
KODAK X-OMAT.Rapid
MAVIG SE-4
MCI OPTON.R.BlueFast
REGO NP 400
For the film program :
X-CONSTANT RLF=1
Abbreviation: Any name up to six characters can be given. The abbreviation name should indicate the
programmed speed type if different speeds shall be used with the same imaging plates.
Dose of FSC [µGy]: Use K
explanation this page. The value can be adapted to the local "density taste".
s
Formula to determine the speed = S of a film-screen-combination:
K0 1000 µGy >> use speed as !! S = speed must not be mixed up !!
S = ------- = --------------------------- >> abbreviation !! with S = sensitivity PCR !!
K
is a constant with a value of 1000 µGy.
K
0
K
is a variable value principally representing a switch off dose to obtain a density of 1.0 above base and
s
If e.g. Ks = 5 µGy (like the example of the previous page)
1000 µGy
S = = 200
5 µGy
Range of speed values S within the standard speed class SC systems:
More information, e.g. for films and screens not appearing in the selection list during programming, are
available in booklet "Radiographic screens and films", manual order No. 4512 980 50592.
Dose of FSC [µGy]: >> name
s
fog, (normal films determined by the manufacturer of a film-screen system for defined processing
conditions which are different in a computed RAD system). Can be adapted to the local "density taste"
only valid for film-screen-combinations for an optical density of 1.0
Speed class SC
Standard
dose / exposure [µGy]
Standard class SC
Speed value S
Range
6 167 5 - 9
12 83 10 - 18
25 40 20 - 36
50 20 40 - 71
100 10 80 - 140
200 5 160 - 280
400 2.5 320 - 560
800 1.25 630 – 1100
1600 0.625 1250 – 2200