Purpose
Image Quality of a new a-Si/CsI X-ray flat panel detector (XFPD) has been compared to the Image Quality of 9" and 12" XRII/CCD imagers (ie: XRII) in the conditions of surgical fluoroscopy and 3D (CBCT) reconstruction.
The advantages of XFPD's are their large detection area,
non distortion,
low sensitivity to magnetic fields,
low weight and compactness.
Different measures were performed on each imager in order to compare their uniformity,
linearity,
spatial resolution and signal to noise performances.
Special care has been taken to compare image...
Methods and Materials
In order to study the image quality performances, the following sensors are used :
(a) the 9" XRII (TH9438QX) with a CCD camera 1000x1000 pixels 30 fp/s 12 bits ADC
(b) the 12"XRII (TH9432QX) with a CCD camera 1000x1000 30 fp/s 12 bits ADC
(c) a Pixium 2630S X-ray Flat Panel Detector (ie: XFPD) with a 28,7 cm by 26,1 cm field of view,
1560 x 1420 pixels matrix size at 30 fp/s 16 bits ADC.
Two types of pixel binning are available which leads...
Results
First,
the BNU index were measured on both type of imager. The BNU index was respectively 11 % and 16% for the 9" and 12" XRIIs.
For the XFPD,
the BNU index was 0,6 % in both binnings 1x1 (pixel size = 0,184 mm) and 2x2 (pixel size = 0,368 mm).
Therefore,
the XFPD shows better uniformity than XRIIs.
The step wedge measures were performed at 4 different doses level (9-18-40-75 nGy) at 70 kVp.
These measures between the 3 image sensors (figure 3) shows...
Conclusion
The image quality comparison between the new a-Si/CSI x-ray flat panel detector and conventional 9" and 12" RIUs demonstrates that non-cooled XFPD has reached similar performances than conventional imagers for Surgical Applications where low dose performance is mandatory.
One could argue that XFPD signal to noise is lower than a conventional XRII.
This is true at the expense of a higher spatial resolution.
Thus, when images are acquired with comparable resolutions (ie: XFPD binning 2x2) and MTF compensation,
bone detail visibility is comparable. Moreover,
as...
References
[1] "Detective quantum efficiency of an x-ray image intensifier chain as a benchmark for amorphous silicon flat panel detectors" A.Koch,
J-M Macherel,
T.
Wirth,
P.
de Groot,
T.
Ducourant,
D.
Couver,
J-P Moy,
E.
Calais.
Proc SPIE Physics of Medical Imaging 4320,
p 115-120,
February 2001.
[2] "Amorphous silicon x-ray image sensor" J.
Chabbal,
C.
Chaussat,
T.
Ducourant,
L.
Fritsch,
J.
Michailos,
V.
Spinnler,
G.
Vieux,
M.
Arques,
G.
Hahm,
M.
Hoheisel,
H.
Horbaschek,
R.
Schulz,
M.
Spahn,
,
in Medical Imaging 1996: Physics of...
Personal Information
Jérémie Pescatore
Thales X-ray Imaging Solutions Components & Subsystems
460 rue du Pommarin 38430 MOIRANS - France
[email protected]
