performance comparison of different dr detectors using … · 2017-05-03 · performance comparison...
TRANSCRIPT
Performance Comparison of Different DR Detectors Using
Simplified eDQE Approach
Dogan Bor1, Ahmet Guven2, Turan Olgar1, Ozlem Birgul2
1 Ankara University, Faculty of Engineering, Department of Physics Engineering2 Ankara University, Institute of Nuclear Sciences, Department of Medical Physics.
OBJECTİVE
Simplification of eDQE formalism by excluding the beam stop measurements
Comparison of different system performance in terms of eDQE
Use of eDQE for the optimization of clinical image qualities
DETECTIVE QUANTUM EFFICIENCY-DQE
RQABeam quality
Detector
0
0,2
0,4
0,6
0,8
1
0 1 2 3 4
MT
F
freq (mm-1)
1,0E-07
1,0E-06
1,0E-05
1,0E-04
0 1 2 3 4
NN
PS
freq(mm-1)
0
0,2
0,4
0,6
0,8
0 1 2 3 4
DQ
E
freq(mm-1)*IEC-62220-1
W Edge phantom10x10x1 mm
IonChamber
DQE (f) = MTF(f)2
NNPS (f) . K.q
Physical performance of the detector
EFFECTIVE DETECTIVE QUANTUM EFFICIENCY- EDQE-
0
0,2
0,4
0,6
0,8
1
0 1 2 3 4
eMT
F
freq(mm-1)
1,0E-07
1,0E-06
1,0E-05
1,0E-04
0 1 2 3 4
eNN
PS
freq(mm-1)
*Samei et al Med. Phys. 2009
Detector
Grid10:1, 40 lp/mm
0
0,05
0,1
0,15
0,2
0 1 2 3 4eD
QE
freq(mm-1)
IonChamber
eDQE (f) = MTF(f)2 (1 – SF)2
NNPS (f) . TF. K.q
Performance of the system as a whole
INCLUSION OF SCATTER DATA TO THE MTF
Use of Beam Stop Technique
SF =PVAtten.
PVBackg.
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1
0 0,5 1 1,5 2 2,5 3 3,5 4
MTF
freq(mm-1)
MTF no scatter
MTF x (1-SF)
-0,2
0
0,2
0,4
0,6
0,8
1
-30 -20 -10 0 10 20 30
LSF for different ROI size
50mm
40mm
30mm
20mm
10mm
0
0,2
0,4
0,6
0,8
1
0 0,5 1 1,5 2 2,5 3 3,5
MT
F
freq(mm-1)
10mm(roi)
20mm(roi)
30mm(roi)
40mm(roi)
50mm(roi)
INCLUSION OF SCATTER DATA TO THE MTF
NHSBSP OBJ_IQ (NW. Marshall)
• No truncation and windowing of LSF• Include all the tail of LSF with a large ROI• No normalization of the zero frequenc to unity for MTF
0
0,2
0,4
0,6
0,8
1
0 1 2 3
MT
F
freq(mm-1)
10cm PMMA
0
0,2
0,4
0,6
0,8
1
0 1 2 3
MT
F
freq(mm-1)
25cm PMMA
0
0,2
0,4
0,6
0,8
0 1 2 3
eD
QE
freq(mm-1)
10cm PMMA
0
0,2
0,4
0,6
0,8
0 1 2 3
eD
QE
freq(mm-1)
25cm PMMA
SF = 0.38
SF = 0.44
IncreasingROI size (mm)
1020..
70
COMPARISON OF TWO TECHNIQUE
Systems Kodak DRX-1 Kodak DRX-1C Toshiba FDX4343RPhilips l Pixium
4600
Conversion
phosphorGd2O2S:Tb CsI CsI CsI
Pixel area 35x43cm 43x43cm 43x43cm
Pixel matrix 2544x3056 3072x2560 3008x3072 3001x3001
Pixel pitch 139µm 143µm 143µm
Grid type Stationary Stationary Moving
Grid ratio 10:1 12:1 12:1
Focal spot
size(mm)2.0 1.2 1.2 1.2
TECHNICAL CHARACTERISTICS OF THE FOUR SYSTEM EVALUATED
90 kVp, 25 cm PMMA, AEC control, AK measurements in the Bucky
ACQUISITION GEOMETRIES
IEC Methodology Low scatter, focus unsharpness (G2)
Scatter + focus un harpness (G3)Beam hardening filtering (G1)
SIGNAL TRANSFER PROPERTY-STP
1,0E+02
1,0E+03
1,0E+04
1,0E+05
0,0 5,0 10,0 15,0
Pix
el v
alu
e (L
og
axe
s)
Detector Dose(uGy)
STP-RQA7(IEC geometri)
DRX-1C
DRX-1
Toshiba
Pixium 46001,00E+02
1,00E+03
1,00E+04
1,00E+05
0,00 2,00 4,00 6,00 8,00 10,00
Pix
el v
alu
e (L
og
axe
s)
Detector Dose(uGy)
STP-90kVp_G1
DRX-1C
DRX-1
Toshiba
Pixium 4600
Signal Transfer Properties Functions
Systems RQA Geometry G1 Geometry
DRX-1C y=435.62ln(K)+1166 y=515.71ln(K)+947.45
DRX-1 y=442.29ln(K)+1180.9 y=416.89ln(K)+1071.6
Toshiba FDX4343R y=164.83K+53.535 y=144.87K+56.106
Pixium 4600 y=2509.9ln(K)+14450 y=2560.8ln(K)+14593
MTF RESULTS FOR DIFFERENT DIGITAL RADIOGRAPHY SYSTEMS
0,0
0,2
0,4
0,6
0,8
1,0
0 1 2 3 4 5
MT
F
freq(mm-1)
DRX-1C(4.99µGy)
DRX-1(4.7µGy)
FDX4343R(4.7µGy)
Pixium 4600-II(6.44µGy)
RQA7
G3G1
0,0
0,2
0,4
0,6
0,8
1,0
0 1 2 3 4 5
eMT
F
freq(mm-1)
DRX-1C(4.87µGy)
DRX-1(4.39µGy)
FDX4343R(5.4µGy)
Pixium4600-II(8.16µGy)
0
0,2
0,4
0,6
0,8
1
0 1 2 3 4 5
MT
F
freq(mm-1)
DRX-1C(5.64µGy)
DRX-1(5.17µGy)
FDX4343R(12.79µGy)
Pixium 4600-II(9.44µGy)
NNPS RESULTS FOR DIFFERENT DIGITAL RADIOGRAPHY SYSTEMS
1,0E-07
1,0E-06
1,0E-05
1,0E-04
0 1 2 3 4
NN
PS
freq(mm-1)
DRX-1C(5.64µGy)
DRX-1(5.17µGy)
FDX4343R(5.06µGy)
Pixium 4600-II(4.6µGy)
1,0E-07
1,0E-06
1,0E-05
1,0E-04
0 1 2 3 4
eNN
PS
freq(mm-1)
DRX-1C(4.87µGy)
DRX-1(4.39µGy)
FDX4343R(5.4µGy)
Pixium4600-II(5.09µGy)
RQA
G3G1
1,0E-07
1,0E-06
1,0E-05
1,0E-04
0 1 2 3 4
NN
PS
freq(mm-1)
DRX-1C(4.99µGy)
DRX-1(4.69µGy)
FDX4343R(4.7µGy)
Pixium 4600-II(5.12µGy)
DQE-EDQE RESULTS FOR DIFFERENT DIGITAL RADIOGRAPHY SYSTEMS
0
0,2
0,4
0,6
0,8
0 1 2 3 4
DQ
E
freq(mm-1)
DRX-1C(5.71µGy)
DRX-1(5.17µGy)
FDX4343R(5.06µGy)
Pixium 4600-II(4.66µGy)
0,0
0,2
0,4
0 1 2 3 4
eDQ
E
freq(mm-1)
DRX-1C(4.87µGy)
DRX-1(4.39µGy)
FDX4343R(5.4µGy)
Pixium 4600-II(5.09µGy)
0,0
0,2
0,4
0,6
0,8
0 1 2 3 4
DQ
E
freq(mm-1)
DRX-1C(4.99µGy)
DRX-1(4.69µGy)
FDX4343R(4.7µGy)
Pixium 4600-II(5.12µGy)
RQA
G3G1
COMPARISON OF THREE GEOMETRIES FOR DRX -1C SYSTEM
0
0,2
0,4
0,6
0,8
1
0 1 2 3 4
MT
F
freq (mm-1)
G1-90kVp-(4.99µGy)
G2_LF-90kVp-(4.99µGy)
G2_SF-90kVp-(4.99µGy)
G3_90kVp-(4.87µGy)
0
0,2
0,4
0,6
0,8
1
0 1 2 3 4
eDQ
E
freq(mm-1)
G1_90kVp-(4.99µGy)
G2_LF-90kVp-(4.99µGy)
G2_SF-90kVp-(4.99µGy)
G3_90kVp-(4.87µGy)
Optimization of clinical image quality
CONCLUSION
Could we do some standardization for eDQE ?
Could we simplify the eDQE procedure ?
Optimization of the clinical techniques
Comparison of the clinical performance of different systems
Reliable definition of speed for digital system
Why to measure the eDQE ?
Thank you