Arts and Sciences CT The noise reduction effect of the picture which used the quantum noise rejection filter for the filtered back projection in low dose CT photography 1 39496 1 18285 1 56588 1 551 1 42418 1 19999 2 1 2 Key words: 1. Filtered Back Projection FBP 2. Adaptive Iterativre Dose Reduction 3D AIDR-3D 3. Quantum Denoising Software QDS Summary This research is using a quantum noise rejection filter; Quantum Denoising Software It is considered as the QDS method below for Filtered Back Projection It is considered as the FBP method below in CT inspection, and is examination about whether the fall of an exposure dose is possible for not spoiling the noise reduction effect. Picture standard deviation defines standard dose photography as the exposure dose used as 10.0HU. Low dose photography defined it as that in which standard dose photography carried out the dose fall 40%. FBP of standard dose photography evaluated the noise characteristic and low contrast detection ability in the picture and the picture belt Adaptive Iterative Dose Reduction It is considered as the AIRD-3D method below picture which used QDS for FBP of low dose photography. The result in which the picture which used QDS for FBP is almost more equivalent to the FBP picture of standard dose photography and an AIRD-3D picture than the result of the noise characteristic and low contrast detection ability was obtained. The fall of the exposure dose was possible for as a result not spoiling the noise reduction effect. CTFiltered Back Projection FBP Quantum Denoising Software QDS 10.0HU 40%FBP FBP QDSAdaptive Iterative Dose Reduction AIDR-3D FBP QDS FBP AIDR-3D 1 CT CT 1 CT FBP 2 Makoto Fujiwara 1 39496, Takao Yoshiura 1 18285 Yusuke Syutoh 1 56588, Kenji Ooshima 551 Yukihiro Okugawa 1 42418, Megumi Takano 1 19999 Hirofumi Zaizen 2 1, 2 JA Oita Koseiren Tsurumi Hospital FBP 3 4 Model-Based Iterative Reconstruction MBIR 4 5 FBP CTFBP FBP 27 1543
1 kv ma sec/rot PF mm FBP 120 250 1.0 0.938 5 FC12 FBP+QDS 120 150 1.0 0.938 5 FC12 AIDR-3D 120 150 1.0 0.938 5 FC12 2 16 MDCT Alexion16 320mm FOV-M Catphan CTP515 RadiForce R31 3M EIZO NANAO 3423 HIOKI NPS CTWS 3 3-1 32cm FOV-M Catphan CTP515 Catphan 16 MDCT Alexion16 CT SD mas CT SD 10.0HU 6 FBP SD 10.0HU mas 120kV mas SD 250mAs FBP 40% 150mAs 1 512 5120.625mm 0.625mm 3-2 CT Quantum Denoising Software QDS 7 FBP QDS 2 3mm 3Q-00 Q-01 Q-021 5mm2 QDS QDS Q-01 CT Adaptive Iterative Dose Reduction 3D AIDR-3D 8 AIDR-3D 4weak mild std str AIDR-3D mild 28 1544 2014. vol.61 no.746
CT Arts and Sciences a b c 8cm 8cm 1 a FBP bfbp+qds caidr-3d 2 SD ROI 3-3 SD 9 NPS 10 SD 1 1 FBP FBP QDS FBP+QDSAIDR-3D 2 20mm 20mm ROI 1 8cm 2 2 5 SD 5 SD 11 NPS 12 NPS SD 256 256 ROI 1 32 ROI 256 32 8 NPS 8 NPS NPS NPS NPS CTWS 13 3-4 Catphan 1 Catphan supra-slice 14 3 supra-slice1000hu 1.0% 0.5% 0.3% 29 1545
a b c 3 Catphan a FBP bfbp+qds caidr-3d d supra-slice 0.5% 48.0HU ベース部 43HU 0.3% 45HU 1.0% 53.0HU d CT 43.0HU3 CT 1.0%53.0HU 0.5% 48.0HU 0.3%45.0HU 9 15.0mm 9.0mm 1.0mm 2.0mm Catphan 1536 2048250cd/m 2 400 1 DICOM 250HU100HU 50lx 50cm 15 146 35 18.8 supra-slice 1.0% 0.5% 0.3% 9 Catphan FBPFBP+QDS AIDR-3D 60 30 16 t 17 5% 4 4-1 SD 2 FBP+QDSAIDR-3D SD 10.20HU10.50HU SDFBP 30 1546 2014. vol.61 no.746
CT Arts and Sciences SD 10.24HU FBP+QDS AIDR-3D SD FBP SD NPS 4 FBP+QDSAIDR-3DNPS 2 SD mas Noise Power Spectrum (mm 2 ) 1000 100 10 1 0.1 CTDIvol mgy FBP のみ FBP+QDS AIDR-3D 0 0.2 0.4 0.6 0.8 1 Spatial Frequency(cycles/mm) 4 NPS SD HU FBP 250 28.3 10.24 FBP+QDS 150 16.3 10.20 AIDR-3D 150 16.3 10.50 0 0.8cycles/mm FBP FBP+QDS AIDR-3D 0 0.4cycles/mm FBP NPS 0.4 0.8cycles/mm FBP+QDS AIDR-3D NPS 4-2 5 1.0% 0.5% 0.3% FBP 7.71 0.61 6.93 0.47 3.50 1.09 FBP+QDS 7.36 0.74 7.00 0.96 2.79 0.58 AIDR-3D 7.21 0.80 6.93 0.92 2.79 0.80 1.0% 0.5% 0.5% 0.3% FBP+QDSAIDR-3D P =0.63 0.5% P=0.06 P=1.00 P=0.09 P=0.18 P=0.63 P=0.81 P=0.84 P=0.07 P=1.00 8.00 8.00 8.00 6.00 6.00 6.00 4.00 4.00 4.00 2.00 2.00 2.00 0.00 FBP のみ FBP+QDS AIDR-3D 0.00 FBP のみ FBP+QDS AIDR-3D 0.00 FBP のみ FBP+QDS AIDR-3D a b c 5 FBPFBP+QDS AIDR-3D a1.0% b0.5% c0.3% 31 1547
P =0.81 1.0% 0.3% P =0.06 5 FBP+QDS AIDR-3D SD 2 FBP 10.0HU 40% FBP QDS AIDR-3D SD 4 NPS FBP+QDS AIDR-3DNPS FBP NPS CT 1.0cycles/mm 18 NPS 10 FBP NPS FBP NPS QDS AIDR-3D FBP+QDSAIDR-3D 5 5 c 0.3% P =0.07 0.3% 3.03 3 8mm NPS 40% 19 SDFBP 40.0HU AIDR-3D SD 17.0HU CT 6 MTF 20 6 FBPFBP +QDS AIDR-3D FBP+QDSAIDR-3DSD NPSSD FBP NPS FBP+QDS AIDR-3D FBPQDS AIDR-3D 32 1548 2014. vol.61 no.746
CT Arts and Sciences 1Q&A. 10 94-100,, 20. 2 CT. 4 36-57,, 2009. 3MDCT X. 10 53-56, INNERVISION, 2010. 4 Aquilion ONE CT. 4 12-13, INNERVISION, 2010. 5 CT. 68 12 :1624-1630,, 2012. 6 CT. 10 14-27,, 2012. 7. 68 4 : 404-412,, 2012. 8 CT. 10 64-65, INNERVISION, 2010. 9 S.Richard et al. Towards task-based assessment of CT performance System and object MTF across different reconstruction algorithms. vol39, 7 4115-4122, Medical Physics, 2012. 10 CTNoise Power Spectrum. 68 12 1637-1643,, 2012. 11 CT. 4 120-137,, 2009. 12. 9 90-95,, 2008. 13 CT. 25 29-34,, 2008. 14. 27 February42-47,, 20. 15. 2 51-59,, 20. 16. 9 142-157,, 2008. 17. 5 31-44,, 2006. 18 X CT 4. 7 20-25,, 2013. 19 CT. 68 6 767-774,, 2012. 20. 9 56-80,, 2008. 33 1549