超声相干平面波成像-Ghost_busting_IEEE_IUS_2015.pptx

Klikk for redigere tittelstil,Klikk for redigere tekststiler i malen,Andre niv,Tredje niv,Fjerde niv,Femte niv,Busting the ghost in coherent plane-wave imaging,Alfonso Rodriguez-Molares,Lasse Lvstakken,Bastien Denarie,and,Hans,Torp,Centre for Innovative,Ultrasound Solutions,Contents,Background,Contrast ratio in CPWC,Results,In-vitro data of the contrast,ratio in,CPWC,In-silico data,of the contrast ratio in CPWC,A picture of a ghost,Theory,What we know about ghost?,Understanding the ghost,Busting the ghost?,Results(again),Busting the ghost in CPWC images,Discussion,Background,Resolution,Contrast Ratio,Increases with the,number of plane-waves,Results,Experimental apparatus,Verasonics 256 Vantage scanner,L12-3v probe:192-element,9 MHz,0.2 mm pitch,STAI dataset:1.5 cycles,CPWC dataset:1.5 cycles,F,=,1.2,Boxcar,23.87,Results,-Anechoic cyst optimally focused,Optimally focused beams,Results,-Anechoic cyst CPWC,Montaldo et al.2009,Rodriguez-Molares et al.now,Results,-Anechoic cyst CPWC,Optimally focused beams,1 J.A.Jensen:,Field:A Program for Simulating Ultrasound Systems,Paper presented at the 10th Nordic-Baltic Conference on Biomedical Imaging Published in Medical&Biological Engineering&Computing,pp.351-353,Volume 34,Supplement 1,Part 1,1996.,2 J.A.Jensen and N.B.Svendsen:,Calculation of pressure fields from arbitrarily shaped,apodized,and excited ultrasound transducers,IEEE Trans.Ultrason.,Ferroelec.,Freq.Contr.,39,pp.262-267,1992.,Results,Simulated PSF optimally focused,Results,Simulated PSF CPWC,Point Spread Function Field II,Anechoic cyst-Experiment,Results,Experimental and Simulation,PSF tail,Edge waves,Range lobes,Results,The ghost,Theory,what we know about the ghost,related to the edges of the aperture as its influence can be reduced with a 25%tukey apodization,Point Spread Function Field II,Anechoic cyst-Experiment,Theory,understanding the ghost,Theory,understanding the ghost,Theory,understanding the ghost,Theory,understanding the ghost,Theory,understanding the ghost,Theory,busting the ghost,Theory,busting the ghost,angle,dependent transmit apodization(ADTA),Theory,busting the ghost,Results,Simulated,PSF,ADTA,Results,Anechoic cyst,ADTA,Results,-,Comparison,Point Spread Function Field II,Anechoic cyst-Experiment,Discussion,Advantages:,Higher contrast ratio than any other transmit apodization scheme,Faster convergence to the theoretical maximum CR,Ghost free images!,Drawbacks:,Discussion,Transmit apodization optimised for a specific point,Discussion,the catch,N=63,N=63,Discussion,the catch,Discussion,compromise between CR and coverage,Broad ADTA,Discussion,Advantages:,Higher contrast ratio than any other Transmit Apodization,Faster convergence to theoretical maximum,Ghost free!,Drawbacks:,Reduced coverage,Optimal CR in close-ups,Suboptimal CR in full frames,Or,optimal CR with multiple transmitions,full,frame,Needle Detection by Image Source Localization,Alfonso Rodriguez-Molares,Lasse Lvstakken,Ingvild Kinn Ekroll,and Hans Torp,Tha-a-a-anks!,Centre for Innovative,Ultrasound Solutions,