Improvement of frame-rate is very important for high quality ultrasound imaging of fast-moving structures.It is also one of the key technologies of Three-Dimension(3-D) real-time medical imaging.In this paper,we have ...Improvement of frame-rate is very important for high quality ultrasound imaging of fast-moving structures.It is also one of the key technologies of Three-Dimension(3-D) real-time medical imaging.In this paper,we have demonstrated a beamforming method which gives imaging frame-rate increment without sacrificing the quality of medical images.By using wider and fewer transmit beams in combination with four narrower parallel receive beams,potentially increasing the imaging frame-rate by a factor four.Through employing full transmit aperture,controlling the mainlobe width,and suppressing sidelobes of angular responses,the inherent gain loss of normal parallel beamfomer can be compensated in the maximal degree.The noise and interference signals also can be suppressed effectively.Finally,we show comparable lateral resolution and contrast of ultrasound images to normal single widow weighting beamformer on simulated phantoms of point targets,cyst and fetus of 12th week.As the computational cost is linear with the number of array elements and the same with Delay And Sum(DAS) beamformers,this method has great ad-vantages of possibility for high frame-rate real-time applications.展开更多
X-ray excited luminescence(XEL)of scintillators is significant for imaging applications in the fields of medical detection,information retrieval,and scientific research.In this case,lanthanide-doped rare-earth nanopho...X-ray excited luminescence(XEL)of scintillators is significant for imaging applications in the fields of medical detection,information retrieval,and scientific research.In this case,lanthanide-doped rare-earth nanophosphors show potential as next-generation scintillators owing to their facile synthesis,high chemical stability and photostability,and adjustable XEL emission.In this study,a new type of XEL-enhanced NaLuF_(4)-based nanophosphor was synthesized by doping Tb^(3+)to sensitize the emission of Eu^(3+),facilitating the application of the as-prepared nanoscintillators for X-ray imaging on opaque samples and biological specimens.NaLuF_(4):Gd/Tb/Eu with 5%Tb-doping showed the highest XEL intensity owing to the energy transfer process between Tb^(3+)and Eu^(3+).The NaLuF_(4):Gd/Tb/Eu(10/5/15 mol%)nanoparticles exhibited an excellent scintillation performance with a high light yield of 15313 photons MeV-1 and low detection limit of 84.1 nGyair s^(-1).The X-ray imaging test using the NaLuF_(4):Gd/Tb/Eu(10/5/15 mol%)-based scintillation film exhibited a high spatial resolution of 8.7 lp mm^(-1).Furthermore,the NaLuF_(4):Gd/Tb/Eu(10/5/15 mol%)-based scintillation film was applied in X-ray imaging with high contrast for a spring sealed in a capsule and a crab.展开更多
文摘Improvement of frame-rate is very important for high quality ultrasound imaging of fast-moving structures.It is also one of the key technologies of Three-Dimension(3-D) real-time medical imaging.In this paper,we have demonstrated a beamforming method which gives imaging frame-rate increment without sacrificing the quality of medical images.By using wider and fewer transmit beams in combination with four narrower parallel receive beams,potentially increasing the imaging frame-rate by a factor four.Through employing full transmit aperture,controlling the mainlobe width,and suppressing sidelobes of angular responses,the inherent gain loss of normal parallel beamfomer can be compensated in the maximal degree.The noise and interference signals also can be suppressed effectively.Finally,we show comparable lateral resolution and contrast of ultrasound images to normal single widow weighting beamformer on simulated phantoms of point targets,cyst and fetus of 12th week.As the computational cost is linear with the number of array elements and the same with Delay And Sum(DAS) beamformers,this method has great ad-vantages of possibility for high frame-rate real-time applications.
基金financial support from National Funds for Distinguished Young Scientists(61825503)the National Key R&D Program of China(grant no.2020YFA0709900)+1 种基金the National Natural Science Foundation of China(22161160318 and 62275129)the Project of State Key Laboratory of Organic Electronics and Information Displays,and Nanjing University of Posts&Telecommunications(NY219059,NY220022).
文摘X-ray excited luminescence(XEL)of scintillators is significant for imaging applications in the fields of medical detection,information retrieval,and scientific research.In this case,lanthanide-doped rare-earth nanophosphors show potential as next-generation scintillators owing to their facile synthesis,high chemical stability and photostability,and adjustable XEL emission.In this study,a new type of XEL-enhanced NaLuF_(4)-based nanophosphor was synthesized by doping Tb^(3+)to sensitize the emission of Eu^(3+),facilitating the application of the as-prepared nanoscintillators for X-ray imaging on opaque samples and biological specimens.NaLuF_(4):Gd/Tb/Eu with 5%Tb-doping showed the highest XEL intensity owing to the energy transfer process between Tb^(3+)and Eu^(3+).The NaLuF_(4):Gd/Tb/Eu(10/5/15 mol%)nanoparticles exhibited an excellent scintillation performance with a high light yield of 15313 photons MeV-1 and low detection limit of 84.1 nGyair s^(-1).The X-ray imaging test using the NaLuF_(4):Gd/Tb/Eu(10/5/15 mol%)-based scintillation film exhibited a high spatial resolution of 8.7 lp mm^(-1).Furthermore,the NaLuF_(4):Gd/Tb/Eu(10/5/15 mol%)-based scintillation film was applied in X-ray imaging with high contrast for a spring sealed in a capsule and a crab.
