Yun He, Yun He, Junhui Shi, K. Maslov, Lihong V. Wang
{"title":"用1 mhz a线速率的拉曼激光观察小鼠脑的双波长高速功能光声显微镜(会议报告)","authors":"Yun He, Yun He, Junhui Shi, K. Maslov, Lihong V. Wang","doi":"10.1117/12.2510658","DOIUrl":null,"url":null,"abstract":"Label-free functional photoacoustic microscopy (fPAM) has become a popular technology in small-animal hemodynamic studies. Here we report a stimulated-Raman-scattering-based (SRS) dual-wavelength high-speed fPAM that has achieved volumetric imaging at a 1 MHz A-line rate with capillary-level resolution. Potassium gadolinium tungstate (KGd(WO4)2) crystal is used as a Raman shifter to convert the pump 532 nm picosecond-pulsed laser to the first order Stokes line at 558 nm through the SRS effect with ~40% efficiency and a much narrower line width compared with previous fiber-based SRS PAMs. We also developed a water-immersible micro-electro-mechanical system scanner for scanning a ~4-mm range at a 500 Hz B-scan rate, while maintaining the optic-acoustic confocal alignment. This scanner is assembled entirely from commercially available components, facilitating replication. The detection sensitivity of our fPAM is also improved by employing a high numerical aperture polyvinylidene fluoride ultrasonic transducer, whose acoustic impedance matches better with tissue coupling medium than traditional ceramic transducers. The high sensitivity combined with ~2.4 µm resolution enabled our fPAM to image single red blood cells with a signal-to-noise ratio of ~27 dB. Compared with our previous laser-pulse-width based fPAM, we achieved simultaneous imaging of hemoglobin concentration and oxygenation with a 5-fold increase in imaging speed. Moreover, our system works in a convenient free-space manner compared to previous SRS-based PAMs. We applied it to imaging vasculature and blood oxygen saturation on mouse brains in both resting and stimulated states.","PeriodicalId":206495,"journal":{"name":"Photons Plus Ultrasound: Imaging and Sensing 2019","volume":"24 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Dual-wavelength high-speed functional photoacoustic microscopy of mouse brain with a Raman laser at 1-MHz A-line rate (Conference Presentation)\",\"authors\":\"Yun He, Yun He, Junhui Shi, K. Maslov, Lihong V. Wang\",\"doi\":\"10.1117/12.2510658\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Label-free functional photoacoustic microscopy (fPAM) has become a popular technology in small-animal hemodynamic studies. Here we report a stimulated-Raman-scattering-based (SRS) dual-wavelength high-speed fPAM that has achieved volumetric imaging at a 1 MHz A-line rate with capillary-level resolution. Potassium gadolinium tungstate (KGd(WO4)2) crystal is used as a Raman shifter to convert the pump 532 nm picosecond-pulsed laser to the first order Stokes line at 558 nm through the SRS effect with ~40% efficiency and a much narrower line width compared with previous fiber-based SRS PAMs. We also developed a water-immersible micro-electro-mechanical system scanner for scanning a ~4-mm range at a 500 Hz B-scan rate, while maintaining the optic-acoustic confocal alignment. This scanner is assembled entirely from commercially available components, facilitating replication. The detection sensitivity of our fPAM is also improved by employing a high numerical aperture polyvinylidene fluoride ultrasonic transducer, whose acoustic impedance matches better with tissue coupling medium than traditional ceramic transducers. The high sensitivity combined with ~2.4 µm resolution enabled our fPAM to image single red blood cells with a signal-to-noise ratio of ~27 dB. Compared with our previous laser-pulse-width based fPAM, we achieved simultaneous imaging of hemoglobin concentration and oxygenation with a 5-fold increase in imaging speed. Moreover, our system works in a convenient free-space manner compared to previous SRS-based PAMs. We applied it to imaging vasculature and blood oxygen saturation on mouse brains in both resting and stimulated states.\",\"PeriodicalId\":206495,\"journal\":{\"name\":\"Photons Plus Ultrasound: Imaging and Sensing 2019\",\"volume\":\"24 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-03-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Photons Plus Ultrasound: Imaging and Sensing 2019\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1117/12.2510658\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Photons Plus Ultrasound: Imaging and Sensing 2019","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1117/12.2510658","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Dual-wavelength high-speed functional photoacoustic microscopy of mouse brain with a Raman laser at 1-MHz A-line rate (Conference Presentation)
Label-free functional photoacoustic microscopy (fPAM) has become a popular technology in small-animal hemodynamic studies. Here we report a stimulated-Raman-scattering-based (SRS) dual-wavelength high-speed fPAM that has achieved volumetric imaging at a 1 MHz A-line rate with capillary-level resolution. Potassium gadolinium tungstate (KGd(WO4)2) crystal is used as a Raman shifter to convert the pump 532 nm picosecond-pulsed laser to the first order Stokes line at 558 nm through the SRS effect with ~40% efficiency and a much narrower line width compared with previous fiber-based SRS PAMs. We also developed a water-immersible micro-electro-mechanical system scanner for scanning a ~4-mm range at a 500 Hz B-scan rate, while maintaining the optic-acoustic confocal alignment. This scanner is assembled entirely from commercially available components, facilitating replication. The detection sensitivity of our fPAM is also improved by employing a high numerical aperture polyvinylidene fluoride ultrasonic transducer, whose acoustic impedance matches better with tissue coupling medium than traditional ceramic transducers. The high sensitivity combined with ~2.4 µm resolution enabled our fPAM to image single red blood cells with a signal-to-noise ratio of ~27 dB. Compared with our previous laser-pulse-width based fPAM, we achieved simultaneous imaging of hemoglobin concentration and oxygenation with a 5-fold increase in imaging speed. Moreover, our system works in a convenient free-space manner compared to previous SRS-based PAMs. We applied it to imaging vasculature and blood oxygen saturation on mouse brains in both resting and stimulated states.