Lipid imaging by conventional photoacoustic microscopy subjects to direct contact sensing with relatively low detection bandwidth and sensitivity,which induces superficial imaging depth and low signalto-noise ratio(S...Lipid imaging by conventional photoacoustic microscopy subjects to direct contact sensing with relatively low detection bandwidth and sensitivity,which induces superficial imaging depth and low signalto-noise ratio(SNR)in practical imaging scenarios.Herein,we present a photoacoustic remote sensing microscopy for lipid distribution mapping in bio-tissue,featuring noncontact implementation,broad detection bandwidth,deep penetration depth,and high SNR.A tailored high-energy pulsed laser source with a spectrum centered at 1750 nm is used as the excitation beam,while a cofocused 1550 nm continuous-wave beam is used as the probe signal.The pump wavelength is selected to overlap the first overtone of the C-H bond in response to the intensive absorption of lipid molecules,which introduces a much-enhanced SNR(55 dB)onto photoacoustic remote sensing(PARS)signals.Meanwhile,the optical sensing scheme of the photoacoustic signals provides broadband detection compared to the acoustic transducer and refrains the bio-samples from direct contact operations by eliminating the ultrasonic coupling medium.Taking merits of the high detection sensitivity,deep penetration depth,broadband detection,and high resolution of the PARS system,high-quality tissue scale lipid imaging is demonstrated in a model organism and brain slice.展开更多
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region of China(Grant Nos.HKU 17210522,HKU C7074-21G,HKU 17205321,HKU 17200219,HKU 17209018,and CityU T42-103/16-N)the Health@InnoHK Program of the Innovation and Technology Commission of the Hong Kong SAR Government.
文摘Lipid imaging by conventional photoacoustic microscopy subjects to direct contact sensing with relatively low detection bandwidth and sensitivity,which induces superficial imaging depth and low signalto-noise ratio(SNR)in practical imaging scenarios.Herein,we present a photoacoustic remote sensing microscopy for lipid distribution mapping in bio-tissue,featuring noncontact implementation,broad detection bandwidth,deep penetration depth,and high SNR.A tailored high-energy pulsed laser source with a spectrum centered at 1750 nm is used as the excitation beam,while a cofocused 1550 nm continuous-wave beam is used as the probe signal.The pump wavelength is selected to overlap the first overtone of the C-H bond in response to the intensive absorption of lipid molecules,which introduces a much-enhanced SNR(55 dB)onto photoacoustic remote sensing(PARS)signals.Meanwhile,the optical sensing scheme of the photoacoustic signals provides broadband detection compared to the acoustic transducer and refrains the bio-samples from direct contact operations by eliminating the ultrasonic coupling medium.Taking merits of the high detection sensitivity,deep penetration depth,broadband detection,and high resolution of the PARS system,high-quality tissue scale lipid imaging is demonstrated in a model organism and brain slice.
