Photoacoustic microscopy(PAM)operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues.Despite its potential,the effectiveness of lipid-bas...Photoacoustic microscopy(PAM)operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues.Despite its potential,the effectiveness of lipid-based PAM has been limited by the performance of existing nanosecond laser sources at this wavelength.In this work,we introduce a 1725-nm hybrid optical parametric oscillator emitter(HOPE)characterized by a narrow bandwidth of 1.4 nm,an optical signal-to-noise ratio(OSNR)of approximately 34 dB,and a high spectral energy density of up to 480 n J/nm.This advanced laser source significantly enhances the sensitivity of photoacoustic imaging,allowing for the detailed visualization of intrahepatic lipid distributions with an impressive maximal contrast ratio of 23.6:1.Additionally,through segmentation-based analysis of PAM images,we were able to determine steatosis levels that align with clinical assessments,thereby demonstrating the potential of our system for high-contrast,label-free lipid quantification.Our findings suggest that the proposed 1725-nm HOPE source could be a powerful tool for biomedical research and clinical diagnostics,offering a substantial improvement over current technologies in the accurate and non-invasive assessment of lipid accumulation in tissues.展开更多
基金Research Grants Council of the Hong Kong Special Administrative Region of China(HKU 17212824,HKU 17210522,HKU C7074-21G,HKU R7003-21,HKU 17205321)Innovation and Technology Commission of the Hong Kong SAR Government(MHP/073/20,MHP/057/21,Health@Inno HK program)Shenzhen Science Technology and Innovation Commission(SGDX20220530111403022)。
文摘Photoacoustic microscopy(PAM)operating within the 1.7-μm absorption window holds great promise for the quantitative imaging of lipids in various biological tissues.Despite its potential,the effectiveness of lipid-based PAM has been limited by the performance of existing nanosecond laser sources at this wavelength.In this work,we introduce a 1725-nm hybrid optical parametric oscillator emitter(HOPE)characterized by a narrow bandwidth of 1.4 nm,an optical signal-to-noise ratio(OSNR)of approximately 34 dB,and a high spectral energy density of up to 480 n J/nm.This advanced laser source significantly enhances the sensitivity of photoacoustic imaging,allowing for the detailed visualization of intrahepatic lipid distributions with an impressive maximal contrast ratio of 23.6:1.Additionally,through segmentation-based analysis of PAM images,we were able to determine steatosis levels that align with clinical assessments,thereby demonstrating the potential of our system for high-contrast,label-free lipid quantification.Our findings suggest that the proposed 1725-nm HOPE source could be a powerful tool for biomedical research and clinical diagnostics,offering a substantial improvement over current technologies in the accurate and non-invasive assessment of lipid accumulation in tissues.
