光声成像的未来

1 光学成像的动机及其面临的挑战 目前已经有很多不同的医学成像技术。第一个技术是X射线成像,它是最早的医学成像。伦琴在1895年发现了X射线,从而诞生了医学成像这个新的领域。第二个技术是20世纪70年代发明的X射线CT,也就是计算层析成像。之后是超声成像,它历史悠久,在二战期间就已经开始发展,但没有用于医学,它的前身被称为“声纳”。较新的技术是核磁共振,它发明于20世纪70年代。相比其他成像方法,MRI（核磁共振成像）能进行功能成像,比结构成像进了一大步。     

High-resolution photoacoustic microscope for rat brain imaging in vivo

<正>A reflection-mode photoacoustic microscope(PAM) for rat brain imaging in vivo is constructed.A pulsed laser is used as an excitation source,and a focused ultrasound transducer is adopted to collect the photoacoustic signal.Raster scanning is applied to acquire three-dimensional(3D) data.The obtained measurements of the lateral and axial resolutions of the microscope are 45 and 15μm,respectively.The imaging depth in the chicken breast tissue is 3.1 mm at a signal-to-noise ratio(SNR) of 20 dB without any signal averaging.The imaging speed is 30 A-line/s.Experimental results in vivo demonstrate the capability of 3D imaging of the brain vessels of the rat after removing the skull.