Research On Photoacoustic Microscopy Respiratory-gating Technique For Living Mice

Photoacoustic microscopy imaging is a rapidly new developing biomedical imaging technology in recent years.It combines the high contrast of optical imaging with he high penetration depth of ultrasound imaging,it can performs structural,functional and molecular imaging of animals and provides excellent optical absorption contrast in deeper levels.However,when acquiring images of chest or abdomen of living animals with photoacoustic microscopy imaging,because photoacoustic microscopy requires high image resolution,motion artifact and deterioration of resolution are caused by the respiratory motion.Therefore,respiratory-gated photoacoustic microscopy imaging is required.The main content of this paper is to design and implement the prospective respiratory-gated technology based on optical resolution photoacoustic microscopy imaging system.Using the triangulation method of the laser displacement sensor,the respiratory signal of the animals was obtained without contact.Using a respiratory signal acquisition interface based on the Lab VIEW to obtain appropriate respiratory signal waveforms,and programed a set of software which based on visual studio 2010 to control the gated system,avoiding the effect of respiratory to the biological image.The scanning mode and the scanning timing were also designed and evaluatd,the process of triggering the system by a specific phase of the respiratory signal and performing a segmented scan on the biological sample is described.After the technology was implemented,the black tape was scanned two-dimensionall and the splicing artefact problem caused by acceleration and deceleration in the segmented scanning process of the translation stage was solved,it ensures a signal-to-noise ratio of the imageA series of experiments were taken to verify the feasibility of this technology: First,the tungsten wire attached to the abdomen of the mouse was imaging and it can verify the system has a clear debounce effect.Finally,imaging the abdominal blood vessels of Balb/C mice and the livers of C57 mice,the ability of the technology in vivo imaging was verified.