Photoacoustic imaging of a biological sample using in-phase-sum focus algorithm

摘要

Photoacoustic (PA) imaging is a new imaging modality, whic hconverts pressure signals received by an array of transducers to a regional distribution of electromagnetic absorption density. In this paper we present an experiment result of a photoacoustic imaging to depths of approx 3-mm for a fabricated absorber within a real tissue, using a 1064-nm pulse YAG laser. The time-resolved stress detection technique was used for PA signal detection and an in-phase-sum-focus algorithm was used for iamge reconstruction. To obtain excellent temporal resolution, a wideband PVDF membrane hydrophone and a fast-digitizing oscilloscope was used for time-resoved detection of PA signals. A computer controled translation stage on which the sample cell was fixed was used to a 2D scanning mode. Images of different depth profile was obtained with a lateral and depth resolution of approx 0.5mm.