In molecular and cellular photoacoustic imaging with exogenous contrast agents, image contrast is plagued by background resulting from endogenous absorbers in tissue. By using optically modulatable nanoparticles, we develop ultra-sensitive photoacoustic imaging by rejecting endogenous background signals and drastically improving signal contrast through time-delayed pump-probe pulsed laser illumination. Gated by prior pump excitation, modulatable photoacoustic (mPA) signals are recovered from unmodulatable background through simple, real-time image processing to yield background-free photoacoustic signal recovery within tissue mimicking phantoms and from ex-vivo tissues. Inherently multimodal, the fluorescence and mPA sensitivity improvements demonstrate the promise of Synchronously Amplified Photoacoustic Image Recovery (SAPhIRe) for PA imaging in diagnosis and therapy.

在使用外源性造影剂的分子和细胞光声成像中，图像对比度受到组织中内源性吸收剂产生的背景的困扰。通过使用可光学调节的纳米粒子，我们通过拒绝内源性背景信号并通过延时泵浦脉冲脉冲激光照明大大改善了信号对比度，从而开发了超灵敏的光声成像。通过先前的泵浦激励进行选通，可调制的光声（mPA）信号通过简单的实时图像处理从不可调制的背景中恢复，从而在模拟体模的组织和离体组织中实现了无背景的光声信号恢复。本质上是多峰的，