University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States.
University of Washington, Department of Bioengineering, 616 NE Northlake Place, Seattle, WA 98105, United States ; University of Washington, Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, 1013 NE 40th Street, Seattle, WA 98105-6698, United States.
Photoacoustics. 2015 Jan 28;3(1):11-9. doi: 10.1016/j.pacs.2015.01.001. eCollection 2015 Mar.
Photoacoustic (PA) imaging using exogenous agents can be limited by degraded specificity due to strong background signals. This paper introduces a technique called sono-photoacoustics (SPA) applied to perfluorohexane nanodroplets coated with gold nanospheres. Pulsed laser and ultrasound (US) excitations are applied simultaneously to the contrast agent to induce a phase-transition ultimately creating a transient microbubble. The US field present during the phase transition combined with the large thermal expansion of the bubble leads to 20-30 dB signal enhancement. Aqueous solutions and phantoms with very low concentrations of this agent were probed using pulsed laser radiation at diagnostic exposures and a conventional US array used both for excitation and imaging. Contrast specificity of the agent was demonstrated with a coherent differential scheme to suppress US and linear PA background signals. SPA shows great potential for molecular imaging with ultrasensitive detection of targeted gold coated nanoemulsions and cavitation-assisted theranostic approaches.
基于外源试剂的光声（PA）成像是有限的，因为强烈的背景信号会降低其特异性。本文介绍了一种名为声-光声（SPA）的技术，该技术应用于涂有金纳米球的全氟己烷纳米液滴。脉冲激光和超声（US）同时应用于对比试剂以诱导相变，最终产生瞬态微泡。相变过程中的 US 场与气泡的大幅热膨胀相结合，导致信号增强 20-30dB。使用诊断辐射的脉冲激光辐射探测极低浓度该试剂的水溶液和体模，并使用传统的 US 阵列同时进行激发和成像。该试剂的对比特异性通过相干差分方案得到了证明，该方案可抑制 US 和线性 PA 背景信号。SPA 具有很大的分子成像潜力，可用于超灵敏检测靶向金涂覆纳米乳液和空化辅助治疗方法。
