Li Zhiwei, Meng Zhouqi, Tian Feng, Ye Zuyang, Zhou Xuanfang, Zhong Xingjian, Chen Qian, Yang Mo, Liu Zhuang, Yin Yadong
Department of Chemistry, University of California, Riverside, California 92521, United States.
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
Nano Lett. 2022 Jul 13;22(13):5158-5166. doi: 10.1021/acs.nanolett.2c00854. Epub 2022 Jun 28.
Photoacoustic (PA) imaging uses photon-phonon conversion for high-resolution tomography of biological tissues and functions. Exogenous contrast agents are often added to improve the image quality, but the interference from endogenous molecules diminishes the imaging sensitivity and specificity. We report a background-free PA imaging technique based on the active modulation of PA signals via magnetic alignment of FeO@Au hybrid nanorods. Switching the field direction creates enhanced and deactivated PA imaging modalities, enabling a simple pixel subtraction to effectively minimize background noises. Under an alternating magnetic field, the nanorods exhibit PA signals of coherently periodic changes that can be converted into a sharp peak in a frequency domain via the fast Fourier transform. Automatic pixel-wise screening of nanorod signals performed using a computational algorithm across a time-sequence set of PA images regenerates a background-free PA image with significantly improved contrast, specificity, and fidelity.
光声（PA）成像利用光子 - 声子转换对生物组织和功能进行高分辨率断层扫描。通常会添加外源性造影剂来提高图像质量，但内源性分子的干扰会降低成像的灵敏度和特异性。我们报告了一种基于通过FeO@Au杂化纳米棒的磁取向对PA信号进行主动调制的无背景PA成像技术。切换磁场方向可创建增强和失活的PA成像模式，通过简单的像素减法可有效降低背景噪声。在交变磁场下，纳米棒呈现出相干周期性变化的PA信号，通过快速傅里叶变换可将其转换为频域中的尖锐峰值。使用计算算法对PA图像的时间序列集进行纳米棒信号的自动逐像素筛选，可生成对比度、特异性和保真度显著提高的无背景PA图像。
