University of Washington, Department of Bioengineering, 3720 15th Avenue NE, Seattle, Washington 98195, USA.
J Biomed Opt. 2012 Jun;17(6):061224. doi: 10.1117/1.JBO.17.6.061224.
Contrast-enhanced photoacoustic (PA) imaging has been proposed to identify circulating metastatic cancer cells magnetically trapped in the vasculature. However, its sensitivity is limited by the presence of a strong blood-background signal. This technique can be further improved by the significant suppression of blood background. In the phantom study presented here, significant background suppression is demonstrated with magnetomotive photoacoustic imaging. Magnetic particles with a mean diameter of 10 μm were integrated (concentration of 0.05 mg/ml) into an ink-water solution with an optical absorption coefficient of 5 cm(-1) to mimic cells targeted with magnetic nanoparticles and magnetically trapped in the human vasculature. Two mechanically moveable permanent magnets were used to accumulate microparticles in the investigated solution and manipulate them within a thin, 1.6-mm-diameter Teflon tube mimicking a blood vessel. Our results clearly indicate that the undesirable background can be effectively suppressed using the difference of PA images corresponding to different locations of accumulated particles.
对比增强光声（PA）成像是一种用于识别在血管中被磁捕获的循环转移性癌细胞的方法。然而，其灵敏度受到强烈的血液背景信号的限制。通过显著抑制血液背景，可以进一步提高该技术的灵敏度。在本研究中，利用磁驱动光声成像，显著抑制了血液背景。将平均直径为 10μm 的磁性颗粒（浓度为 0.05mg/ml）整合到具有 5cm-1 光吸收系数的墨水-水溶液中，以模拟与磁性纳米颗粒结合并在人血管中被磁捕获的细胞。两个可机械移动的永磁体用于在研究溶液中聚集微粒子，并在模拟血管的 1.6mm 直径特氟隆管内对其进行操纵。我们的结果清楚地表明，通过对应于聚集粒子不同位置的 PA 图像之间的差异，可以有效地抑制不需要的背景。
