A novel technique for measuring ultrasound backscatter from single micron-sized objects

摘要: The measurement of the ultrasound backscatter from individual micron-sized objects is required to gain an understanding behavior both weak (cells) and strong (contrast agents) scatterers for applications ranging tissue characterization molecular imaging. However, obtaining such a response remains challenge. For instance, presence air bubbles in suspension cells during measurements cell may lead incorrect interpretation backscattered signals. In addition, size shape single object that produces signal are critical input parameters theoretical models, yet hard be measured experimentally. this work, novel technique combining Xenoworks microinjection system (Sutter, Inc., Los Angeles, CA) with co-registered Olympus IX71 inverted microscope (Olympus America, Center Valley, PA) VEVO770 Ultrasound imaging device (VisualSonics, Toronto, ON) was developed which obtained under optical guidance. This provides accurate information about object. Two transducers central frequencies 25 55 MHz were used (for total spectrum 12–57 MHz). foci lens transducer aligned obtain ultrasonic images same region. interest attached micropipette (using negative pressure) then released positive pressure and/or tapping on micropipette) while it optically ultrasonically. order calibrate system, grab 20 µm polystyrene microsphere microspheres degassed water by applying −18.9 kPa. +35.0 During release, raw RF lines obtained. These power spectral plot compared analytical solutions. A very good agreement found (error 1%) between Faran model elastic sphere. Extension method prostate carcinoma (PC-3) showed 5%) when Anderson fluid sphere model. capable providing currently being deduce other different sizes contrast agents either isolation or cell. advantages along its future discussed.