TY - JOUR
T1 - Ultrasound-modulated optical microscopy
AU - Kothapalli, Sri Rajasekhar
AU - Wang, Lihong V.
N1 - Funding Information:
We thank Dr. S. Sakadzic for fruitful scientific and technical discussions and Dr. K. Maslov for preparing acoustic lenses for all four transducers used in our experiments. This research was supported by the National Institutes of Health through Grant Nos. R33 CA094267 and R01 CA106728.
PY - 2008
Y1 - 2008
N2 - We demonstrate that microscopic imaging is feasible in ultrasound-modulated optical tomography (UOT) of soft biological tissues, using a high-frequency focused ultrasound transducer with a 75-MHz central frequency. Our experiments in tissue mimicking phantoms show that at an imaging depth of about 2 mm, an axial resolution better than 30 μm can be achieved, whereas the lateral resolution is 38 μm. A long-cavity scanning confocal Fabry-Perot interferometer (CFPI) is used for real-time detection of multiply scattered light modulated by high-frequency ultrasound pulses propagating in an optically scattering medium. We also compare the performances of various high-frequency focused ultrasound transducers with central frequencies of 15 MHz, 30 MHz, 50 MHz, and 75 MHz. The comparison is based on two-dimensional (2-D) images of optically absorbing objects positioned at a few millimeters depth below the surface of both optically scattering phantoms and soft biological tissue samples. Our experimental results show that modulation depth and image contrast decrease with an increase in ultrasound frequency. In addition, we use analytical calculations to show that modulation depth decreases with increasing ultrasound frequency.
AB - We demonstrate that microscopic imaging is feasible in ultrasound-modulated optical tomography (UOT) of soft biological tissues, using a high-frequency focused ultrasound transducer with a 75-MHz central frequency. Our experiments in tissue mimicking phantoms show that at an imaging depth of about 2 mm, an axial resolution better than 30 μm can be achieved, whereas the lateral resolution is 38 μm. A long-cavity scanning confocal Fabry-Perot interferometer (CFPI) is used for real-time detection of multiply scattered light modulated by high-frequency ultrasound pulses propagating in an optically scattering medium. We also compare the performances of various high-frequency focused ultrasound transducers with central frequencies of 15 MHz, 30 MHz, 50 MHz, and 75 MHz. The comparison is based on two-dimensional (2-D) images of optically absorbing objects positioned at a few millimeters depth below the surface of both optically scattering phantoms and soft biological tissue samples. Our experimental results show that modulation depth and image contrast decrease with an increase in ultrasound frequency. In addition, we use analytical calculations to show that modulation depth decreases with increasing ultrasound frequency.
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U2 - 10.1117/1.2983671
DO - 10.1117/1.2983671
M3 - Article
C2 - 19021426
AN - SCOPUS:60849108664
SN - 1083-3668
VL - 13
JO - Journal of Biomedical Optics
JF - Journal of Biomedical Optics
IS - 5
M1 - 054046
ER -