title: Lock-in camera based heterodyne holography for ultrasound-modulated optical tomography inside dynamic scattering media.
abstract: Ultrasound-modulated optical tomography (UOT) images optical contrast deep inside scattering media. Heterodyne holography based UOT is a promising technique that uses a camera for parallel speckle detection. In previous works, the speed of data acquisition was limited by the low frame rates of conventional cameras. In addition, when the signal-to-background ratio was low, these cameras wasted most of their bits representing an informationless background, resulting in extremely low efficiencies in the use of bits. Here, using a lock-in camera, we increase the bit efficiency and reduce the data transfer load by digitizing only the signal after rejecting the background. Moreover, compared with the conventional four-frame based amplitude measurement method, our single-frame method is more immune to speckle decorrelation. Using lock-in camera based UOT with an integration time of 286μs, we imaged an absorptive object buried inside a dynamic scattering medium exhibiting a speckle correlation time ([Formula: see text]) as short as 26μs. Since our method can tolerate speckle decorrelation faster than that found in living biological tissue ([Formula: see text] ∼ 100-1000μs), it is promising forin vivodeep tissue non-invasive imaging.
authors: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, USA.
authors: Yan
authors: Y
authors: Liu
authors: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, USA.
authors: Yuecheng
authors: 0000-0003-1990-8142
authors: Y
authors: Shen
authors: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, USA.
authors: Cheng
authors: C
authors: Ma
authors: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, USA.
authors: Junhui
authors: J
authors: Shi
authors: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis , St. Louis, Missouri 63130, USA.
authors: Lihong V
authors: LV
authors: Wang