The goal of this study is to develop and evaluate advanced annular-array transducer technology for rapid, high-definition imaging in significant medical-research applications. The study will assess high frequency ultrasound (HFU, = 20 MHz) annular arrays in two important applications: 1) imaging microstructure in small animals (e.g., mouse embryos); and 2) imaging posterior vitreous detachments (PVDs) associated with diabetic retinopathy, the leading cause of blindness in the US working-age population according to Prevent Blindness America. Current HFU instruments do not use linear arrays for such applications because of a variety of technical and cost reasons. Instead, current HFU instruments use mechanically scanned, single-element transducers, which provide fine-resolution images over a very limited depth of field (DOF). For small-animal applications, a shallow DOF causes most anatomical boundaries in the specimen to be poorly defined; therefore, accurate micro-structural and volumetric analyses are nearly impossible. For ophthalmic applications, a shallow DOF causes most ocular anatomy to be imaged with poor definition compared to the in-focus region; therefore, because only a small portion of the eye is in focus at a given time, detection and assessment of ocular conditions such as PVD are prone to inaccuracies and false-negative determinations. Annular-array transducers offer a promising approach to significantly extend DOF and to increase the depth range over which fine-lateral resolution is provided. This proposal seeks to continue the HFU annular-array studies initiated under grant EY014371 that demonstrated the improved imaging capability of synthetically-focused annular arrays using in vivo rabbit eyes, in vivo mouse embryos, and human eye-bank eyes. The proposed project will extend those previous studies by developing and validating a real-time HFU, annular-array-based, rapid-imaging system capable of 1) dynamic-receive display imaging at a rate of > 10 fps; 2) data acquisition in < 0.2 s for single-frame, synthetically-focused imaging; and 3) 3D data collection in < 20 s. The proposed system will be modular to facilitate upgrading system components and features. We will validate system performance using animal experiments and human-subject examinations. First, in vivo animal experiments will be conducted with rabbit eyes to evaluate a 40-MHz annular array for anterior-segment imaging and a 20-MHz annular array for posterior segment and full-globe imaging. We also will utilize the 40-MHz annular array to perform in vivo 3D imaging and volumetric segmentation studies with mouse embryos. Second, we will test the hypothesis that 20-MHz annular arrays improve detection of PVD. Validation of this hypothesis will significantly improve our ability to assess disease status in diabetic retinopathy. ? ? ?
| Chitnis, Parag V; Aristizábal, Orlando; Filoux, Erwan et al. (2016) Coherence-Weighted Synthetic Focusing Applied to Photoacoustic Imaging Using a High-Frequency Annular-Array Transducer. Ultrason Imaging 38:32-43 |
| Aristizábal, Orlando; Mamou, Jonathan; Ketterling, Jeffrey A et al. (2013) High-throughput, high-frequency 3-D ultrasound for in utero analysis of embryonic mouse brain development. Ultrasound Med Biol 39:2321-32 |
| Alibakhshi, Mohammad A; Kracht, Jonathan M; Cleveland, Robin O et al. (2013) Single-shot measurements of the acoustic field of an electrohydraulic lithotripter using a hydrophone array. J Acoust Soc Am 133:3176-85 |
| Filoux, Erwan; Sampathkumar, Ashwin; Chitnis, Parag V et al. (2013) High-frequency annular array with coaxial illumination for dual-modality ultrasonic and photoacoustic imaging. Rev Sci Instrum 84:053705 |
| Lethiecq, Marc; Lou-Moeller, Rasmus; Ketterling, Jeffrey et al. (2012) Non-planar pad-printed thick-film focused high-frequency ultrasonic transducers for imaging and therapeutic applications. IEEE Trans Ultrason Ferroelectr Freq Control 59:1976-82 |
| Ketterling, Jeffrey A; Filoux, Erwan (2012) Synthetic-focusing strategies for real-time annular-array imaging. IEEE Trans Ultrason Ferroelectr Freq Control 59:1830-9 |
| Silverman, Ronald H; Ketterling, Jeffrey A; Mamou, Jonathan et al. (2012) Pulse-encoded ultrasound imaging of the vitreous with an annular array. Ophthalmic Surg Lasers Imaging 43:82-6 |
| Filoux, Erwan; Mamou, Jonathan; Moran, Carmel M et al. (2012) Correspondence - Characterization of the effective performance of a high-frequency annular-array-based imaging system using anechoic-pipe phantoms. IEEE Trans Ultrason Ferroelectr Freq Control 59:2825-30 |
| Filoux, Erwan; Mamou, Jonathan; Aristizabal, Orlando et al. (2011) Characterization of the spatial resolution of different high-frequency imaging systems using a novel anechoic-sphere phantom. IEEE Trans Ultrason Ferroelectr Freq Control 58:994-1005 |
| Mamou, Jonathan; Aristizábal, Orlando; Silverman, Ronald H et al. (2009) High-frequency chirp ultrasound imaging with an annular array for ophthalmologic and small-animal imaging. Ultrasound Med Biol 35:1198-208 |
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