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Tomographie ultrasonore dédiée à l'imagerie du sein - Validation expérimentale du projet ANAÏS

Abstract : Ultrasound computed tomography has considerable otential as a means of breast cancer detection since it reduces the operator-dependency observed in echography. A half-ring transducer array was designed based on the breast anatomy, to obtain refl ectivity images of the ductolobular structures using tomographic reconstruction procedures. The 3-MHz transducer array comprises 1024 elements set, in a 190-degree circular arc with a radius of 100 mm. The front-end electronics incorporate 32 independent parallel transmit/receive channels and a 32-to-1024 multiplexer unit. The transmit and receive circuitries have a variable sampling frequency of up to 80 MHz and a 12-bit precision. Arbitrary waveforms are synthesized to improve the signal-to-noise ratio. The set-up was calibrated with academic objects and a needle hydrophone to develop the data correction tools and specify the properties of the system ; results are compared with the formalism of inverse problem (elliptical back-projection summation algorithm). The backscattering field was recorded using a restricted aperture, and tomographic acquisitions were performed with a pair of 0.08 mm diameter steel threads, a low contrast 2-D breast phantom, and a breast-shaped phantom containing inclusions. The pulse compression is used and the contribution of this technique to ultrasound computed tomography is evaluated with respect to the use of a standard broadband pulse. Prospects for development of inspection methods and also adaptations of the electroacoustic set-up dedicated to the anatomical tomographic imaging are proposed relative to conducted studies during this thesis.
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https://tel.archives-ouvertes.fr/tel-00733152
Contributor : Julien Rouyer <>
Submitted on : Tuesday, September 18, 2012 - 9:56:35 AM
Last modification on : Thursday, January 23, 2020 - 6:22:03 PM
Long-term archiving on: : Wednesday, December 19, 2012 - 3:44:09 AM

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  • HAL Id : tel-00733152, version 1

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Julien Rouyer. Tomographie ultrasonore dédiée à l'imagerie du sein - Validation expérimentale du projet ANAÏS. Acoustique [physics.class-ph]. Université de Provence - Aix-Marseille I, 2012. Français. ⟨tel-00733152⟩

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