High contrast and resolution 3-D ultrasonography with a clinical linear transducer array scanned in a rotate-translate geometry

Théotim Lucas (1) , Isabelle Quidu (2) , Lori S Bridal (1) , Jerome Gateau (1)

1 LIB - Laboratoire d'Imagerie Biomédicale [Paris]
2 Lab-STICC_ENSTAB_CID_PRASYS

We propose a novel solution for volumetric ultrasound imaging using single-side access 3-D synthetic-aperture scanning of a clinical linear array. This solution is based on an advanced scanning geometry and a software-based ultrasound platform. The rotate-translate scanning scheme increases the elevation angular aperture by pivoting the array [-45° to 45°] around its array axis (axis along the row of its elements) and then, scans the imaged object for each pivoted angle by translating the array perpendicularly to the rotation axis. A theoretical basis is presented so that the angular and translational scan sampling periods can be best adjusted for any linear transducer array. We experimentally implemented scanning with a 5-MHz array. In vitro characterization was performed with phantoms designed to test resolution and contrast. Spatial resolution assessed based on the full-width half-maximum of images from isolated microspheres was increased by a factor 3 along the translational direction from a simple translation scan of the array. Moreover, the resolution is uniform over a cross-sectional area of 4.5 cm 2. Angular sampling periods were optimized and tapered to decrease the scan duration while maintaining image contrast (contrast at the center of a 5 mm cyst on the order of-26 dB for 4° angular period and a scan duration of 10 s for a 9cm 3 volume). We demonstrate that superior 3-D US imaging can be obtained with a clinical array using our scanning strategy. This technique offers a promising and flexible alternative to development of costly matrix arrays toward the development of sensitive volumetric ultrasonography.

Mots clés: volumetric imaging; ultrasonography; synthetic aperture; tomographic scan; linear array; spatial sampling

Domaines: Acoustique [physics.class-ph]; Imagerie

Théotim Lucas, Isabelle Quidu, Lori S Bridal, Jerome Gateau. High contrast and resolution 3-D ultrasonography with a clinical linear transducer array scanned in a rotate-translate geometry. 2020. ⟨hal-03011745v1⟩