Radial reflection diffraction tomography

Abstract

A wave‐based tomographic imaging algorithm based upon a single, rotating, radially outward oriented transducer has been developed. At successive angular locations at a fixed radius, the transducer launches a primary field and collects the backscattered field in a ‘‘pitch/catch’’ operation. The hardware configuration, operating mode, and data collection method are identical to that of most medical intravascular ultrasound (IVUS) systems. The goal is to develop a wave‐based imaging algorithm using diffraction tomography techniques. Given the hardware configuration and the imaging method, this system is referred to as ‘‘radial reflection diffraction tomography.’’ Two hardware configurations are considered: a multimonostatic mode using a single transducer as described above, and a multistatic mode consisting of a single transmitter and an aperture formed by multiple receivers. The probe is mounted at the end of a catheter or snaking tube inserted into a part or medium with the goal of forming images of the plane perpendicular to the axis of rotation. An analytic expression for the multimonostatic inverse is derived but ultimately a Hilbert space inverse wave algorithm is used to construct images using both operating modes. Applications include improved IVUS imaging, bore hole tomography, and nondestructive evaluation (NDE) of parts with existing access holes.