Free of speckle ultrasonic imaging of soft tissue with account of second harmonic signal

Abstract

The Born approximation deconvolved inverse scattering imaging technique is an alternative to the conventional pulse-echo method. This novel technique deconvolves the incident pulse from the reflected pulse, and uses the resulting impulse response to produce an image of the acoustic impedance distribution. It is applicable mainly to structures that resemble a layered medium. The images captured by this method prove to have improved resolution and are free of speckle. With this method one can use ultrasound of lower frequencies than would be required by the pulse-echo method to achieve the same resolution. To provide further improvement of images the second harmonic signals can be employed. Here we describe the deconvolved inverse scattering imaging technique with account of the second harmonic signal. For this purpose the hybrid transducer by Krautkramer Branson Co., which consists of a cylindrical 5 MHz transducer wrapped in an annulus-shaped 2.5 MHz transducer, has been used. The phantom and soft tissue were imaged and in both cases the account of the second harmonic reflection data provides an improvement of the image quality.

Pre-surgical evaluation of ICA-stenosis using 3D power Doppler, 3D color coded Doppler sonography, 3D B-flow and contrast enhanced B-flow in correlation to CTA/MRA: First clinical results

“…They accord with reconstructions created in CTA and MRA as well as surgical result. In particular cases, irregular, anechoic stenosis and ulcerating plaques can be visualized more vividly using Cross Beam Technique and Speckle Reduction Imaging (SRI) [9][10][11][12]29].…”

“…Even initial arteriosclerosis lesions, plaques or intimaflaps can be visualized using Tissue Harmonic Imaging (THI) with Cross Beam Technique/ultrasound CT Technique and Speckle Reduction Imaging (SRI) [9][10][11][12]. Furthermore, these techniques provide a spatial resolution unrivaled by computed tomography/CT-angiography (CT/CTA) or magnetic resonance imaging/MR-angiography (MRI/MRA).…”

Validity of a modified Born approximation for a pulsed plane wave in acoustic scattering problems

“…where g(k) is the weight factor for spatial frequency k and the form of g(k) depends upon the shape of the incident pulse. A real pulse emitted by a medical ultrasound transducer can be approximated as a Gaussian wave packet (Szabo 2004, Tobocman et al 2002, Kharin et al 2003 though in the time domain the tailing edge falls slowly comparative to the leading edge. Thus, for our purpose in this paper we assume that the incident pulse is a normalized Gaussian wave packet.…”

Digitale Ultraschalldiagnostik der Unterschenkelvenenthrombose mit Harmonic Imaging und Cross-Beam-Technik

“…Weitere Möglichkeiten einer modifizierten Gefäßdarstellung im B-Bild sind mit dem sog. "spatial averaging", der Cross-Beam-Technik oder Sono-CT sowie mit Verfahren des "speckle reduction imaging" (SRI) verschiedene Stufen einer Bildhomogenisierung gegeben [27,28]. Dabei können diese neuartigen Verfahren durch eine modifizierte Darstellung des Weichteilgewebes zu einer Hervorhebung von Gefäßstruktu-ren und zu deren verbesserten Abgrenzbarkeit beitragen.…”