Tissue harmonic synthetic aperture ultrasound imaging

Abstract

Synthetic aperture sequential beamforming (SASB) and tissue harmonic imaging (THI) are combined to improve the image quality of medical ultrasound imaging. The technique is evaluated in a comparative study against dynamic receive focusing (DRF). The objective is to investigate if SASB combined with THI improves the image quality compared to DRF-THI. The major benefit of SASB is a reduced bandwidth between the probe and processing unit. A BK Medical 2202 Ultraview ultrasound scanner was used to acquire beamformed RF data for offline evaluation. The acquisition was made interleaved between methods, and data were recorded with and without pulse inversion for tissue harmonic imaging. Data were acquired using a Sound Technology 192 element convex array transducer from both a wire phantom and a tissue mimicking phantom to investigate spatial resolution and penetration. In vivo scans were also performed for a visual comparison. The spatial resolution for SASB-THI is on average 19% better than DRI-THI, and the investigation of penetration showed equally good signal-to-noise ratio. In vivo B-mode scans were made and compared. The comparison showed that SASB-THI reduces the artifact and noise interference and improves image contrast and spatial resolution.

Effects of line fiducial parameters and beamforming on ultrasound calibration

“…In addition, SA tissue harmonic imaging has also been shown to improve image quality. 47 The impact of said techniques in in-situ calibration and their impact on FLE and TRE need future investigation. Moreover, SAI in tissue is susceptible to motion and phase aberration artifacts, caused by spatial variations of the speed of sound in tissue, which may lead to errors in focusing calculations in SAI and deteriorate image quality.…”

A Methodology for Anatomic Ultrasound Image Diagnostic Quality Assessment

“…Parameters were locked and intensity measurements were performed. Hemmsen et al [51] presents details of the study and its technical analysis.…”

Comparison of virtual source synthetic aperture beamforming with an element-based model

“…Perhaps the most widely used is the synthetic transmit aperture method, commonly referred to simply as synthetic aperture imaging (although this term can describe a broader class of methods; Jensen et al, 2006). By coherently combining the data from multiple transmit events with appropriate delays, a single improved image can be formed as if the transmit focus had been optimized throughout the image (Bae and Jeong, 2000;Frazier and O'Brien, 1998;Hemmsen et al, 2014;Nikolov and Jensen, 2002). This approach also extends to other transmit beam patterns such as diverging and plane waves, which has opened many new pulse sequencing possibilities (Gammelmark and Jensen, 2003;Karaman and O'Donnell, 1995;Montaldo et al, 2009;Tanter and Fink, 2014).…”