Rationale And Objectives: Although contrast-enhanced ultrasound imaging techniques such as harmonic imaging (HI) have evolved to reduce tissue signals using the nonlinear properties of the contrast agent, levels of background suppression have been mixed. Subharmonic imaging (SHI) offers near complete tissue suppression by centering the receive bandwidth at half the transmitting frequency. The aims of this study were to demonstrate the feasibility of three-dimensional (3D) SHI and to compare it to 3D HI.
Materials And Methods: Three-dimensional HI and SHI were implemented on a Logiq 9 ultrasound scanner with a 4D10L probe. Four-cycle SHI was implemented to transmit at 5.8 MHz and receive at 2.9 MHz, while two-cycle HI was implemented to transmit at 5 MHz and receive at 10 MHz. The ultrasound contrast agent Definity was imaged within a flow phantom and the lower pole of two canine kidneys in both HI and SHI modes. Contrast-to-tissue ratios and rendered images were compared offline.
Results: SHI resulted in significant improvement in contrast-to-tissue ratios relative to HI both in vitro (12.11 ± 0.52 vs 2.67 ± 0.77, P< .001) and in vivo (5.74 ± 1.92 vs 2.40 ± 0.48, P = .04). Rendered 3D subharmonic images provided better tissue suppression and a greater overall view of vessels in a flow phantom and canine renal vasculature.
Conclusions: The successful implementation of SHI in 3D allows imaging of vascular networks over a heterogeneous sample volume and should improve future diagnostic accuracy. Additionally, 3D SHI provides improved contrast-to-tissue ratios relative to 3D HI.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351552 | PMC |
| http://dx.doi.org/10.1016/j.acra.2012.02.015 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Imaging Microbubbles With Contrast-Enhanced Endobronchial Ultrasound.
Ultrasound Med Biol
January 2024
Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Materials Science & Engineering, University of Toronto, Toronto, ON, Canada; Department of Medical Imaging, University of Toronto, Toronto, ON, Canada. Electronic address:
Article Synopsis
- The study investigates the effectiveness of contrast-enhanced endobronchial ultrasound (CE-EBUS) in imaging microbubbles (MBs) for diagnosing non-small cell lung cancer by comparing it to other ultrasound systems.
- Using both in vitro (lab settings) and in vivo (live mice) experiments, the CE-EBUS demonstrated a similar ability to generate contrast-to-tissue ratios compared to clinical and pre-clinical systems.
- The results suggest that CE-EBUS may be a viable option for imaging lymph nodes in lung cancer patients, offering diagnostic quality comparable to established ultrasound technologies.
Superharmonic and Microultrasound Imaging With Plane Wave Beamforming Techniques.
IEEE Trans Ultrason Ferroelectr Freq Control
November 2023
Superharmonic contrast imaging (SpHI) suppresses tissue clutter and allows high-contrast visualization of the vasculature. An array-based dual-frequency (DF) probe has been developed for SpHI, integrating a 21-MHz, 256-element microultrasound imaging array with a 2-MHz, 32-element array to take advantage of the broadband nonlinear responses from microbubble (MB) contrast agents. In this work, ultrafast imaging with plane waves was implemented for SpHI to increase the acquisition frame rate.
View Article and Find Full Text PDFA comparative study on detection of polymer-shelled microbubbles by different excitation pulses.
J Acoust Soc Am
July 2023
Department of Biomedical Engineering and Health System, KTH Royal Institute of Technology, Stockholm, 10044, Sweden.
Contrast agents are widely used in ultrasound imaging. Many imaging techniques have been developed to improve the contrast between tissue and the agents, based on the nonlinear response of microbubbles. In this study, heterodyne excitation was introduced and was compared with traditional sinusoidal signal and chirp excitation for visualizing polymer-shelled microbubbles and degassed water in a tissue-mimicking phantom.
View Article and Find Full Text PDFContrast-Enhanced Imaging of Histotripsy Bubble Clouds Using Chirp-Coded Excitation and Volterra Filtering.
IEEE Trans Ultrason Ferroelectr Freq Control
September 2023
Histotripsy is a focused ultrasound therapy that ablates tissue via bubble cloud activity. Real-time ultrasound image guidance is used to ensure safe and effective treatment. Plane-wave imaging enables tracking of histotripsy bubble clouds at a high frame rate but lacks adequate contrast.
View Article and Find Full Text PDFContrast-enhanced ultrasound imaging using capacitive micromachined ultrasonic transducers.
J Acoust Soc Am
March 2023
Department of Health Technology, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Article Synopsis
- Capacitive micromachined ultrasonic transducers (CMUTs) have a nonlinear voltage-signal relationship that can hinder traditional contrast enhanced ultrasound (CEUS) techniques.
- A new three-pulse amplitude modulation (AM) sequence has been introduced to mitigate these issues, showing better results with CMUTs compared to the conventional methods.
- Experimental results indicate that CMUTs can produce effective CEUS images with minimal degradation in signal quality, achieving high contrast-to-tissue ratio improvements using this new sequence.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!