Using Low-Boiling Point Phase Change Contrast Agent Activation Signals for Super Resolution Ultrasound Localization Microscopy

DeRuiter, Ryan; Markley, Eric N.; Rojas, Juan D.; Pinton, Gianmarco; Dayton, Paul A.

doi:10.1109/ultsym.2019.8926020

Cited by 2 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During ND vaporization, the associated volume expansion leads to strong characteristic acoustic signatures with a narrowband frequency content [23]. Vaporization signals triggered by ADV [24], [25] and ODV [26], [27] were previously detected and super-localized in recent studies. However, in all these cases, the exact time at which the vaporization was triggered was known, making these an application of the Time of Arrival (ToA) problem, similar to ULM.…”

Section: Introductionmentioning

confidence: 99%

Passive Ultrasound Localization Microscopy of Nanodroplet Vaporizations During Proton Irradiation

Heymans

Collado-Lara

Rovituso³

et al. 2022

IEEE Open J. Ultrason., Ferroelect., Freq. Contr.

View full text Add to dashboard Cite

Superheated nanodroplets (NDs) were recently proposed for in vivo proton range verification, owing to their ability to vaporize into echogenic microbubbles (MBs) upon exposure to ionizing radiation. In a previous publication, vaporization events were detected with 2D Ultrasound Localization Microscopy (ULM) based on a pulse-echo method. Here, we introduce P-ULM, a passive version of ULM, based on the detection of acoustic signatures emitted by vaporizing NDs, without actively transmitting ultrasound. Due to the lack of a time reference for the trigger of the ND vaporization, the time differences of arrival to each transducer element are used to retrieve the position of vaporizing NDs. P-ULM, compared to ULM, can continuously detect and super-localize sparse radiation-induced vaporization events with inherent specificity against already existing microbubbles, which otherwise would hinder range verification in the presence of vascular flow. We evaluated the localization performances of both methods theoretically and experimentally, by interleaving active and passive acquisitions on ND-phantoms irradiated with protons. P-ULM offered a higher sensitivity to vaporizations, as it detected twice as many events as ULM. Both methods retrieved, in the acoustic lateral direction, the proton range and range dispersion with sub-millimeter accuracy. In the acoustic axial direction, despite a degraded theoretical resolution limit, P-ULM retrieved the proton spot size with an accuracy similar to ULM. Importantly, P-ULM detected vaporization events with high specificity in the presence of flowing MBs, which makes the technique a candidate for in vivo proton range verification in the presence of flow.

show abstract

Section: Introductionmentioning

confidence: 99%

Passive Ultrasound Localization Microscopy of Nanodroplet Vaporizations During Proton Irradiation

Heymans

Collado-Lara

Rovituso³

et al. 2022

IEEE Open J. Ultrason., Ferroelect., Freq. Contr.

View full text Add to dashboard Cite

show abstract

“…In addition, this method still requires long acquisition times (>100 ms) as the laser should operate at low repetition frequencies (∼10 Hz) to activate nanodroplets using safe laser powers. While nanodroplets of low boiling point fluorocarbons 18,19,21 (e.g., perfluorobutane) can be activated using low-intensity ultrasound pulses, controlling the vaporization and recondensation of low boiling point droplets is more challenging as nanodroplets can irreversibly form microbubbles at higher acoustic intensities. 23 Here we introduce a new localization-based ultrasound imaging method using blinking ultrasound-responsive nanoparticles (BNPs).…”

mentioning

confidence: 99%

“…In addition, as microbubbles cannot extravasate from the circulation due to their large size (∼1–10 μm), they are limited to vascular space . Perfluorocarbon nanodroplets can address the limitations of microbubble-based ultrasound localization imaging to some extent with their smaller size (typically 200 nm to 1 μm) and activatable ultrasound contrast. ,,,− Vaporization of the perfluorocarbon droplet cores and their subsequent recondensation generates a “blinking” ultrasound signal. , This blinking signal allows for faster localization of the contrast agents and, thus, shortens the acquisition times. When nanodroplets of high boiling point perfluorocarbons (e.g., perfluorohexane) are used, vaporization is typically achieved using laser pulses to induce a rapid temperature increase in the imaging region. , However, using a pulsed laser for droplet activation complicates the imaging setup and limits the imaging depth to the tissue penetration of laser pulses.…”

mentioning

confidence: 99%

Ultrafast Background-Free Ultrasound Imaging Using Blinking Nanoparticles

et al. 2023

View full text Add to dashboard Cite

Localization-based ultrasound imaging methods that use microbubbles or nanodroplets offer high-resolution imaging with improved sensitivity and reduced background signal. However, these methods require long acquisition times (typically seconds to minutes), preventing their use for real-time imaging and, thus, limiting their clinical translational potential. Here, we present a new ultrafast localization method using blinking ultrasound-responsive nanoparticles (BNPs). When activated with high frame rate (1 kHz) plane wave ultrasound pulses with a mechanical index of 1.5, the BNPs incept growth of micrometer-sized bubbles, which in turn collapse and generate a blinking ultrasound signal. We showed that background-free ultrasound images could be obtained by localizing these blinking events using acquisition times as low as 11 ms. In addition, we demonstrated that BNPs enable in vivo background-free ultrasound imaging in mice. We envision that BNPs will facilitate the clinical translation of localization-based ultrasound imaging for more sensitive detection of cancer and other diseases.

show abstract

Using Low-Boiling Point Phase Change Contrast Agent Activation Signals for Super Resolution Ultrasound Localization Microscopy

Cited by 2 publications

References 10 publications

Passive Ultrasound Localization Microscopy of Nanodroplet Vaporizations During Proton Irradiation

Passive Ultrasound Localization Microscopy of Nanodroplet Vaporizations During Proton Irradiation

Ultrafast Background-Free Ultrasound Imaging Using Blinking Nanoparticles

Contact Info

Product

Resources

About