Current Development and Applications of Super-Resolution Ultrasound Imaging

Min

et al. 2022

Preprint

Measuring cellular and tissue mechanics inside intact living organisms is essential for interrogating the roles of force in physiological and disease processes, and is a major goal in the field of mechanobiology. However, existing biosensors for 3D tissue mechanics, primarily based on fluorescent emissions and deformable materials, are limited for in vivo measurement due to the limited light penetration and poor material stability inside intact, living organisms. While magneto-motive ultrasound (MMUS), which uses superparamagnetic nanoparticles as imaging contrast agents, has emerged as a promising modality for real-time in vivo imaging of tissue mechanics, it has poor sensitivity and spatiotemporal resolution. To overcome these limitations, we introduce magneto-gas vesicles (MGVs), a unique class of protein nanostructures based on gas vesicles and magnetic nanoparticles that produces differential ultrasound signals in response to varying mechanical properties of surrounding tissues. These hybrid protein nanostructures significantly improve signal strength and detection sensitivity. Furthermore, MGVs enable non-invasive, long-term, and quantitative measurement of mechanical properties within 3D tissues and organs in vivo. We demonstrated the performance of MGV-based mechano-sensors in vitro, in fibrosis models of organoids, and in vivo in mouse liver fibrosis models.

Section: Resultsmentioning

confidence: 99%

Magneto-acoustic protein nanostructures for non-invasive imaging of tissue mechanics in vivo

Min

et al. 2022

Preprint

“…Such improvements have brought important benefits in various imaging applications. It is worth recalling that ultrasound super-resolution is an emerging technique proposed to visualize vascular tissue and atherosclerotic regions with a spatial resolution beyond the acoustic diffraction limit [2,3]. Multi-frequency transducers have opened to superharmonic imaging to become a reality thanks to the possibility to receive signal from the nonlinear response of microbubble at high-order harmonics using high-frequency transducers [4].…”

Section: Ultrasound Imaging 21 Piezoelectric Transducers Technologymentioning

confidence: 99%

“…Having a high density (~5.8 g/cm 3 ) and effective atomic number (Z eff~5 0), CZT semiconductors confer a high attenuation power on incident radiations. They have a high energy resolution (<6% FWHM) compared to traditional NaI (~10% FWHM): this reduces the detection of scattering events, increasing the contrast-to-noise ratio (CNR) and spatial resolution.…”

Section: New Generation Photon Detectors: Czt Technologymentioning

confidence: 99%

The Core of Medical Imaging: State of the Art and Perspectives on the Detectors

et al. 2021

In this review, the roles of detectors in various medical imaging techniques were described. Ultrasound, optical (near-infrared spectroscopy and optical coherence tomography) and thermal imaging, magnetic resonance imaging, computed tomography, single-photon emission tomography, positron emission tomography were the imaging modalities considered. For each methodology, the state of the art of detectors mainly used in the systems was described, emphasizing new technologies applied.

2021 Conference on Lasers and Electro-Optics Europe &Amp; European Quantum Electronics Conference (CLEO/Europe-EQEC)

“…providing full complex spectral field knowledge 24 . The scientific question is whether a THz-TDS can be exploited to develop a deterministic approach to waveform synthesis (closely related to ultrasound or radiofrequency approaches 25,26 ). The idea is to extract sufficient information to obtain access to any scattering-allowed output field.…”

Section: A Full Time-domain Field-approachmentioning

confidence: 99%

Deterministic spatiotemporal focusing of terahertz waves through scattering media

Kumar

Cecconi

Pasquazi

et al. 2021

Scattering-assisted synthesis of broadband optical pulses is recognized to have a cross-disciplinary fundamental and application importance. Achieving full-waveform synthesis generally requires means for assessing the instantaneous electric field, i.e. the absolute electromagnetic phase. These are generally not accessible to established methodologies for scattering-assisted pulse envelope and phase shaping. The lack of field sensitivity also results in complex indirect approaches to evaluate the scattering space-time properties. The terahertz frequency domain potentially offers some distinctive new possibilities thanks to the availability of methods to perform absolute measurements of the scattered electric field, as opposed to optical intensity-based diagnostics. An interesting conceptual question is whether this additional degree of freedom can lead to different types of methodologies towards wave shaping and to a direct field-waveform control. In this work, we theoretically investigate a deterministic scheme to achieve broadband, spatiotemporal waveform control of terahertz fields mediated by a scattering medium. The direct field access via Time-Domain Spectroscopy enables a process in which the field and scattering matrix of the medium are assessed with minimal experimental efforts. Then, the illumination conditions for an arbitrary targeted output field waveform are deterministically determined. In addition, the complete field knowledge enables reconstructing field distributions with complex phase profiles, as in the case of phase-only masks and optical vortices, a significantly challenging task for traditional implementations at optical frequencies based on intensity measurements aided with interferometric techniques.