scholarly journals Waterproof Galvanometer Scanner-Based Handheld Photoacoustic Microscopy Probe for Wide-Field Vasculature Imaging In Vivo

Photonics ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 305
Author(s):  
Daewoon Seong ◽  
Sangyeob Han ◽  
Jaeyul Lee ◽  
Euimin Lee ◽  
Yoonseok Kim ◽  
...  
Keyword(s):  
Imaging Modality ◽  
Wide Field ◽  
Photoacoustic Microscopy ◽  
Label Free ◽  
Experimental Conditions ◽  
Sample Shape ◽  
Mouse Tissues ◽  
Wide Range ◽  
Galvanometer Scanner

Photoacoustic imaging (PAI) is a hybrid non-invasive imaging technique used to merge high optical contrast and high acoustic resolution in deep tissue. PAI has been extensively developed by utilizing its advantages that include deep imaging depth, high resolution, and label-free imaging. As a representative implementation of PAI, photoacoustic microscopy (PAM) has been used in preclinical and clinical studies for its micron-scale spatial resolution capability with high optical absorption contrast. Several handheld and portable PAM systems have been developed that improve its applicability to several fields, making it versatile. In this study, we developed a laboratory-customized, two-axis, waterproof, galvanometer scanner-based handheld PAM (WP-GVS-HH-PAM), which provides an extended field of view (14.5 × 9 mm2) for wide-range imaging. The fully waterproof handheld probe enables free movement for imaging regardless of sample shape, and volume rate and scanning region are adjustable per experimental conditions. Results of WP-GVS-HH-PAM-based phantom and in vivo imaging of mouse tissues (ear, iris, and brain) confirm the feasibility and applicability of our system as an imaging modality for various biomedical applications.

scholarly journals Recovery of photoacoustic images based on accurate ultrasound positioning

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yinhao Pan ◽  
Ningbo Chen ◽  
Liangjian Liu ◽  
Chengbo Liu ◽  
Zhiqiang Xu ◽  
...  
Keyword(s):  
Biological Tissue ◽  
Large Field ◽  
Photoacoustic Microscopy ◽  
Label Free ◽  
Imaging Data ◽  
Motor Speed ◽  
Image Correction ◽  
Microscopy Imaging ◽  
Scanning Method

AbstractPhotoacoustic microscopy is an in vivo imaging technology based on the photoacoustic effect. It is widely used in various biomedical studies because it can provide high-resolution images while being label-free, safe, and harmless to biological tissue. Polygon-scanning is an effective scanning method in photoacoustic microscopy that can realize fast imaging of biological tissue with a large field of view. However, in polygon-scanning, fluctuations of the rotating motor speed and the geometric error of the rotating mirror cause image distortions, which seriously affect the photoacoustic-microscopy imaging quality. To improve the image quality of photoacoustic microscopy using polygon-scanning, an image correction method is proposed based on accurate ultrasound positioning. In this method, the photoacoustic and ultrasound imaging data of the sample are simultaneously obtained, and the angle information of each mirror used in the polygon-scanning is extracted from the ultrasonic data to correct the photoacoustic images. Experimental results show that the proposed method can significantly reduce image distortions in photoacoustic microscopy, with the image dislocation offset decreasing from 24.774 to 10.365 μm.

scholarly journals Subwavelength-resolution label-free photoacoustic microscopy of optical absorption in vivo

2010 ◽  
Vol 35 (19) ◽  
pp. 3195 ◽  
Author(s):  
Chi Zhang ◽  
Konstantin Maslov ◽  
Lihong V. Wang
Keyword(s):  
Optical Absorption ◽  
Photoacoustic Microscopy ◽  
Label Free ◽  
Subwavelength Resolution

scholarly journals Optical Imaging of the Small Intestine Immune Compartments Across Scales

2021 ◽  
Author(s):  
Arielle Planchette ◽  
Cédric Schmidt ◽  
Olivier Burri ◽  
Mercedes Gomez de Agüero ◽  
Aleksandra Radenovic ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Small Intestine ◽  
High Resolution ◽  
Imaging Modality ◽  
Regions Of Interest ◽  
Label Free ◽  
3 Dimensional ◽  
Wide Range ◽  
Mouse Small Intestine ◽  
Made In

Abstract The limitations of 2D microscopy constrain our ability to observe and understand tissue-wide networks that are, by nature, 3-dimensional. Optical projection tomography enables the acquisition of large volumes (ranging from micrometres to centimetres) in various tissues, with label-free capacities for the observation of auto-fluorescent signals as well fluorescent-labelled targets of interest in multiple channels. We present a multi-modal workflow for the characterization of both structural and quantitative parameters of the mouse small intestine. As proof of principle, we evidence its applicability for imaging the mouse intestinal immune compartment and surrounding mucosal structures. We quantify the volumetric size and spatial distribution of Isolated Lymphoid Follicles (ILFs) and quantify density of villi throughout centimetre long segments of intestine. Furthermore, we exhibit the age- and microbiota-dependence for ILF development, and leverage a technique that we call reverse-OPT for identifying and homing in on regions of interest. Several quantification capabilities are displayed, including villous density in the autofluorescent channel and the size and spatial distribution of the signal of interest at millimetre-scale volumes. The concatenation of 3D image acquisition with the reverse-OPT sample preparation and a 2D high-resolution imaging modality adds value to interpretations made in 3D. This cross-modality referencing technique is found to provide accurate localisation of ROIs and to add value to interpretations made in 3D. Importantly, OPT may be used to identify sparsely-distributed regions of interest in large volumes whilst retaining compatibility with high-resolution microscopy modalities, including confocal microscopy. We believe this pipeline to be approachable for a wide-range of specialties, and to provide a new method for characterisation of the mouse intestinal immune compartment.

scholarly journals Laser scanning reflection-matrix microscopy for aberration-free imaging through intact mouse skull

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Seokchan Yoon ◽  
Hojun Lee ◽  
Jin Hee Hong ◽  
Yong-Sik Lim ◽  
Wonshik Choi
Keyword(s):  
Laser Scanning ◽  
Imaging Modality ◽  
Label Free ◽  
Intact Mouse ◽  
Sample Plane ◽  
Reflected Waves ◽  
Neuronal Dendrites ◽  
Reflection Matrix ◽  
Two Photon Fluorescence

AbstractA mouse skull is a barrier for high-resolution optical imaging because its thick and inhomogeneous internal structures induce complex aberrations varying drastically from position to position. Invasive procedures creating either thinned-skull or open-skull windows are often required for the microscopic imaging of brain tissues underneath. Here, we propose a label-free imaging modality termed laser scanning reflection-matrix microscopy for recording the amplitude and phase maps of reflected waves at non-confocal points as well as confocal points. The proposed method enables us to find and computationally correct up to 10,000 angular modes of aberrations varying at every 10 × 10 µm2 patch in the sample plane. We realized reflectance imaging of myelinated axons in vivo underneath an intact mouse skull, with an ideal diffraction-limited spatial resolution of 450 nm. Furthermore, we demonstrated through-skull two-photon fluorescence imaging of neuronal dendrites and their spines by physically correcting the aberrations identified from the reflection matrix.

scholarly journals Amyloid Beta: Multiple Mechanisms of Toxicity and Only Some Protective Effects?

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Paul Carrillo-Mora ◽  
Rogelio Luna ◽  
Laura Colín-Barenque
Keyword(s):  
Amyloid Beta ◽  
Protective Effects ◽  
Protective Mechanisms ◽  
Experimental Conditions ◽  
Mechanisms Of Toxicity ◽  
Mitochondrial Alterations ◽  
Physiological Properties ◽  
Wide Range

Amyloid beta (Aβ) is a peptide of 39–43 amino acids found in large amounts and forming deposits in the brain tissue of patients with Alzheimer’s disease (AD). For this reason, it has been implicated in the pathophysiology of damage observed in this type of dementia. However, the role of Aβin the pathophysiology of AD is not yet precisely understood. Aβhas been experimentally shown to have a wide range of toxic mechanismsin vivoandin vitro, such as excitotoxicity, mitochondrial alterations, synaptic dysfunction, altered calcium homeostasis, oxidative stress, and so forth. In contrast, Aβhas also shown some interesting neuroprotective and physiological properties under certain experimental conditions, suggesting that both physiological and pathological roles of Aβmay depend on several factors. In this paper, we reviewed both toxic and protective mechanisms of Aβto further explore what their potential roles could be in the pathophysiology of AD. The complete understanding of such apparently opposed effects will also be an important guide for the therapeutic efforts coming in the future.

scholarly journals Dual-Polarized Fiber Laser Sensor for Photoacoustic Microscopy

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4632 ◽  
Author(s):  
Lin ◽  
Liang ◽  
Jin ◽  
Wang
Keyword(s):  
Fiber Laser ◽  
Optical Resolution ◽  
High Sensitivity ◽  
Low Noise ◽  
Laser Sensor ◽  
Photoacoustic Microscopy ◽  
Label Free ◽  
Laser Sensors ◽  
Dual Polarized

Optical resolution photoacoustic microscopy (OR-PAM) provides high-resolution, label-free and non-invasive functional imaging for broad biomedical applications. Dual-polarized fiber laser sensors have high sensitivity, low noise, a miniature size, and excellent stability; thus, they have been used in acoustic detection in OR-PAM. Here, we review recent progress in fiber-laser-based ultrasound sensors for photoacoustic microscopy, especially the dual-polarized fiber laser sensor with high sensitivity. The principle, characterization and sensitivity optimization of this type of sensor are presented. In vivo experiments demonstrate its excellent performance in the detection of photoacoustic (PA) signals in OR-PAM. This review summarizes representative applications of fiber laser sensors in OR-PAM and discusses their further improvements.

scholarly journals Label-free photoacoustic microscopy for in-vivo tendon imaging using a fiber-based pulse laser

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Hwi Don Lee ◽  
Jun Geun Shin ◽  
Hoon Hyun ◽  
Bong-Ahn Yu ◽  
Tae Joong Eom
Keyword(s):  
Pulse Laser ◽  
Photoacoustic Microscopy ◽  
Label Free

In Vivo Behavior of Bioactive Glass-Based Hybrids in Animal Models For Bone Regeneration

2020 ◽  
Author(s):  
Shal N
Keyword(s):  
Bioactive Glass ◽  
Bone Regeneration ◽  
Bone Repair ◽  
Weight Bearing ◽  
Chemical Properties ◽  
Experimental Conditions ◽  
Wide Range ◽  
The Matrix ◽  
Hybrid Biomaterials

This review presents the recent advances and the current state-of-the-art of bioactive glass-based hybrid biomaterials for bone regeneration. Hybrid materials comprise two (or more) constituents at the nanometre scale, in which typically, one constituent is organic and functions as the matrix phase and the other constituent is inorganic and behaves as the filler phase. Such materials, thereby, more closely resemble natural bio-nanocomposites such as bone. Various glass compositions in combination with a wide range of natural and synthetic polymers have been evaluated in vivo under experimental conditions ranging from unloaded critical-sized defects to mechanically-loaded, weight-bearing sites with highly favourable outcomes. Additional possibilities include controlled release of anti-osteoporotic drugs, ions, antibiotics, pro-angiogenic substances and pro-osteogenic substances. Histological and morphological evaluations suggest the formation of new, highly vascularised bone that displays signs of remodelling over time. With the possibility to tailor the mechanical and chemical properties through careful selection of individual components, as well as the overall geometry (from mesoporous particles and micro-/nanospheres to 3D scaffolds and coatings) through innovative manufacturing processes, such biomaterials present exciting new avenues for bone repair and regeneration.

scholarly journals A new method for accurate in vivo mapping of human brain connections using microstructural and anatomical information

2020 ◽  
Vol 6 (31) ◽  
pp. eaba8245 ◽  
Author(s):  
Simona Schiavi ◽  
Mario Ocampo-Pineda ◽  
Muhamed Barakovic ◽  
Laurent Petit ◽  
Maxime Descoteaux ◽  
...  
Keyword(s):  
Human Brain ◽  
Imaging Modality ◽  
Brain Anatomy ◽  
Major Step ◽  
Wide Range ◽  
Noninvasive Imaging Modality ◽  
Novel Processing ◽  
Brain Data ◽  
Anatomical Information

Diffusion magnetic resonance imaging is a noninvasive imaging modality that has been extensively used in the literature to study the neuronal architecture of the brain in a wide range of neurological conditions using tractography. However, recent studies highlighted that the anatomical accuracy of the reconstructions is inherently limited and challenged its appropriateness. Several solutions have been proposed to tackle this issue, but none of them proved effective to overcome this fundamental limitation. In this work, we present a novel processing framework to inject into the reconstruction problem basic prior knowledge about brain anatomy and its organization and evaluate its effectiveness using both simulated and real human brain data. Our results indicate that our proposed method dramatically increases the accuracy of the estimated brain networks and, thus, represents a major step forward for the study of connectivity.

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