scholarly journals Photoacoustic Neuroimaging - Perspectives on a Maturing Imaging Technique and Its Applications in Neuroscience

2021 ◽  
Vol 15 ◽  
Author(s):  
Silviu-Vasile Bodea ◽  
Gil Gregor Westmeyer
Keyword(s):  
Photoacoustic Imaging ◽  
Imaging Techniques ◽  
Relevant Information ◽  
Nerve Fibers ◽  
Memory Storage ◽  
Network Activity ◽  
Imaging Method ◽  
Biological Engineering ◽  
Complementary Techniques ◽  
Molecular Contrast

A prominent goal of neuroscience is to improve our understanding of how brain structure and activity interact to produce perception, emotion, behavior, and cognition. The brain’s network activity is inherently organized in distinct spatiotemporal patterns that span scales from nanometer-sized synapses to meter-long nerve fibers and millisecond intervals between electrical signals to decades of memory storage. There is currently no single imaging method that alone can provide all the relevant information, but intelligent combinations of complementary techniques can be effective. Here, we thus present the latest advances in biomedical and biological engineering on photoacoustic neuroimaging in the context of complementary imaging techniques. A particular focus is placed on recent advances in whole-brain photoacoustic imaging in rodent models and its influential role in bridging the gap between fluorescence microscopy and more non-invasive techniques such as magnetic resonance imaging (MRI). We consider current strategies to address persistent challenges, particularly in developing molecular contrast agents, and conclude with an overview of potential future directions for photoacoustic neuroimaging to provide deeper insights into healthy and pathological brain processes.

Cardiovascular Imaging for Guiding Interventional Therapy in Structural Heart Diseases

2020 ◽  
Vol 16 (2) ◽  
pp. 111-122
Author(s):  
Nora Rat ◽  
Iolanda Muntean ◽  
Diana Opincariu ◽  
Liliana Gozar ◽  
Rodica Togănel ◽  
...  
Keyword(s):  
Heart Diseases ◽  
Interventional Procedure ◽  
Imaging Techniques ◽  
Ductus Arteriosus ◽  
Three Dimensional ◽  
High Specificity ◽  
Interventional Therapy ◽  
Structural Defects ◽  
Imaging Method ◽  
Three Dimensional Echocardiography

Development of interventional methods has revolutionized the treatment of structural cardiac diseases. Given the complexity of structural interventions and the anatomical variability of various structural defects, novel imaging techniques have been implemented in the current clinical practice for guiding the interventional procedure and for selection of the device to be used. Three– dimensional echocardiography is the most used imaging method that has improved the threedimensional assessment of cardiac structures, and it has considerably reduced the cost of complications derived from malalignment of interventional devices. Assessment of cardiac structures with the use of angiography holds the advantage of providing images in real time, but it does not allow an anatomical description. Transesophageal Echocardiography (TEE) and intracardiac ultrasonography play major roles in guiding Atrial Septal Defect (ASD) or Patent Foramen Ovale (PFO) closure and device follow-up, while TEE is the procedure of choice to assess the flow in the Left Atrial Appendage (LAA) and the embolic risk associated with a decreased flow. On the other hand, contrast CT and MRI have high specificity for providing a detailed description of structure, but cannot assess the flow through the shunt or the valvular mobility. This review aims to present the role of modern imaging techniques in pre-procedural assessment and intraprocedural guiding of structural percutaneous interventions performed to close an ASD, a PFO, an LAA or a patent ductus arteriosus.

Full-field X-ray diffraction microscopy using polymeric compound refractive lenses

2014 ◽  
Vol 47 (6) ◽  
pp. 1882-1888 ◽  
Author(s):  
J. Hilhorst ◽  
F. Marschall ◽  
T. N. Tran Thi ◽  
A. Last ◽  
T. U. Schülli
Keyword(s):  
Imaging Techniques ◽  
Light And Electron Microscopy ◽  
Added Value ◽  
Acquisition Time ◽  
Imaging Method ◽  
X Ray Diffraction ◽  
Polymeric Compound ◽  
Full Field ◽  
X Ray ◽  
Diffraction Imaging

Diffraction imaging is the science of imaging samples under diffraction conditions. Diffraction imaging techniques are well established in visible light and electron microscopy, and have also been widely employed in X-ray science in the form of X-ray topography. Over the past two decades, interest in X-ray diffraction imaging has taken flight and resulted in a wide variety of methods. This article discusses a new full-field imaging method, which uses polymer compound refractive lenses as a microscope objective to capture a diffracted X-ray beam coming from a large illuminated area on a sample. This produces an image of the diffracting parts of the sample on a camera. It is shown that this technique has added value in the field, owing to its high imaging speed, while being competitive in resolution and level of detail of obtained information. Using a model sample, it is shown that lattice tilts and strain in single crystals can be resolved simultaneously down to 10−3° and Δa/a= 10−5, respectively, with submicrometre resolution over an area of 100 × 100 µm and a total image acquisition time of less than 60 s.

scholarly journals Recent advances in applications of multimodal ultrasound-guided photoacoustic imaging technology

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Shanshan Wang ◽  
Yunfeng Zhao ◽  
Ye Xu
Keyword(s):  
Near Infrared ◽  
Photoacoustic Imaging ◽  
Imaging Techniques ◽  
Color Doppler ◽  
Power Doppler ◽  
Infrared Region ◽  
Detection Methods ◽  
Imaging Mode ◽  
Nonlinear Imaging ◽  
The Relationship

Abstract Photoacoustic imaging (PAI) is often performed simultaneously with ultrasound imaging and can provide functional and cellular information regarding the tissues in the anatomical markers of the imaging. This paper describes in detail the basic principles of photoacoustic/ultrasound (PA/US) imaging and its application in recent years. It includes near-infrared-region PA, photothermal, photodynamic, and multimode imaging techniques. Particular attention is given to the relationship between PAI and ultrasonic imaging; the latest high-frequency PA/US imaging of small animals, which involves not only B-mode, but also color Doppler mode, power Doppler mode, and nonlinear imaging mode; the ultrasonic model combined with PAI, including the formation of multimodal imaging; the preclinical imaging methods; and the most effective detection methods for clinical research for the future.

scholarly journals Tracking Transplanted Stem Cells Using Magnetic Resonance Imaging and the Nanoparticle Labeling Method in Urology

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jae Heon Kim ◽  
Hong J. Lee ◽  
Yun Seob Song
Keyword(s):  
Magnetic Resonance Imaging ◽  
Stem Cells ◽  
Molecular Imaging ◽  
Magnetic Resonance ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Image Resolution ◽  
Imaging Method ◽  
Resonance Imaging

A reliablein vivoimaging method to localize transplanted cells and monitor their viability would enable a systematic investigation of cell therapy. Most stem cell transplantation studies have used immunohistological staining, which does not provide information about the migration of transplanted cellsin vivoin the same host. Molecular imaging visualizes targeted cells in a living host, which enables determining the biological processes occurring in transplanted stem cells. Molecular imaging with labeled nanoparticles provides the opportunity to monitor transplanted cells noninvasively without sacrifice and to repeatedly evaluate them. Among several molecular imaging techniques, magnetic resonance imaging (MRI) provides high resolution and sensitivity of transplanted cells. MRI is a powerful noninvasive imaging modality with excellent image resolution for studying cellular dynamics. Several types of nanoparticles including superparamagnetic iron oxide nanoparticles and magnetic nanoparticles have been used to magnetically label stem cells and monitor viability by MRI in the urologic field. This review focuses on the current role and limitations of MRI with labeled nanoparticles for tracking transplanted stem cells in urology.

scholarly journals Respiratory-gated KES imaging of a rat model of acute lung injury at the Canadian Light Source

2017 ◽  
Vol 24 (3) ◽  
pp. 679-685 ◽  
Author(s):  
P. Deman ◽  
S. Tan ◽  
G. Belev ◽  
N. Samadi ◽  
M. Martinson ◽  
...  
Keyword(s):  
Lung Injury ◽  
Contrast Agent ◽  
Light Source ◽  
Imaging Techniques ◽  
Image Acquisition ◽  
Brown Norway ◽  
Pulmonary Vasculature ◽  
Imaging Method ◽  
Imaging Protocol ◽  
Iodinated Contrast

In this study, contrast-enhanced X-ray tomographic imaging for monitoring and quantifying respiratory disease in preclinical rodent models is proposed. A K-edge imaging method has been developed at the Canadian Light Source to very accurately obtain measurements of the concentration of iodinated contrast agent in the pulmonary vasculature and inhaled xenon in the airspaces of rats. To compare the iodine and xenon concentration maps, a scout projection image was acquired to define the region of interest within the thorax for imaging and to ensure the same locations were imaged in each K-edge subtraction (KES) acquisition. A method for triggering image acquisition based on the real-time measurements of respiration was also developed to obtain images during end expiration when the lungs are stationary, in contrast to other previously published studies that alter the respiration to accommodate the image acquisition. In this study, images were obtained in mechanically ventilated animals using physiological parameters at the iodine K-edge in vivo and at the xenon K-edge post mortem (but still under mechanical ventilation). The imaging techniques were performed in healthy Brown Norway rats and in age-matched littermates that had an induced lung injury to demonstrate feasibility of the imaging procedures and the ability to correlate the lung injury and the quantitative measurements of contrast agent concentrations between the two KES images. The respiratory-gated KES imaging protocol can be easily adapted to image during any respiratory phase and is feasible for imaging disease models with compromised lung function.

scholarly journals Imaging techniques in the assessment of endovascular infrarenal abdominal aortic repair

2020 ◽  
Vol 73 (1-2) ◽  
pp. 29-35
Author(s):  
Aleksandar Spasic ◽  
Viktor Till ◽  
Marijana Basta-Nikolic ◽  
Djordje Milosevic ◽  
Darka Hadnadjev-Simonji ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Computed Tomography Angiography ◽  
Imaging Techniques ◽  
First Year ◽  
Imaging Method ◽  
Diagnostic Modality ◽  
Aortic Repair ◽  
Abdominal Aortic ◽  
Enhanced Computed Tomography

Introduction. Imaging is essential in the assessment of endovascular infrarenal abdominal aortic repair results. Complications include endoleaks, graft migration, kinking and infolding, stenosis, occlusion, and secondary ruptures. Examination Modalities. Contemporary imaging strategies are based on using noninvasive imaging modalities. After endovascular infrarenal abdominal aortic repair, the standard evaluation modality is computed tomography angiography, whereas additional modalities include magnetic resonance imaging, ultrasonography, and radiography. However, although an invasive imaging method, digital subtraction angiography is still performed in some patients. Computed tomography angiography provides excellent contrast, spatial resolution, and exact measurements of structures of interest, which is essential in the follow-up. Follow-up Protocol. Currently recommended follow-up protocol in the first year is contrast- enhanced computed tomography imaging at 1 and 12 months after the procedure. Conclusion. Due to its characteristics, reproducibility and availability, computed tomography angiography remains the cornerstone diagnostic modality of post-procedural assessment in patients with endovascular infrarenal abdominal aortic repair.

scholarly journals Comparison between cystourethrography and sonourethrography in preoperative diagnostic management of patients with anterior urethral strictures

2018 ◽  
Vol 20 (4) ◽  
pp. 436
Author(s):  
Jakub Krukowski ◽  
Adam Kałużny ◽  
Jakub Kłącz ◽  
Marcin Matuszewski
Keyword(s):  
Imaging Techniques ◽  
Imaging Method ◽  
Urethral Strictures ◽  
Preoperative Diagnostic ◽  
Diagnostic Management ◽  
The Mean

Aim: To evaluate the urethral lesions and the degree of spongiofibrosis using cystourethrography (CUG) and sonourethrography (SUG) in order to propose the best imaging method for further surgical treatment.Material and methods: The study involved 66 patients with anterior urethral strictures with indication for urethroplasty. Results of CUG and SUG were compared with each other and data from surgical protocol.Results: Totally 72 strictures were detected; 47 in the bulbar part of urethra and 25 in the penile urethra. The mean length of the stenosis was 16.43 mm for CUG and 27.41 mm for SUG and 31.05 mm during surgery. The correlation levels between imaging techniques and intraoperative measurements were 0.55 (p<0.001) for CUG and 0.73 (p<0.001) for SUG. After dividing the strictures according to their location, better correlation for stenoses was obtained in penile urethra: 0.66 (p<0.001) for CUG and 0.86 (p<0.001) for SUG.Conclusions: SUG seems to be a simple and fast examination to evaluate urethral strictures. It is more accurate in comparison to CUG and gives a possibility to assess the spongiofibrosis. This information suggests that SUG can be a good complement to CUG in diagnosis of anterior urethtral strictures.

scholarly journals Rate and timing of cortical responses driven by separate sensory channels

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Hannes P Saal ◽  
Michael A Harvey ◽  
Sliman J Bensmaia
Keyword(s):  
Computational Model ◽  
Relevant Information ◽  
Nerve Fibers ◽  
The Other ◽  
Fiber Types ◽  
Neural Signals ◽  
Neuronal Populations ◽  
Cortical Responses ◽  
Behaving Monkeys ◽  
Sense Of Touch

The sense of touch comprises multiple sensory channels that each conveys characteristic signals during interactions with objects. These neural signals must then be integrated in such a way that behaviorally relevant information about the objects is preserved. To understand the process of integration, we implement a simple computational model that describes how the responses of neurons in somatosensory cortex—recorded from awake, behaving monkeys—are shaped by the peripheral input, reconstructed using simulations of neuronal populations that reproduce natural spiking responses in the nerve with millisecond precision. First, we find that the strength of cortical responses is driven by one population of nerve fibers (rapidly adapting) whereas the timing of cortical responses is shaped by the other (Pacinian). Second, we show that input from these sensory channels is integrated in an optimal fashion that exploits the disparate response behaviors of different fiber types.

scholarly journals The value of Contrast-Enhanced Ultrasound in the characterization of vascular pattern of solid pancreatic lesions

2015 ◽  
Vol 17 (1) ◽  
pp. 16 ◽  
Author(s):  
Melania Ardelean ◽  
Roxana Sirli ◽  
Ioan Sporea ◽  
Simona Bota ◽  
Mirela Danila ◽  
...  
Keyword(s):  
Gold Standard ◽  
Imaging Techniques ◽  
Late Phase ◽  
Reference Method ◽  
Pancreatic Tumors ◽  
Imaging Method ◽  
Contrast Imaging ◽  
Cross Sectional ◽  
Solid Lesions

The aim of our study was to evaluate the accuracy of CEUS in the characterization of pancreatic solid lesions, considering cross sectional imaging techniques (CE-CT/MRI) as the “gold standard” methods. Material and methods: We performed a retrospective, monocentric study that included 91 solid pancreatic lesions which were evaluated by CEUS and by a second- line contrast imaging technique (CT or MRI), considered as the reference method. Results: The rate of a conclusive diagnosis based on a typical enhancement pattern was 94% (78/83 cases). In 72 cases out of 83 (86.7%) there was a perfect concordance between CEUS and the “gold-standard” imaging method (CE-CT/MRI). In our study, 88% (73/83) of the pancreatic lesions were categorized as malignant due to their typical wash-out aspect in the late phase. The overall accuracy of CEUS for the differential diagnosis of solid pancreatic tumors was approximately 81%. The accuracy of CEUS for the diagnosis of hypoen- hancing pancreatic tumors was approximately 89.1%; while for the diagnosis of hyperenhancing pancreatic tumors it was ap- proximately 72.8%. Conclusion: CEUS allows the differentiation between hypo- vs. hyperenhancing pancreatic solid lesions, with a considerable diagnostic accuracy, a fundamental step in the precise diagnosis of pancreatic tumors.

scholarly journals Towards Clinical Translation of LED-Based Photoacoustic Imaging: A Review

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2484 ◽  
Author(s):  
Yunhao Zhu ◽  
Ting Feng ◽  
Qian Cheng ◽  
Xueding Wang ◽  
Sidan Du ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Photoacoustic Imaging ◽  
Imaging Techniques ◽  
Clinical Translation ◽  
Key Factors ◽  
Pilot Studies ◽  
History Of ◽  
Molecular Components ◽  
Clinical Potential

Photoacoustic imaging, with the capability to provide simultaneous structural, functional, and molecular information, is one of the fastest growing biomedical imaging modalities of recent times. As a hybrid modality, it not only provides greater penetration depth than the purely optical imaging techniques, but also provides optical contrast of molecular components in the living tissue. Conventionally, photoacoustic imaging systems utilize bulky and expensive class IV lasers, which is one of the key factors hindering the clinical translation of this promising modality. Use of LEDs which are portable and affordable offers a unique opportunity to accelerate the clinical translation of photoacoustics. In this paper, we first review the development history of LED as an illumination source in biomedical photoacoustic imaging. Key developments in this area, from point-source measurements to development of high-power LED arrays, are briefly discussed. Finally, we thoroughly review multiple phantom, ex-vivo, animal in-vivo, human in-vivo, and clinical pilot studies and demonstrate the unprecedented preclinical and clinical potential of LED-based photoacoustic imaging.

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