scholarly journals A Multilevel Probabilistic Cerenkov Luminescence Tomography Reconstruction Framework Based on Energy Distribution Density Region Scaling

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiao Wei ◽  
Hongbo Guo ◽  
Jingjing Yu ◽  
Xuelei He ◽  
Huangjian Yi ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Distribution Density ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Source Distribution ◽  
Imaging Method ◽  
Density Region ◽  
Model Mouse ◽  
Ill Posed

Cerenkov luminescence tomography (CLT) is a promising non-invasive optical imaging method with three-dimensional semiquantitative in vivo imaging capability. However, CLT itself relies on Cerenkov radiation, a low-intensity radiation, making CLT reconstruction more challenging than other imaging modalities. In order to solve the ill-posed inverse problem of CLT imaging, some numerical optimization or regularization methods need to be applied. However, in commonly used methods for solving inverse problems, parameter selection significantly influences the results. Therefore, this paper proposed a probabilistic energy distribution density region scaling (P-EDDRS) framework. In this framework, multiple reconstruction iterations are performed, and the Cerenkov source distribution of each reconstruction is treated as random variables. According to the spatial energy distribution density, the new region of interest (ROI) is solved. The size of the region required for the next operation was determined dynamically by combining the intensity characteristics. In addition, each reconstruction source distribution is given a probability weight value, and the prior probability in the subsequent reconstruction is refreshed. Last, all the reconstruction source distributions are weighted with the corresponding probability weights to get the final Cerenkov source distribution. To evaluate the performance of the P-EDDRS framework in CLT, this article performed numerical simulation, in vivo pseudotumor model mouse experiment, and breast cancer mouse experiment. Experimental results show that this reconstruction framework has better positioning accuracy and shape recovery ability and can optimize the reconstruction effect of multiple algorithms on CLT.

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

scholarly journals ECG-gated dynamic magnetic resonance imaging method for examination of the pig heart

2001 ◽  
Vol 49 (3) ◽  
pp. 275-284
Author(s):  
Zs. Petrási ◽  
R. Romvári ◽  
G. Bajzik ◽  
B. Fenyves ◽  
I. Repa ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Three Dimensional ◽  
Dynamic Magnetic Resonance Imaging ◽  
Imaging Method ◽  
Resonance Imaging ◽  
Dynamic Magnetic Resonance ◽  
Heart Cycle ◽  
The Right

A dynamic magnetic resonance imaging (MRI) method was developed for in vivo examination of the pig heart. Measurements were carried out on 15 meat-type pigs of different liveweight using a 1.5 T equipment. Inhalation anaesthesia was applied, then data acquisition was synchronised by ECG gating. Depending on the heart rate and heart size, in each case 8 to 10 slices and in each slice 8 to 14 phases were acquired prospectively according to one heart cycle. During the post-processing of the images the left and the right ventricular volumes were determined. The values measured at 106 kg liveweight are 2.5 times higher than those obtained at 22 kg, while the ejection fractions are equal. The calculated cardiac output values were 3.5 l (22 kg, 132 beats/min.), and 6.0 l (106 kg, 91 beats/min.), respectively. After measuring the wall thickness, the contraction values were also determined for the septum (70%), and for the anterior (61%), posterior (41%) and lateral (54%) walls of the left ventricle. Three-dimensional animated models of the ventricles were constructed. Based on the investigations performed, the preconditioning, the anaesthetic procedure, the specific details of ECG measurement and the correct MR imaging technique were worked out.

scholarly journals The use of confocal microscopy in experimental studies and clinical practice of an endocrinologist: modern opportunities

2019 ◽  
Vol 65 (3) ◽  
pp. 174-183
Author(s):  
Natalya G. Mokrysheva ◽  
Sergey L. Kiselev ◽  
Natalia V. Klementieva ◽  
Anna M. Gorbacheva ◽  
Ivan I. Dedov
Keyword(s):  
Confocal Microscopy ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Imaging Method ◽  
New Methods ◽  
Corneal Confocal Microscopy ◽  
Endocrine Ophthalmopathy ◽  
Fundamental Research

Confocal microscopy is a modern imaging method that provides ample opportunities for in vitro and in vivo research. The clinical part of the review focuses on well-established techniques, such as corneal confocal microscopy for the diagnosis of diabetic neuropathy or endocrine ophthalmopathy; new methods are briefly described (intraoperative evaluation of tissues obtained by removing pituitary adenomas, thyroid and parathyroid glands). In the part devoted to fundamental research, the use of confocal microscopy to characterize the colocalization of proteins, as well as three-dimensional intracellular structures and signaling pathways in vivo, is considered. Indicators of intracellular calcium are analyzed.

scholarly journals A Three-Dimensional Imaging Method for the Quantification and Localization of Dynamic Cell Tracking Posttransplantation

2021 ◽  
Vol 9 ◽  
Author(s):  
Fengfeng Lu ◽  
Xin Pan ◽  
Wencheng Zhang ◽  
Xin Su ◽  
Yuying Gu ◽  
...  
Keyword(s):  
Cell Transplantation ◽  
Cell Tracking ◽  
Bioluminescence Imaging ◽  
Three Dimensional ◽  
Functional Restoration ◽  
Imaging Method ◽  
Ct Scanner ◽  
Donor Cells ◽  
Dynamic Cell

Cell transplantation has been proposed as a promising therapeutic strategy for curing the diseases requiring tissue repairing and functional restoration. A preclinical method to systematically evaluate the fates of donor cells in recipients, spatially and temporally, is demanded for judging therapeutic potentials for the particularly designed cell transplantation. Yet, the dynamic cell tracking methodology for tracing transplanted cells in vivo is still at its early phase. Here, we created a practical protocol for dynamically tracking cell via a three-dimensional (3D) technique which enabled us to localize, quantify, and overall evaluate the transplanted hepatocytes within a liver failure mouse model. First, the capacity of 3D bioluminescence imaging for quantifying transplanted hepatocytes was defined. Images obtained from the 3D bioluminescence imaging module were then combined with the CT scanner to reconstruct structure images of host mice. With those reconstructed images, precise locations of transplanted hepatocytes in the liver of the recipient were dynamically monitored. Immunohistochemistry staining of transplanted cells, and the serology assay of liver panel of the host mice were applied to verify the successful engraftment of donor cells in the host livers. Our protocol was practical for evaluating the engraftment efficiency of donor cells at their preclinical phases, which is also applicable as a referable standard for studying the fates of other transplanted cells, such as stem cell-derived cell types, during preclinical studies with cell transplantation therapy.

scholarly journals Hybrid Multilevel Sparse Reconstruction for a Whole Domain Bioluminescence Tomography Using Adaptive Finite Element

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Jingjing Yu ◽  
Xiaowei He ◽  
Guohua Geng ◽  
Fang Liu ◽  
L. C. Jiao
Keyword(s):  
Finite Element ◽  
Adaptive Finite Element Method ◽  
Source Distribution ◽  
Adaptive Finite Element ◽  
Sparse Regularization ◽  
Bioluminescence Tomography ◽  
Reconstruction Scheme ◽  
Boundary Measurements ◽  
Ill Posed

Quantitative reconstruction of bioluminescent sources from boundary measurements is a challenging ill-posed inverse problem owing to the high degree of absorption and scattering of light through tissue. We present a hybrid multilevel reconstruction scheme by combining the ability of sparse regularization with the advantage of adaptive finite element method. In view of the characteristics of different discretization levels, two different inversion algorithms are employed on the initial coarse mesh and the succeeding ones to strike a balance between stability and efficiency. Numerical experiment results with a digital mouse model demonstrate that the proposed scheme can accurately localize and quantify source distribution while maintaining reconstruction stability and computational economy. The effectiveness of this hybrid reconstruction scheme is further confirmed within vivoexperiments.

scholarly journals In vivo three-dimensional evaluation of tumour hypoxia in nasopharyngeal carcinomas using FMT-CT and MSOT

2019 ◽  
Vol 47 (5) ◽  
pp. 1027-1038
Author(s):  
Wenhui Huang ◽  
Kun Wang ◽  
Yu An ◽  
Hui Meng ◽  
Yuan Gao ◽  
...  
Keyword(s):  
High Resolution ◽  
Early Stage ◽  
Three Dimensional ◽  
High Sensitivity ◽  
Immunohistochemical Analysis ◽  
Molecular Probe ◽  
Imaging Method ◽  
Tumour Hypoxia ◽  
Imaging Strategy

Abstract Purpose Accurate evaluation of hypoxia is particularly important in patients with nasopharyngeal carcinoma (NPC) undergoing radiotherapy. The aim of this study was to propose a novel imaging strategy for quantitative three-dimensional (3D) evaluation of hypoxia in a small animal model of NPC. Methods A carbonic anhydrase IX (CAIX)-specific molecular probe (CAIX-800) was developed for imaging of hypoxia. Mouse models of subcutaneous, orthotopic, and spontaneous lymph node metastasis from NPC (5 mice per group) were established to assess the imaging strategy. A multi-modality imaging method that consisted of a hybrid combination of fluorescence molecular tomography-computed tomography (FMT-CT) and multispectral optoacoustic tomography (MSOT) was used for 3D quantitative evaluation of tumour hypoxia. Magnetic resonance imaging, histological examination, and immunohistochemical analysis were used as references for comparison and validation. Results In the early stage of NPC (2 weeks after implantation), FMT-CT enabled precise 3D localisation of the hypoxia biomarker with high sensitivity. At the advanced stage (6 weeks after implantation), MSOT allowed multispectral analysis of the biomarker and haemoglobin molecules with high resolution. The combination of high sensitivity and high resolution from FMT-CT and MSOT could not only detect hypoxia in small-sized NPCs but also visualise the heterogeneity of hypoxia in 3D. Conclusions Integration of FMT-CT and MSOT could allow comprehensive and quantifiable evaluation of hypoxia in NPC. These findings may potentially benefit patients with NPC undergoing radiotherapy in the future.

scholarly journals Optimized murine lung preparation for detailed structural evaluation via micro-computed tomography

2012 ◽  
Vol 112 (1) ◽  
pp. 159-166 ◽  
Author(s):  
Dragoş M. Vasilescu ◽  
Lars Knudsen ◽  
Matthias Ochs ◽  
Ewald R. Weibel ◽  
Eric A. Hoffman
Keyword(s):  
In Vivo Imaging ◽  
Airway Pressure ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Imaging Method ◽  
Small Airways ◽  
Micro Computed Tomography ◽  
Vascular Perfusion ◽  
Murine Lung

Utilizing micro-X-ray CT (μCT) imaging, we sought to generate an atlas of in vivo and intact/ex vivo lungs from normal murine strains. In vivo imaging allows visualization of parenchymal density and small airways (15–28 μm/voxel). Ex vivo imaging of the intact lung via μCT allows for improved understanding of the three-dimensional lung architecture at the alveolar level with voxel dimensions of 1–2 μm. μCT requires that air spaces remain air-filled to detect alveolar architecture while in vivo structural geometry of the lungs is maintained. To achieve these requirements, a fixation and imaging methodology that permits nondestructive whole lung ex vivo μCT imaging has been implemented and tested. After in vivo imaging, lungs from supine anesthetized C57Bl/6 mice, at 15, 20, and 25 cmH2O airway pressure, were fixed in situ via vascular perfusion using a two-stage flushing system while held at 20 cmH2O airway pressure. Extracted fixed lungs were air-dried. Whole lung volume was acquired at 1, 7, 21, and >70 days after the lungs were dried and served as validation for fixation stability. No significant shrinkage was observed: +8.95% change from in vivo to fixed lung ( P = 0.12), −1.47% change from day 1 to day 7 ( P = 0.07), −2.51% change from day 1 to day 21 ( P = 0.05), and −4.90% change from day 1 to day 70 and thereafter ( P = 0.04). μCT evaluation showed well-fixed alveoli and capillary beds correlating with histological analysis. A fixation and imaging method has been established for μCT imaging of the murine lung that allows for ex vivo morphometric analysis, representative of the in vivo lung.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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