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1.
Nat Commun ; 12(1): 1478, 2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33674570

RESUMO

The recently introduced minimal photon fluxes (MINFLUX) concept pushed the resolution of fluorescence microscopy to molecular dimensions. Initial demonstrations relied on custom made, specialized microscopes, raising the question of the method's general availability. Here, we show that MINFLUX implemented with a standard microscope stand can attain 1-3 nm resolution in three dimensions, rendering fluorescence microscopy with molecule-scale resolution widely applicable. Advances, such as synchronized electro-optical and galvanometric beam steering and a stabilization that locks the sample position to sub-nanometer precision with respect to the stand, ensure nanometer-precise and accurate real-time localization of individually activated fluorophores. In our MINFLUX imaging of cell- and neurobiological samples, ~800 detected photons suffice to attain a localization precision of 2.2 nm, whereas ~2500 photons yield precisions <1 nm (standard deviation). We further demonstrate 3D imaging with localization precision of ~2.4 nm in the focal plane and ~1.9 nm along the optic axis. Localizing with a precision of <20 nm within ~100 µs, we establish this spatio-temporal resolution in single fluorophore tracking and apply it to the diffusion of single labeled lipids in lipid-bilayer model membranes.


Assuntos
Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Difusão , Desenho de Equipamento , Fluorescência , Corantes Fluorescentes , Processamento de Imagem Assistida por Computador , Fótons
2.
Medicine (Baltimore) ; 100(6): e24646, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33578590

RESUMO

ABSTRACT: MR tractography of the lumbosacral plexus (LSP) is challenging due to the difficulty of acquiring high quality data and accurately estimating the neuronal tracts. We proposed an algorithm for an accurate visualization and assessment of the major LSP bundles using the segmentation of the cauda equina as seed points for the initial starting area for the fiber tracking algorithm.Twenty-six healthy volunteers underwent MRI examinations on a 3T MR scanner using the phased array coils with optimized measurement protocols for diffusion-weighted images and coronal T2 weighted 3D short-term inversion recovery sampling perfection with application optimized contrast using varying flip angle evaluation sequences used for LSP fiber reconstruction and MR neurography (MRN).The fiber bundles reconstruction was optimized in terms of eliminating the muscle fibers contamination using the segmentation of cauda equina, the effects of the normalized quantitative anisotropy (NQA) and angular threshold on reconstruction of the LSP. In this study, the NQA parameter has been used for fiber tracking instead of fractional anisotropy (FA) and the regions of interest positioning was precisely adjusted bilaterally and symmetrically in each individual subject.The diffusion data were processed in individual L3-S2 nerve fibers using the generalized Q-sampling imaging algorithm. Data (mean FA, mean diffusivity, axial diffusivity and radial diffusivity, and normalized quantitative anisotropy) were statistically analyzed using the linear mixed-effects model. The MR neurography was performed in MedINRIA and post-processed using the maximum intensity projection method to demonstrate LSP tracts in multiple planes.FA values significantly decreased towards the sacral region (P < .001); by contrast, mean diffusivity, axial diffusivity, radial diffusivity and NQA values significantly increased towards the sacral region (P < .001).Fiber tractography of the LSP was feasible in all examined subjects and closely corresponded with the nerves visible in the maximum intensity projection images of MR neurography. Usage of NQA instead of FA in the proposed algorithm enabled better separation of muscle and nerve fibers.The presented algorithm yields a high quality reconstruction of the LSP bundles that may be helpful both in research and clinical practice.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Plexo Lombossacral/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Nervos Espinhais/diagnóstico por imagem , Adulto , Algoritmos , Anisotropia , Cauda Equina/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/instrumentação , Região Lombossacral/inervação , Masculino , Nervos Espinhais/anatomia & histologia
3.
Nat Commun ; 12(1): 882, 2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33563996

RESUMO

Photoacoustic computed tomography (PACT) has generated increasing interest for uses in preclinical research and clinical translation. However, the imaging depth, speed, and quality of existing PACT systems have previously limited the potential applications of this technology. To overcome these issues, we developed a three-dimensional photoacoustic computed tomography (3D-PACT) system that features large imaging depth, scalable field of view with isotropic spatial resolution, high imaging speed, and superior image quality. 3D-PACT allows for multipurpose imaging to reveal detailed angiographic information in biological tissues ranging from the rodent brain to the human breast. In the rat brain, we visualize whole brain vasculatures and hemodynamics. In the human breast, an in vivo imaging depth of 4 cm is achieved by scanning the breast within a single breath hold of 10 s. Here, we introduce the 3D-PACT system to provide a unique tool for preclinical research and an appealing prototype for clinical translation.


Assuntos
Imageamento Tridimensional/métodos , Técnicas Fotoacústicas/métodos , Tomografia Computadorizada por Raios X/métodos , Angiografia , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mama/irrigação sanguínea , Mama/diagnóstico por imagem , Desenho de Equipamento , Feminino , Neuroimagem Funcional , Humanos , Imageamento Tridimensional/instrumentação , Técnicas Fotoacústicas/instrumentação , Ratos , Tomografia Computadorizada por Raios X/instrumentação
4.
Nat Protoc ; 16(1): 532-560, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33318694

RESUMO

Various super-resolution imaging techniques have been developed to break the diffraction-limited resolution of light microscopy. However, it still remains challenging to obtain three-dimensional (3D) super-resolution information of structures and dynamic processes in live cells at high speed. We recently developed high-speed single-point edge-excitation sub-diffraction (SPEED) microscopy and its two-dimensional (2D)-to-3D transformation algorithm to provide an effective approach to achieving 3D sub-diffraction-limit information in subcellular structures and organelles that have rotational symmetry. In contrast to most other 3D super-resolution microscopy or 3D particle-tracking microscopy approaches, SPEED microscopy does not depend on complex optical components and can be implemented onto a standard inverted epifluorescence microscope. SPEED microscopy is specifically designed to obtain 2D spatial locations of individual immobile or moving fluorescent molecules inside sub-micrometer biological channels or cavities at high spatiotemporal resolution. After data collection, post-localization 2D-to-3D transformation is applied to obtain 3D super-resolution structural and dynamic information. The complete protocol, including cell culture and sample preparation (6-7 d), SPEED imaging (4-5 h), data analysis and validation through simulation (5-13 h), takes ~9 d to complete.


Assuntos
Imageamento Tridimensional/métodos , Microscopia de Fluorescência/métodos , Algoritmos , Animais , Desenho de Equipamento , Células HeLa , Humanos , Imageamento Tridimensional/economia , Imageamento Tridimensional/instrumentação , Camundongos , Microscopia de Fluorescência/economia , Microscopia de Fluorescência/instrumentação , Células NIH 3T3 , Fatores de Tempo
5.
Methods Mol Biol ; 2179: 199-224, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32939723

RESUMO

Coordinated cell movements drive embryonic development and tissue repair, and can also spread disease. Time-lapse microscopy is an integral part in the study of the cell biology of collective cell movements. Advances in imaging techniques enable monitoring dynamic cellular and molecular events in real time within living animals. Here, we demonstrate the use of spinning disk confocal microscopy to investigate coordinated cell movements and epithelial-to-mesenchymal-like transitions during embryonic wound closure in Drosophila. We describe image-based metrics to quantify the efficiency of collective cell migration. Finally, we show the application of super-resolution radial fluctuation microscopy to obtain multidimensional, super-resolution images of protrusive activity in collectively moving cells in vivo. Together, the methods presented here constitute a toolkit for the modern analysis of collective cell migration in living animals.


Assuntos
Movimento Celular , Rastreamento de Células/métodos , Embrião não Mamífero/citologia , Animais , Rastreamento de Células/instrumentação , Drosophila melanogaster , Transição Epitelial-Mesenquimal , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Limite de Detecção , Microscopia Confocal/instrumentação , Microscopia Confocal/métodos
6.
Methods Mol Biol ; 2179: 243-256, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32939725

RESUMO

In many solid tumors, collective cell invasion prevails over single-cell dissemination strategies. Collective modes of invasion often display specific front/rear cellular organization, where invasive leader cells arise from cancer cell populations or the tumor stroma. Collective invasion involves coordinated cellular movements which require tight mechanical crosstalk through specific combinations of cell-cell interactions and cell-matrix adhesions. Cancer Associated Fibroblasts (CAFs) have been recently reported to drive the dissemination of epithelial cancer cells through ECM remodeling and direct intercellular contact. However, the cooperation between tumor and stromal cells remains poorly understood. Here we present a simple spheroid invasion assay to assess the role of CAFs in the collective migration of epithelial tumor cells. This method enables the characterization of 3D spheroid invasion patterns through live cell fluorescent labeling combined with spinning disc microscopy. When embedded in extracellular matrix, the invasive strands of spheroids can be tracked and leader/follower organization of CAFs and cancer cells can be quantified.


Assuntos
Fibroblastos Associados a Câncer/fisiologia , Movimento Celular , Rastreamento de Células/métodos , Imageamento Tridimensional/métodos , Esferoides Celulares/fisiologia , Fibroblastos Associados a Câncer/citologia , Técnicas de Cultura de Células/métodos , Linhagem Celular Tumoral , Rastreamento de Células/instrumentação , Matriz Extracelular/química , Humanos , Imageamento Tridimensional/instrumentação , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Esferoides Celulares/citologia , Células Tumorais Cultivadas
8.
Anim Sci J ; 91(1): e13447, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32902039

RESUMO

Nest building is an instinctive behavior toward protection from predators, body temperature regulation, and courtship. Previously, we discovered that acute and chronic social defeat stress suppresses the onset of nest-building behavior in male mice (C57BL/6J). Here, we analyzed nest building and other behavioral deficits induced by acute social defeat stress (ASDS). We utilized a customized cage and specifically developed observational programs for nest building, social avoidance, and other behaviors using an infrared depth camera to acquire three-dimensional (3D) data of animal behavior (Negura system). We determined the volume of nesting materials from these 3D depth images. Mice exposed to ASDS showed increased spontaneous activities, decreased rearing, and delayed nest building; however, nest-building activity was gradually recovered during the dark period of the 24 hr observation interval. At the endpoint following 24 hr, the ASDS and control groups showed no differences in nest volumes. Furthermore, we observed the time courses of both nest building and social avoidance behaviors and their relationship using the Negura system. Our data demonstrated a weak positive correlation between nest-building delay and social avoidance in ASDS mice. The Negura system can observe various behaviors that reflect the effects of social defeat stress.


Assuntos
Aprendizagem da Esquiva , Técnicas de Observação do Comportamento/instrumentação , Imageamento Tridimensional/instrumentação , Relações Interpessoais , Comportamento de Nidação/fisiologia , Fotografação/instrumentação , Comportamento Social , Estresse Psicológico/psicologia , Animais , Técnicas de Observação do Comportamento/métodos , Doença Crônica , Modelos Animais de Doenças , Imageamento Tridimensional/métodos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Fotografação/métodos
10.
PLoS One ; 15(6): e0235169, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32579596

RESUMO

A country's cultural landscapes are an important part of its heritage. The growing need to identify, catalogue and preserve these resources has led to a rapid change in the management and inventorying of heritage in general and of cultural landscapes in particular. The main aim of this work is to develop and apply an updated and integrated methodology for capturing and processing geo-information for the digital documentation of cultural heritage. The proposed case study is the atomic garden in the Finca El Encín (Madrid), a singular space with unique biogeographical features created over 60 years ago. The results of the case study validate the method, consisting of an unmanned aerial platform equipped with sensors to obtain point clouds and aerial images in conjunction with point clouds and images captured with a terrestrial laser scanner.


Assuntos
Antropologia Cultural/métodos , Jardinagem/métodos , Jardins , Imageamento Tridimensional/métodos , Fotogrametria/métodos , Geografia , Humanos , Imageamento Tridimensional/instrumentação , Fotogrametria/instrumentação , Reprodutibilidade dos Testes , Espanha
11.
Nature ; 583(7814): 78-82, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32494011

RESUMO

Many animals build complex structures to aid in their survival, but very few are built exclusively from materials that animals create 1,2. In the midwaters of the ocean, mucoid structures are readily secreted by numerous animals, and serve many vital functions3,4. However, little is known about these mucoid structures owing to the challenges of observing them in the deep sea. Among these mucoid forms, the 'houses' of larvaceans are marvels of nature5, and in the ocean twilight zone giant larvaceans secrete and build mucus filtering structures that can reach diameters of more than 1 m6. Here we describe in situ laser-imaging technology7 that reconstructs three-dimensional models of mucus forms. The models provide high-resolution views of giant larvacean houses and elucidate the role that house structure has in food capture and predator avoidance. Now that tools exist to study mucus structures found throughout the ocean, we can shed light on some of nature's most complex forms.


Assuntos
Organismos Aquáticos/metabolismo , Muco/metabolismo , Urocordados/anatomia & histologia , Urocordados/metabolismo , Animais , Ciclo do Carbono , Comportamento Alimentar , Cadeia Alimentar , Imageamento Tridimensional/instrumentação , Lasers , Conformação Molecular , Muco/química , Oceanos e Mares , Comportamento Predatório , Água do Mar
13.
Phys Rev Lett ; 124(19): 198104, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32469536

RESUMO

The localization of point sources in optical microscopy enables nm-precision imaging of single-molecules and biological dynamics. We report a new method of localization microscopy using twin Airy beams that yields precise 3D localization with the key advantages of extended depth range, higher optical throughput, and potential for imaging higher emitter densities than are possible using other techniques. A precision of better than 30 nm was achieved over a depth range in excess of 7 µm using a 60×, 1.4 NA objective. An illustrative application to extended-depth-range blood-flow imaging in a live zebrafish is also demonstrated.


Assuntos
Imageamento Tridimensional/métodos , Microscopia/métodos , Animais , Cloaca/irrigação sanguínea , Imageamento Tridimensional/instrumentação , Microscopia/instrumentação , Imagem Molecular/instrumentação , Imagem Molecular/métodos , Fluxo Sanguíneo Regional , Peixe-Zebra
14.
Nat Methods ; 17(6): 571-581, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32284609

RESUMO

Temporal focusing, with its ability to focus light in time, enables scanless illumination of large surface areas at the sample with micrometer axial confinement and robust propagation through scattering tissue. In conventional two-photon microscopy, widely used for the investigation of intact tissue in live animals, images are formed by point scanning of a spatially focused pulsed laser beam, resulting in limited temporal resolution of the excitation. Replacing point scanning with temporally focused widefield illumination removes this limitation and represents an important milestone in two-photon microscopy. Temporal focusing uses a diffusive or dispersive optical element placed in a plane conjugate to the objective focal plane to generate position-dependent temporal pulse broadening that enables axially confined multiphoton absorption, without the need for tight spatial focusing. Many techniques have benefitted from temporal focusing, including scanless imaging, super-resolution imaging, photolithography, uncaging of caged neurotransmitters and control of neuronal activity via optogenetics.


Assuntos
Imageamento Tridimensional/métodos , Iluminação/métodos , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Fótons , Animais , Desenho de Equipamento , Aumento da Imagem/instrumentação , Imageamento Tridimensional/instrumentação , Iluminação/instrumentação , Microscopia de Fluorescência por Excitação Multifotônica/instrumentação
15.
Eur J Vasc Endovasc Surg ; 60(1): 135-143, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32312666

RESUMO

OBJECTIVE: Fiber Optic RealShape (FORS) is a new technology platform that enables real time three dimensional (3D) visualisation of endovascular guidewires and catheters, based on the concepts of fibre optic technology instead of fluoroscopy. Anatomical context is provided by means of co-registered prior anatomical imaging, such as digital subtraction angiography or computed tomography. This preclinical study assesses the safety and feasibility of FORS technology. METHODS: Six physicians performed endovascular tasks in a phantom model and a porcine model using FORS enabled floppy guidewires, Cobra-2 catheters and Berenstein catheters. Each physician performed a set of predefined tasks in both models, including setup of the FORS system, device registration, and 12 aortic and peripheral target vessel cannulation tasks. The evaluation of the FORS system was based on (i) target vessel cannulation success; (ii) safety assessment; (iii) the accuracy of the FORS based device visualisation; and (iv) user experience. RESULTS: Successful cannulation was achieved in 72 of the 72 tasks (100%) in the phantom model and in 70 of the 72 tasks (97%) in the porcine model. No safety issues were reported. The FORS based device visualisation had a median offset at the tip of 2.2 mm (interquartile range 1.2-3.8 mm). The users judged the FORS based device visualisation to be superior to conventional fluoroscopic imaging, while not affecting the mechanical properties (torquability, pushability) of the FORS enabled guidewire and catheters. CONCLUSION: The combined outcomes of high cannulation success, positive user experience, adequate accuracy, and absence of safety issues demonstrate the safety and feasibility of the FORS system in a preclinical environment. FORS technology has great potential to improve device visualisation in endovascular interventions.


Assuntos
Procedimentos Endovasculares/instrumentação , Tecnologia de Fibra Óptica , Imageamento Tridimensional/instrumentação , Dispositivos de Acesso Vascular , Animais , Vasos Sanguíneos/diagnóstico por imagem , Vasos Sanguíneos/patologia , Cateterismo Periférico/instrumentação , Cateterismo Periférico/métodos , Procedimentos Endovasculares/métodos , Feminino , Tecnologia de Fibra Óptica/métodos , Humanos , Imageamento Tridimensional/métodos , Suínos
16.
Nat Nanotechnol ; 15(6): 500-506, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32313220

RESUMO

Capturing the dynamics of live cell populations with nanoscale resolution poses a significant challenge, primarily owing to the speed-resolution trade-off of existing microscopy techniques. Flow cytometry would offer sufficient throughput, but lacks subsample detail. Here we show that imaging flow cytometry, in which the point detectors of flow cytometry are replaced with a camera to record 2D images, is compatible with 3D localization microscopy through point-spread-function engineering, which encodes the depth of the emitter into the emission pattern captured by the camera. The extraction of 3D positions from sub-cellular objects of interest is achieved by calibrating the depth-dependent response of the imaging system using fluorescent beads mixed with the sample buffer. This approach enables 4D imaging of up to tens of thousands of objects per minute and can be applied to characterize chromatin dynamics and the uptake and spatial distribution of nanoparticles in live cancer cells.


Assuntos
Citometria de Fluxo/instrumentação , Microscopia de Fluorescência/instrumentação , Imagem Óptica/instrumentação , Desenho de Equipamento , Humanos , Imageamento Tridimensional/instrumentação , Nanopartículas/análise , Saccharomyces cerevisiae/citologia , Linfócitos T/citologia
17.
PLoS One ; 15(4): e0232193, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348334

RESUMO

Insect wings are highly evolved structures with aerodynamic and structural properties that are not fully understood or systematically modeled. Most species in the insect order Odonata have permanently deployed high aspect ratio wings. Odonata have been documented to exhibit extraordinary flight performance and a wide range of interesting flight behaviors that rely on agility and efficiency. The characteristic three-dimensional corrugated structures of these wings have been observed and modeled for a small number of species, with studies showing that corrugations can provide significant aerodynamic and structural advantages. Comprehensive museum collections are the most practical source of Odonata wing, despite the risk of adverse effects caused by dehydration and preservation of specimens. Museum specimens are not to be handled or damaged and are best left undisturbed in their display enclosures. We have undertaken a systematic process of scanning, modeling, and post-processing the wings of over 80 Odonata species using a novel and accurate method and apparatus we developed for this purpose. The method allows the samples to stay inside their glass cases if necessary and is non-destructive. The measurements taken have been validated against micro-computed tomography scanning and against similar-sized objects with measured dimensions. The resulting publicly available dataset will allow aeronautical analysis of Odonata aerodynamics and structures, the study of the evolution of functional structures, and research into insect ecology. The technique is useable for other orders of insects and other fragile samples.


Assuntos
Odonatos/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Bases de Dados Factuais , Voo Animal/fisiologia , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Microscopia Eletrônica de Varredura , Modelos Anatômicos , Museus , Odonatos/classificação , Odonatos/fisiologia , Fotogrametria/instrumentação , Austrália do Sul , Asas de Animais/fisiologia , Asas de Animais/ultraestrutura , Microtomografia por Raio-X
18.
PLoS One ; 15(4): e0221071, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32275668

RESUMO

PURPOSE: To accelerate the acquisition of free-breathing 3D saturation-recovery-based (SASHA) myocardial T1 mapping by acquiring fewer saturation points in combination with a post-processing 3D denoising technique to maintain high accuracy and precision. METHODS: 3D SASHA T1 mapping acquires nine T1-weighted images along the saturation recovery curve, resulting in long acquisition times. In this work, we propose to accelerate conventional cardiac T1 mapping by reducing the number of saturation points. High T1 accuracy and low standard deviation (as a surrogate for precision) is maintained by applying a 3D denoising technique to the T1-weighted images prior to pixel-wise T1 fitting. The proposed approach was evaluated on a T1 phantom and 20 healthy subjects, by varying the number of T1-weighted images acquired between three and nine, both prospectively and retrospectively. Following the results from the healthy subjects, three patients with suspected cardiovascular disease were acquired using five T1-weighted images. T1 accuracy and precision was determined for all the acquisitions before and after denoising. RESULTS: In the T1 phantom, no statistical difference was found in terms of accuracy and precision for the different number of T1-weighted images before or after denoising (P = 0.99 and P = 0.99 for accuracy, P = 0.64 and P = 0.42 for precision, respectively). In vivo, both prospectively and retrospectively, the precision improved considerably with the number of T1-weighted images employed before denoising (P<0.05) but was independent on the number of T1-weighted images after denoising. CONCLUSION: We demonstrate the feasibility of accelerating 3D SASHA T1 mapping by reducing the number of acquired T1-weighted images in combination with an efficient 3D denoising, without affecting accuracy and precision of T1 values.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Coração/diagnóstico por imagem , Imageamento Tridimensional/métodos , Imagem por Ressonância Magnética/métodos , Humanos , Imageamento Tridimensional/economia , Imageamento Tridimensional/instrumentação , Imagem por Ressonância Magnética/economia , Imagem por Ressonância Magnética/instrumentação , Imagens de Fantasmas , Estudos Retrospectivos
19.
PLoS One ; 15(3): e0230821, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32231378

RESUMO

PURPOSE: Using 4D magnetic particle imaging (MPI), intravascular optical coherence tomography (IVOCT) catheters are tracked in real time in order to compensate for image artifacts related to relative motion. Our approach demonstrates the feasibility for bimodal IVOCT and MPI in-vitro experiments. MATERIAL AND METHODS: During IVOCT imaging of a stenosis phantom the catheter is tracked using MPI. A 4D trajectory of the catheter tip is determined from the MPI data using center of mass sub-voxel strategies. A custom built IVOCT imaging adapter is used to perform different catheter motion profiles: no motion artifacts, motion artifacts due to catheter bending, and heart beat motion artifacts. Two IVOCT volume reconstruction methods are compared qualitatively and quantitatively using the DICE metric and the known stenosis length. RESULTS: The MPI-tracked trajectory of the IVOCT catheter is validated in multiple repeated measurements calculating the absolute mean error and standard deviation. Both volume reconstruction methods are compared and analyzed whether they are capable of compensating the motion artifacts. The novel approach of MPI-guided catheter tracking corrects motion artifacts leading to a DICE coefficient with a minimum of 86% in comparison to 58% for a standard reconstruction approach. CONCLUSIONS: IVOCT catheter tracking with MPI in real time is an auspicious method for radiation free MPI-guided IVOCT interventions. The combination of MPI and IVOCT can help to reduce motion artifacts due to catheter bending and heart beat for optimized IVOCT volume reconstructions.


Assuntos
Artefatos , Cateteres , Imageamento Tridimensional/instrumentação , Movimento , Tomografia de Coerência Óptica/instrumentação , Imagens de Fantasmas
20.
J Craniofac Surg ; 31(4): 950-955, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32149975

RESUMO

BACKGROUND: Mandibular reconstruction is considered one of the most complex reconstructive surgeries in the field of craniomaxillofacial surgery. With the introduction of microvascular reconstructive surgery, free fibula flap become the gold standard for reconstruction of mandibular defects. For optimum restoration of the patient's esthetics and function, the free fibular flap should be recontoured to follow the natural premorbid state of the mandible. Virtual surgical planning using preoperative computed tomographic (CT) data can be rendered into 3-dimensional (3D) model for digitalized simulation of the bony resection and reconstruction with reported high accuracy. METHODS: Ten patients were included in the study for delayed mandibular reconstruction using free fibular flap. For all the patients, preoperative CT scan for the skull and lower limbs were obtained and integrated into the software for virtual planning and guides fabrications. Postoperative CT was obtained and rendered 3D model to be superimposed on the preoperative record for assessment of the virtual planning accuracy by different linear and angular measurements. RESULTS: No statistically significant difference was found between virtual group and postoperative group where P = 0.067, regarding average of linear measurements of all patients. Statistically significant difference was found between virtual group and postoperative group in measurements from axial plane where P = 0.004. No statistically significant difference was found between virtual group and postoperative group where P = 0.723, regarding angles between fibular segments. CONCLUSION: Virtual surgical planning for mandibular reconstruction offers high reproducibility and precision, reducing the side errors, besides its time saving advantage for both the operator and the patient.


Assuntos
Retalhos de Tecido Biológico/cirurgia , Imageamento Tridimensional , Mandíbula/cirurgia , Reconstrução Mandibular , Cirurgia Assistida por Computador , Adolescente , Adulto , Feminino , Fíbula/diagnóstico por imagem , Fíbula/cirurgia , Humanos , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/métodos , Masculino , Mandíbula/diagnóstico por imagem , Período Pós-Operatório , Reprodutibilidade dos Testes , Software , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos , Tomografia Computadorizada por Raios X , Adulto Jovem
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