Three-dimensional Imaging Technique Research Articles

Three-dimensional imaging of acoustic pressure by tomography applied to optical feedback interferometry

This paper presents a novel experimental technique for three-dimensional imaging of acoustic pressure waves by means of an optical feedback interferometer associated to standard Radon transformation algorithm for tomography. The imaging system is based on the sensing of the optical refractive index changes induced by the pressure variation in the medium where the acoustic wave propagates. Thanks to the compactness allowed by the laser optical feedback interferometer, this technique allows to image in three dimensions the variations of pressure of any acoustic source without any displacement of the source.

Endodontic Management of Dens in Dente – A Systematic Review of Case Reports and Case Series

ABSTRACT Objective: Dens in dente is a developmental dental malformation with various anatomical traits that make treatment difficult. The importance of a timely and correct diagnosis in determining the most effective treatment approach cannot be overstated. Using three-dimensional (3D) imaging techniques has improved the diagnosis of teeth with complex anatomies, such as dens in dente. This systematic review aimed to determine the different techniques for endodontic management of teeth with Dens in dente having periapical lesions. Materials and Methods: Case reports and case series were identified in databases - PubMed-MEDLINE, Google Scholar, Research Gate, EBSCO-Host, Scopus, and Cochrane Library based on title, abstract, and full text published in the English language between January 1, 2016 and April 30, 2023. Patients who have periapical lesions and dens in dente in their permanent teeth and reporting on the results of nonsurgical or surgical intervention in terms of healing were eligible for this review, while editorial reviews, review papers, abstracts, letters to the editor, and animal studies are all excluded. Case studies on deciduous teeth, dens in dente retreatment, or dens associated with other developmental disorders are also excluded. Three authors evaluated the quality of the included studies. The quality of the included case reports and case series was evaluated using the Joanna Briggs Institute’s Critical Appraisal Checklist for Case Reports and Case Series. Results and Discussion: A total of 28 articles were suitable for inclusion, with 24 case reports and 4 case series. According to the available evidence, the condition is linked to an increased prevalence of pulp disease. Any necessary endodontic treatment may be difficult due to the aberrant anatomy. Early identification and preventive intervention rescued the teeth from further dental diseases. Conclusion: Nevertheless, thorough diagnoses and treatment planning are essential. Maintaining the vitality of the pulp or conserving the tooth using the least invasive way is the guiding principle when choosing a treatment modality. A surgical approach is only needed if the conservative approach fails. In the current systematic review, all cases showed reduction in the size of the periapical lesion or complete periapical healing.

Tissue clearing and imaging approaches for in toto analysis of the reproductive system†.

New microscopy techniques in combination with tissue clearing protocols and emerging analytical approaches have presented researchers with the tools to understand dynamic biological processes in a three-dimensional context. This paves the road for the exploration of new research questions in reproductive biology, for which previous techniques have provided only approximate resolution. These new methodologies now allow for contextualized analysis of far-larger volumes than was previously possible. Tissue optical clearing and three-dimensional imaging techniques posit the bridging of molecular mechanisms, macroscopic morphogenic development, and maintenance of reproductive function into one cohesive and comprehensive understanding of the biology of the reproductive system. In this review, we present a survey of the various tissue clearing techniques and imaging systems, as they have been applied to the developing and adult reproductive system. We provide an overview of tools available for analysis of experimental data, giving particular attention to the emergence of artificial intelligence-assisted methods and their applicability to image analysis. We conclude with an evaluation of how novel image analysis approaches that have been applied to other organ systems could be incorporated into future experimental evaluation of reproductive biology.

URBAN 3D RECONSTRUCTION OF VHR SAR IMAGES USING ITERATIVE OPTIMIZATION ALGORITHM AND LAYOVER FIXED-ORDER MODEL

Abstract. Synthetic Aperture Radar (SAR) Tomography (TomoSAR) is a three-dimensional SAR imaging technique that uses multiple passes to process complex SAR images and obtain three-dimensional spatial scattering information to derive the elevation scattering distribution. Due to its own shortcomings, the elevation obtained by the traditional spectral estimation method has low resolution in the elevation direction and is affected by noise. The imaging algorithm based on compressed sensing can achieve super-resolution reconstruction in the elevation direction while reducing the number of observations. However, the CS algorithm still faces challenges when applied to real-world tomographic SAR imaging. In particular, it often requires numerous iterations to achieve satisfactory results, which significantly reduces its processing efficiency in large-scale tomography. To address the above issues, in this paper, we proposed an urban 3D reconstruction of VHR SAR images using an iterative optimization algorithm and layover fixed-order model. The iterative optimization algorithm and the layover fixed-order model consist of two parts: The TomoSAR imaging equation is solved by the two-step iterative shrinkage/thresholding (TwIST) algorithm, and the number of scatterers K is estimated by the Bayesian Information Criterion (BIC). In this paper, the effectiveness of TwIST-BIC in TomoSAR imaging in urban areas is verified with real TerraSARX data. By comparing with the OMP algorithm based on matching tracking and the FISTA algorithm based on gradient descent. The TWIST-BIC method is less complex, converges faster, and combines both execution speed and super-resolution, which can effectively solve the processing efficiency problem in large-area tomography and acquire high-resolution tomographic analysis.

Three-dimensional refractive index microscopy based on the multi-layer propagation model with obliquity factor correction

Multi-layer propagation model-based intensity diffraction tomography (IDT) is a three-dimensional (3D) microscopy imaging technique to reveal the structural information of optically thick or multiple scattering samples. However, the performance of existing multi-layer propagation models deteriorates with increasing illumination angle, which can prevent good 3D refractive index (RI) imaging. To overcome this limitation, we incorporate the obliquity factor (OF) into the multi-layer propagation model. Numerical simulation validates that the forward propagation and the RI reconstruction both can be considerably improved. Then, the 3D RI reconstruction performance is quantitatively and qualitatively validated by optical experiments on polystyrene microspheres and peony pollen grains, respectively. In addition, excellent optical sectioning and high spatial resolution are experimentally demonstrated on various unlabeled fixed and living samples, including an Arabidopsis root, HeLa and HCT-116 cells. Time-lapse 3D imaging of living samples is performed for the first time for multi-layer propagation model-based IDT, demonstrating its potential application to some biological and medical studies.

The Flatness Error Evaluation of Metal Workpieces Based on Line Laser Scanning Digital Imaging Technology

With the development of intelligent manufacturing, the production and assembly accuracy of components in factories is increasing in line with growing demand. However, the traditional manual quality inspection is inefficient, inaccurate, and costly. To this end, digital and optical imaging techniques are used to achieve intelligent quality inspection. However, during the reconstruction process, the high reflectivity of object materials affects the speed and accuracy of reconstruction results. To overcome these problems, this study investigated the three-dimensional (3D) digital imaging techniques based on line laser scanning. It advances a novel methodology for image segmentation, underpinned by deep learning algorithms, to augment the precision of the reconstruction results while simultaneously enhancing processing velocity. After the reconstruction phase, the research assesses flatness tolerance using point cloud registration technology. Finally, we constructed a measurement platform with a cost of less than CNY 100,000 (about USD 14,000) and obtained a measurement accuracy of 30 microns.

Double field-of-view single-shot common-path off-axis reflective digital holographic microscope

Digital holography is a versatile three-dimensional imaging technique that has the ability to record the complex wave-front of an imaged object in two-dimensions and retrieve it in three-dimensions. Several technical challenges of digital holographic systems have been overcome by proposing single-shot acquisition and common-path configurations. However, the limited fiel-of-view (FOV) of digital holography is the most fundamental and technically challenging aspect of this technology. With this in mind, we have developed a digital holographic microscope (DHM) with a doubled FOV together with it leverages single-shot acquisition, common-path, and off-axis configuration and operates in the reflection mode. The double FOV is achieved by spatial frequency multiplexing of two different areas of the object beam by the use of a cube beam splitter. The common-path and off-axis configuration are obtained by employing a plate beam splitter just before the microscope objective. Several experiments are carried out, and the results are presented to demonstrate the validity and effectiveness of the proposed DHM for quantitative phase imaging of (semi) transparent and reflective objects. Based on the experimental results, the proposed microscope shows advanced performance in biomedical imaging as well as inspection of engineered surfaces with its simplicity, higher stability (temporal and mechanical), compactness, low cost, and most importantly double FOV capabilities.

Subsurface imaging dataset acquired at the Garner Valley Downhole Array site using a dense network of three-component nodal stations

There is a growing need to characterize the engineering material properties of the shallow subsurface in three dimensions for advanced engineering analyses. However, imaging the near-surface in three dimensions at spatial resolutions required for such purposes remains in its infancy and requires further study before it can be adopted into practice. To enable and accelerate research in this area, we present a large subsurface imaging data set acquired using a dense network of three-component (3C) nodal stations acquired in 2019 at the Garner Valley Downhole Array (GVDA) site. Acquisition of this data set involved the deployment of 196 stations positioned on a 14 × 14 grid with a 5 m spacing. The array was used to acquire active-source data generated by a vibroseis truck and an instrumented sledgehammer, and passive-wavefield data containing ambient noise. The active-source acquisition included 66 vibroseis and 209 instrumented sledgehammer source locations. Multiple source impacts were recorded at each source location to enable stacking of the recorded signals. The active-source recordings are provided in terms of both raw, uncorrected units of counts and corrected engineering units of meters per second. For each source impact, the force output from the vibroseis or instrumented sledgehammer was recorded and is provided in both raw counts and engineering units of kilonewtons. The passive-wavefield data include 28 h of ambient noise recorded over two nighttime deployments. The data set is shown to be useful for active-source and passive-wavefield three-dimensional imaging and other subsurface characterization techniques, which include horizontal-to-vertical spectral ratios (HVSRs), multichannel analysis of surface waves (MASW), and microtremor array measurements (MAM).

Non-iterative reconstruction of interferenceless coded aperture correlation holography enabled high quality three-dimensional imaging

Interferenceless coded aperture correlation holography (I-COACH) is a rapidly developing indirect three-dimensional (3D) imaging technique. However the ideal point spread function of imaging system is not obtained in most cases, the object hologram is usually correlated with the system response of a limited-size pinhole during the reconstruction process. As a result, the quality of reconstructed images is contaminated by noise. In this paper, the system response of a limited-size pinhole is regarded as the convolution of the pinhole (as an object) intensity and the ideal point spread function of I-COACH, a mathematical analysis of the background noise is conducted and a general high-quality reconstruction mathematic model of I-COACH system is derived when a limited-size pinhole is used to record point spread hologram, in which the reconstructions and noise is separated. Then a non-iterative cross-correlation reconstruction algorithm has been developed here to achieve high-quality 3D reconstruction. The proposed method has been implemented on a regular I-COACH system in both transmission as well as reflection illumination modes to demonstrate the imaging ability of our method. The experimental results show that high quality reconstructions can be achieved by our proposal with a single-exposure object hologram.

Artificial intelligence-enabled quantitative phase imaging methods for life sciences.

Quantitative phase imaging, integrated with artificial intelligence, allows for the rapid and label-free investigation of the physiology and pathology of biological systems. This review presents the principles of various two-dimensional and three-dimensional label-free phase imaging techniques that exploit refractive index as an intrinsic optical imaging contrast. In particular, we discuss artificial intelligence-based analysis methodologies for biomedical studies including image enhancement, segmentation of cellular or subcellular structures, classification of types of biological samples and image translation to furnish subcellular and histochemical information from label-free phase images. We also discuss the advantages and challenges of artificial intelligence-enabled quantitative phase imaging analyses, summarize recent notable applications in the life sciences, and cover the potential of this field for basic and industrial research in the life sciences.

Human tumor viruses: induction of three-dimensional alterations in the host genome structure.

Certain viruses called tumor viruses or oncoviruses are capable to change the gene expression pattern of distinct human or animal cell types in tissue culture, resulting in uncontrolled proliferation as well as a change in the social behavior of the infected cells: the oncovirus-transformed, immortalized cells are capable to form malignant neoplasms in suitable animal models. At present, seven human viruses are categorized as causative agents of distinct human malignancies. The genomes of human tumor viruses, typically encode viral oncoproteins and non- translated viral RNAs that affect the gene expression pattern of their target cells or induce genetic and epigenetic alterations contributing to oncogenesis. Recently, the application of chromatin conformation capture technologies and three-dimensional (3D) molecular imaging techniques revealed how the gene products or genomes of certain human tumor viruses interact with and induce alterations in the 3D host genome structure. This Mini Review aims to cover selected aspects of these developments. The papers, discussed briefly, describe how insertion of a novel viral binding site for the 3D genome organizer cellular protein CCCTC-binding factor (CTCF) into the DNA of T cells infected by human T-cell lymphotropic virus type 1 (HTLV-1) may contribute to lymphomagenesis, as well as how integration of high risk human papillomavirus genome into the host cell DNA may facilitate cervical carcinogenesis. Recent results regarding the interactions of cellular genomes with the episomal, chromatinized DNA genomes of oncogenic human herpesvirus, Epstein-Barr virus (EBV) will also be summarized, similarly to available data regarding contacts formed by episomal or integrated hepatitis B virus (HBV) DNA with host chromatin. Finally, a putative mechanism of hepatitis C virus (HCV) induced chromatin alterations will be presented, which may solve the riddle, how a cytoplasmic RNA virus without a viral oncogene could induce malingnant transfrormation of hepatocytes.

Structure-aware guided filtering for a ring artifact correction in synchrotron x-ray microtomography.

Synchrotron-based x-ray microtomography (S-µCT) is a powerful non-invasive three-dimensional (3D) imaging technique used for visualizing the internal structure of objects with micron-scale spatial resolution. However, in practical applications, ring artifacts often occur in S-µCT, which significantly degrades image quality and hinders interpretation. In this study, we propose a ring artifact correction method based on guided image filtering (GIF). The method first extracts structural prior from the input S-µCT images and then uses it as the guidance image to correct the ring artifacts. Finally, GIF with a self-guidance image is employed to further enhance image quality. Extensive comparisons and analyses on simulations and real data experiments demonstrate that the proposed method is capable of effectively correcting ring artifacts, accompanied by low-dose noise suppression and sparse-view artifact reduction. These findings suggest that the proposed method has great potential to promote the wider applications of S-µCT in the future.

Trabecular Bone Microarchitecture Evaluation in an Osteoporosis Mouse Model.

Bone microstructure refers to the arrangement and quality of bone tissue at the microscopic level. Understanding the bone microstructure of the skeleton is crucial for gaining insight into the pathophysiology of osteoporosis and improving its treatment. However, handling bone samples can be complex due to their hard and dense properties. Secondly, specialized software makes image processing and analysis difficult. In this protocol, we present a cost-effective and easy-to-use solution for trabecular bone microstructure analysis. Detailed steps and precautions are provided. Micro-CT is a non-destructive three-dimensional (3D) imaging technique that provides high-resolution images of trabecular bone structure. It allows for the objective and quantitative evaluation of bone quality, which is why it is widely regarded as the gold standard method for bone quality assessment. However, histomorphometry remains indispensable as it offers crucial cellular-level parameters, bridging the gap between two-dimensional (2D) and 3D assessments of bone specimens. As for the histologic techniques, we chose to decalcify the bone tissue and then perform traditional paraffin embedding. In summary, combining these two methods can provide more comprehensive and accurate information on bone microstructure.

3D Ultrasound and MRI in Assessing Resection Margins during Tongue Cancer Surgery: A Research Protocol for a Clinical Diagnostic Accuracy Study.

Surgery is the primary treatment for tongue cancer. The goal is a complete resection of the tumor with an adequate margin of healthy tissue around the tumor.Inadequate margins lead to a high risk of local cancer recurrence and the need for adjuvant therapies. Ex vivo imaging of the resected surgical specimen has been suggested for margin assessment and improved surgical results. Therefore, we have developed a novel three-dimensional (3D) ultrasound imaging technique to improve the assessment of resection margins during surgery. In this research protocol, we describe a study comparing the accuracy of 3D ultrasound, magnetic resonance imaging (MRI), and clinical examination of the surgical specimen to assess the resection margins during cancer surgery. Tumor segmentation and margin measurement will be performed using 3D ultrasound and MRI of the ex vivo specimen. We will determine the accuracy of each method by comparing the margin measurements and the proportion of correctly classified margins (positive, close, and free) obtained by each technique with respect to the gold standard histopathology.

Accuracy of different types of surgical guides for dental implant placement

Abstract
 BACKGROUND: Nowadays, the development of three-dimensional (3D) imaging techniques and implant planning software has contributed to a large diffusion of prosthetically guided implant placement.
 AIM: The aim of this study is to compare virtual planning accuracy of dental implant placement using various surgical templates.
 MATERIALS AND METHODS: The study involved 24 partially and fully edentulous patients. Patients were randomized according to a parallel group design into four arms: Templates for pilot osteotomy made by 3D-printing (group I), full-guide templates made by 3D-printing (group II), surgical templates for pilot osteotomy made by milling (group III) and full-guide templates made by milling (group IV). The accuracy of dental implant position was assessed by comparing the planned and actual position of the implants according to pre- and postoperative computed tomography (CT). Three mean deviation parameters (angular, at the neck position, at the apex position) were defined to evaluate the discrepancy between the planned and placed implant positions.
 RESULTS: The best results were obtained in Group III, where dental implant placement was performed using milled surgical templates for pilot osteotomy, the mean angular deviation, deviation at the neck and deviation at the apex of the implant were 4.013.21⁰, 0.380.23 mm, 0.560.51 mm respectively (p0.001 for all). In the group where milled surgical templates were used for the full guided osteotomy, the mean angular deviation was 5.665.38⁰, deviations at the implant neck and apex were 0.730.71 mm, 0.680.67 mm, respectively (p 0.001 for all), which demonstrates high accuracy of implant placement within the "safety zone".
 In groups I and II, where templates made by 3D printing were used, lower accuracy scores were obtained. In the group for pilot osteotomy, the mean angular deviation was 7.715.94⁰, the mean deviation at the neck was 1.021.07 mm, the mean deviation at the apex of the implant was 1.401.69 mm (p0.001 for all). In the group, for full guided osteotomy, the mean angular deviation, deviations at the neck and at the apex of the implant were 6.46.21⁰, 0.580.45 mm, 0.830.80 mm respectively (p0.001 for all).
 CONCLUSIONS: Dental implant placement with the use of surgical templates makes it possible to achieve a high accuracy of the implant position. Milled surgical templates are more accurate than 3D-printed templates for dental implants, which allows us to introduce surgical templates made by milling into clinical practice in order to improve the quality of dental care.

High precision 3D imaging with timing corrected single photon LiDAR.

Single photon light detection and ranging (LiDAR) is an important technique for high precision long distance three-dimensional (3D) imaging. However, due to the effects and native limitations of system components, there exists ranging errors when using LiDAR system. For the LiDAR system that requires trigger detector to provide synchronization signals, the fluctuation of laser pulse energy causes the change of the initial time of the constant threshold triggered timing module, and subsequently leads to the ranging error. In this paper, we build a dual SPADs LiDAR system to avoid the ranging error caused by the fluctuation of laser pulse energy. By adding a reference optical path, the flight time of signal photons is corrected by reference photons, so as to realize the correction of ranging. A series of experiments demonstrate that the proposed LiDAR system has the capability of high precision ranging and 3D imaging. The system achieves range of error of 0.15 mm and range resolution of 0.3 mm at a distance of 29 m.

Coherent optical two-photon resonance tomographic imaging in three dimensions

Magnetic resonance imaging is a three-dimensional imaging technique, where a gradient of the magnetic field is used to interrogate spin resonances with spatial resolution. The application of this technique to probe the coherence of atoms with good three-dimensional resolution is a challenging application. We propose and demonstrate an optical method to probe spin resonances via a two-photon Raman transition, reconstructing the 3D-structure of an atomic ensemble’s coherence, which is itself subject to external fields. Our method relies on a single time-and-space resolved heterodyne measurement, allowing the reconstruction of a complex 3D coherence profile. Owing to the optical interface, we reach a tomographic image resolution of 14 × 14 × 36 μm3. The technique allows to probe any transparent medium with a resonance structure and provides a robust diagnostic tool for atom-based quantum information protocols. As such, it is a viable technique for application to magnetometry, electrometry, and imaging of electromagnetic fields.

A single camera unit-based three-dimensional surface imaging technique

A single camera unit-based three-dimensional surface imaging technique

Three-dimensional analysis for measuring volumetric changes after a noninvasive treatment performed with a new system delivering microwave energy for unwanted abdominal fat reduction.

A growing demand for aesthetic treatments for localized abdominal unwanted fat has developed as a healthy lifestyle is not always able to improve abdomen appearance. The purpose of this retrospective nonrandomized observational study was to evaluate the efficacy and safety of a new device delivering microwaves energy for unwanted fat reduction, using three-dimensional (3D) imaging analysis. Twenty patients (both female and male) were treated in the abdominal area. Subjects received 4 treatments with the study device. Follow-up evaluations were conducted to estimate safety and efficacy. A Numerical Rating Scale (NRS) was used for pain assessment. Patient's 3D imaging analysis was performed at baseline and at 3 months follow-up. Finally, a satisfaction questionnaire was filled in by all the patients. All subjects completed the whole cycle of treatments and presented for the follow-up visits. Analysis of 3D imaging yielded a significantly reduction in circumference (cm) and volume (cm3 ), passing, respectively, from 85.2 ± 8.1 cm and 1950.6 ± 471.0 cm3 at baseline to 80.8 ± 8.2 cm and 1728.9 ± 490.9 cm3 (p < 0.001) at 3-months follow-up after the last treatment. According to the NRS results, the treatment was well tolerated. From the analysis of the satisfaction questionnaire the 90% of patients are interested in carrying out the same treatment in other body areas. With the use of three-dimensional imaging techniques, the efficacy of a new system delivering microwaves energy for the reduction of abdominal volume correlated to a subdermal fat reduction while preserving/improving skin tightening, was quantitatively and objectively demonstrated.

A three-dimensional method for morphological analysis and flow velocity estimation in microvasculature on-a-chip.

Three-dimensional (3D) imaging techniques (e.g., confocal microscopy) are commonly used to visualize in vitro models, especially microvasculature on-a-chip. Conversely, 3D analysis is not the standard method to extract quantitative information from those models. We developed the μVES algorithm to analyze vascularized in vitro models leveraging 3D data. It computes morphological parameters (geometry, diameter, length, tortuosity, eccentricity) and intravascular flow velocity. μVES application to microfluidic vascularized in vitro models shows that they successfully replicate functional features of the microvasculature in vivo in terms of intravascular fluid flow velocity. However, wall shear stress is lower compared to in vivo references. The morphological analysis also highlights the model's physiological similarities (vessel length and tortuosity) and shortcomings (vessel radius and surface-over-volume ratio). The addition of the third dimension in our analysis produced significant differences in the metrics assessed compared to 2D estimations. It enabled the computation of new indices, such as vessel eccentricity. These μVES capabilities can find application in analyses of different in vitro vascular models, as well as in vivo and ex vivo microvasculature.