Three-dimensional Imaging Research Articles

Microscopic interface deterioration mechanism and damage behavior of high-toughness recycled aggregate concrete based on 4D in-situ CT experiments

High-toughness recycled aggregate concrete (HTRAC), as an innovative green building material, showcases outstanding performance and environmental attributes. To investigate its microscopic structural characteristics and the mechanisms of damage evolution under loading, a series of 4D in-situ X-ray computed tomography (CT) experiments were conducted under uniaxial compression conditions. During the experimental process, detailed scans were performed on six key loading points (0 %, 30 %, 60 %, and 100 % of the peak load, 70 % and 40 % of the post-peak load of the specimen). Advanced three-dimensional image processing techniques were utilized to conduct a comprehensive analysis of internal features within the specimen, including pores, steel fibers, and cracks. The evolution of damage in HTRAC was characterized by both qualitative 2D crack slice analysis and quantitative 3D reconstruction analysis of cracks. Changes in the average grayscale values of CT cross-sectional images were also examined. The deterioration mechanism of recycled aggregate concrete interface cracks was elucidated by the combination of CT images and modeled HTRAC. Furthermore, a statistics model illustrating the interaction mechanism between damage, cracks, and strain was proposed. This study provides technical and theoretical support for the further promotion and application of high-toughness recycled aggregate concrete.

Comparative study on three-dimensional versus two-dimensional imaging using a computer-assisted surgery system for preoperative planning in pediatric middle hepatic tumors

BackgroudThe study objective was to compare three-dimensional and two-dimensional imaging using computer-assisted systems (CASs) in clinical guidance for preoperative surgical planning for middle hepatic tumors in children.MethodsA retrospective analysis was performed on 23 children who underwent surgery for middle hepatic tumors in our hospital from January 2016 to June 2022. The surgical resection plan was formulated by the operator team using two-dimensional CT images before the operation. Then, the same qualified surgeons conducted an in-depth analysis and formulated the surgical resection scheme for the same pediatric patient using three-dimensional imaging of the middle hepatic tumor. The feasibility of the two schemes was compared and analyzed.ResultAll the tumors were successfully removed according to the preoperative method developed using three-dimensional imaging. The postoperative short-term follow-up revealed that all patients were doing well. Preoperative plans were revised in 9 cases after evaluating the three-dimensional images due to the disparity between the original plans and the three-dimensional relationship between the tumor and blood vessels, vascular variation, and the volume of remnant liver.ConclusionsThree-dimensional imaging with a computer-assisted surgery system is superior to two-dimensional imaging in the preoperative planning of pediatric hepatoblastoma.

Effect of Plate Length on Construct Stiffness and Strain in a Synthetic Short-Fragment Fracture Gap Model Stabilized with a 3.5-mm Locking Compression Plate.

To evaluate the effect of 3.5-mm locking compression plate (LCP) length on construct stiffness and plate and bone model strain in a synthetic, short-fragment, fracture-gap model. Six replicates of 6-hole, 8-hole, 10-hole, and 12-hole LCP constructs on a short-fragment, tubular Delrin fracture gap model underwent four-point compression and tension bending. Construct stiffness and surface strain, calculated using three-dimensional digital image correlation, were compared across plate length and region of interest (ROI) on the construct. The 12-hole plates (80% plate-bone ratio) had significantly higher construct stiffness than 6-hole, 8-hole, and 10-hole plates and significantly lower plate strain than 6-hole plates at all ROIs. Strain on the bone model was significantly lower in constructs with 10-hole and 12-hole plates than 6-hole plates under both compression and tension bending. Incremental increases in construct stiffness and incremental decreases in plate strain were only identified when comparing 6-hole, 8-hole, and 10-hole plates to 12-hole plates, and 6-hole to 12-hole plates, respectively. Strain on the bone model showed an incremental decrease when comparing 6-hole to 10-hole and 12-hole plates. A long plate offered biomechanical advantages of increased construct stiffness and reduced plate and bone model strain, over a short plate in this in vitro model.

Self-calibration method for geometric parameters based on feature point projection trajectories in Cone-beam Computed Laminography

Cone-beam computed laminography (CBCL) is an X-ray three-dimensional imaging method that is suitable for large plate-like objects. Geometric parameter calibration is crucial during CL imaging to prevent geometric artifacts in the reconstructed image. This study introduced a self-calibration method employing feature-point projection trajectories for CL geometric parameters. The method constructed point projection trajectory models for the system’s geometric parameters and optimized the best fit of these models to the characteristic point projection trajectories to solve for the geometric parameters of the system. Furthermore, this study examined the impact of the feature point location in the object coordinate system on the parameter calibration accuracy and reduced the required feature point locations from 11°to 4°using the alternating optimization algorithm. The imaging results demonstrated the ability of the method to achieve high-accuracy calibration of CL system geometric parameters, reducing the calibration error of the rotational axis tilt angle α from 1.1% to 0.08% while exhibiting resilience to noise. The proposed method enabled the calibration of all CL system geometric parameters without the model calibration, laying the groundwork for rectifying image geometric artifacts and enhancing CL imaging quality. Moreover, this method presents a novel approach for CT system geometric parameter calibration.

Sacroiliac pain after total hip arthroplasty: a combined analysis of clinical data and three-dimensional imaging in standing and sitting positions.

Patients frequently complain of low back pain and sacroiliac joint pain (SIP) following total hip arthroplasty (THA). We hypothesized that patients with SIP would display different pelvic incidence (PI) values between standing and relaxed sitting positions, indicative of increased motion in the sacroiliac joints. In this retrospective case-control study, 94 patients who underwent unilateral THA and experienced SIP were compared with 94 control patients without SIP. SIP was confirmed through clinical tests and investigated using biplanar imaging in both standing and sitting positions. The key parameters analyzed included PI, sacral slope (SS), lumbar lordosis (LL), and limb length discrepancy (LLD). Patients without SIP showed a mean difference in PI of -1.5° (-8°-5°) between standing-to-sitting positions, whereas those with SIP showed a difference of -3.3° (-12°-0°)(P < 0.0001), indicating more motion in the sacroiliac joint during daily activities in the latter group. Patients with SIP showed smaller change in LL between standing-to-sitting positions (mean:6.3°; range:-8°-27°) compared with those without SIP (mean:9.5°; range:-12°-28°)(P = 0.006). No significant differences were noted in functional leg length between patients with (mean:7mm; range:0-12mm) and without SIP (mean:7mm; range:0-11mm)(P = 0.973). This study revealed significant sacroiliac joint motion in patients with SIP post-THA, as indicated by PI changes, increased posterior pelvic tilt, and reduced change in the LL. Contrary to common belief, SIP did not correlate with LLD.

Second order and transverse flow visualization through three-dimensional particle image velocimetry in millimetric ducts

Despite recent advances in 3D particle image velocimetry (PIV), challenges remain in measuring small-scale 3D flows, in particular flows with large dynamic range. This study presents a scanning 3D-PIV system tailored for oscillatory flows, capable of resolving transverse flows less than a percent of the axial flow amplitude. The system was applied to visualize transverse flows in millimetric straight, toroidal, and twisted ducts. Two PIV analysis techniques, stroboscopic and semi-Lagrangian PIV, enable the quantification of net motion as well as time-resolved axial and transverse velocities. The experimental results closely align with computational fluid dynamics (CFD) simulations performed in a digitized representation of the experimental model. The proposed method allows the examination of periodic flows in systems down to microscopic scale and is particularly well-suited for applications that cannot be scaled up due to their complex, multi-physics nature.

Tomographic examination of the head model through image reconstruction from measurement data

This study aims to integrate ultrasound tomography with numerical algorithms to significantly enhance brain sensing capabilities for diagnosing critical brain abnormalities. Advanced ultrasound tomography, employing a high-frequency transducer array, captures intricate brain structures. The echoes processed by multi-channel receivers allow for three-dimensional imaging. Deep learning models, particularly convolutional neural networks, undergo rigorous training on extensive datasets. Hyperparameter tuning and regularization are key to model optimization. Algorithms handle large datasets, detecting subtle pathological changes in ultrasound images. The system demonstrates proficient image reconstruction and analysis. Implementing deep learning algorithms rectifies operator-dependent inconsistencies and imaging artifacts. The analysis shows significant improvements in diagnostic accuracy and processing time. The convergence of ultrasound tomography and deep learning faces challenges such as image quality variation, computational demands, and clinical integration. Despite these, the enhanced image clarity and the ability to conduct real-time analytics are promising. The study sets a new standard in neurological diagnostics, indicating the potential for sophisticated diagnostic tools to become accessible in diverse healthcare settings.

Experimental study of rock fracture behavior under direct tension using three-dimensional digital image correlation

Understanding the mechanical characteristics of rocks when subjected to direct tension is crucial for assessing the stability of rock formations. Within the scope of this research, a series of tests was conducted using Tage tuff to assess the deformation behavior and crack extension of rock under direct tension. The axial, lateral, and shear strain fields as well as crack propagation, localized deformation behavior, and failure mode of the rocks were analyzed using three-dimensional digital image correlation method. The results showed that the axial strain fields on the specimen surface were heterogeneous, with different locations and localization occurring in the pre-peak stage, which was similar to the evolution of shear strain, whereas the lateral strain only showed slight changes. The crack extension direction was inferred, indicating that both tensile and shear stress occurred in the tests. Furthermore, different stress–strain responses were observed for the inside and outside of the localized bands. Then, the surface patterns of specimen failure were scanned and analyzed to assess the failure mode and residual strength of the specimen under direct tensile stress. Finally, the results of direct tension, uniaxial compression, and Brazilian split tests for Tage tuff were compared, and the complete stress–strain curve of uniaxial tension (UT) was simulated using a nonlinear-variable-compliance constitutive equation. This study provides a deeper understanding into the damage behavior of rocks under direct tension.

A Comprehensive Ultrasound Investigation of Lower Facial and Neck Structure.

The jawline and neck significantly influence facial aesthetics. Botulinum toxin and filler are highly favored as minimally invasive jawline rejuvenation procedures. However, little evidence exists on the age-related skin and superficial fat tissue transformations in healthy individuals to guide targeted interventions. A quantitative sonographic assessment was conducted on 51 patients. Total soft tissue thickness (the skin and superficial fat compartments) was measured at eight sites along the jawline and four sites at the neck. Among them, 21 patients received botulinum toxin A (BTX-A) injections for jawline lift. Three-dimensional images and questionaries were obtained before and after the treatment. In this ultrasound study, total superficial soft tissue thickness decreased significantly from the prejowl sulcus to the lateral cheek, with the jowl showing the greatest thickness. Vertically, significant differences in thickness were noted between superior and inferior points, especially at the inferior prejowl sulcus for the middle-aged and the jowl for the elderly group when comparing across age groups. Soft tissue thickness at the neck decreased from zones 1 to 3, consistent in all age groups. BMI and age positively correlated with soft tissue thickness at the jawline and neck. Regarding BTX-A injections, participants described a pain-free injection process, of which 85.7% reported substantial aesthetic improvement and sharpening of the submental-cervical angle. This study quantified age-related changes in superficial soft tissues at the jawline and neck regions with ultrasound imaging. With aging, soft tissue thickness alters with high region-specificity. Tailoring interventions to the specific alterations within each age group can achieve optimal results with enhanced safety. This study provided a quantitative analysis of skin and superficial fat compartment thicknesses for the young, middle-aged, and elderly groups. This study illustrated how skin and superficial fat compartments change with age in a regionally specific manner for both the jawline and neck regions. This study revealed a positive association between BMI and age with skin and superficial fat tissue thicknesses, especially in areas like the jowl, submental, and neck. This study provided guidance for a safe and effective botulinum toxin. A injection method focusing on the injection depths and regions to achieve optimal jawline rejuvenation outcomes and patient experience. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Three-Dimensional Morphometric Analysis of the Volar Cortical Shape of the Lunate Facet of the Distal Radius.

In cases of distal radius fractures, the fixation of the volar lunate facet fragment is crucial for preventing volar subluxation of the carpal bones. This study aims to clarify the sex differences in the volar morphology of the lunate facet of the distal radius and its relationship with the transverse diameter of the distal radius. Sixty-four CT scans of healthy wrists (30 males and 34 females) were evaluated. Three-dimensional (3D) images of the distal radius were reconstructed from the CT data. We defined reference point 1 as the starting point of the inclination toward the distal volar edge, reference point 2 as the volar edge of the joint on the bone axis, and reference point 3 as the volar edge of the distal radius lunate facet. From the 3D coordinates of reference points 1 to 3, the bone axis distance, volar-dorsal distance, radial-ulnar distance, 3D straight-line distance, and inclination angle were measured. The transverse diameter of the radius was measured, and its correlations with the parameters were evaluated. It was found that in males, compared to females, the transverse diameter of the radius is larger and the protrusion of the volar lunate facet is greater. This suggests that the inclination of the volar surface is steeper in males and that the volar locking plate may not fit properly with the volar cortical bone of the lunate facet, necessitating additional fixation.

To Shrink or Not to Shrink? An Objective Assessment of Free Gracilis Muscle Volume Change in Lower-Extremity Defect Reconstruction.

Background: The use of free gracilis muscle flaps in reconstructive surgery of the lower leg is common practice to cover defects. However, there is still a lack of understanding of the morphometric changes that occur in the transferred muscle and area of interest over time, particularly the characteristic volume decrease that is observed over the course of the first year. This study aimed to assess volume changes in patients with free gracilis muscle flap reconstruction following infection, trauma, or malignancies of the lower extremity. Methods: Three-dimensional surface imaging was performed intraoperatively after 2 weeks, 6 months, and 12 months with the Vectra H2 system. A total of 31 patients were included in this study and analyzed. Results: There was an average volume increase of 146.67 ± 29.66% 2 weeks after reconstruction. Compared to this volume increase, there was a reduction of 108.44 ± 13.62% after 12 months (p < 0.05). Overall, we found a shrinkage to 85.53 ± 20.14% of the intraoperative baseline volume after 12 months. Conclusions: The use of non-invasive 3D surface imaging is a valuable tool for volume monitoring after free flap reconstruction of the lower extremity. The free gracilis muscle flap undergoes different phases of volume change over the first year, with the greatest influence on overall change being the development and decongestion of edema. Precise initial surgical tailoring is crucial for optimal long-term functional and cosmetic results.

Imaging in Autologous Breast Reconstruction.

The evolution of imaging actively shapes clinical management in the field. Ultrasonography (US), computed tomography angiography (CTA), and magnetic resonance angiography (MRA) stand out as the most extensively researched imaging modalities for ABR. Ongoing advancements include "real-time" angiography and three-dimensional (3D) surface imaging, and future prospects incorporate augmented or virtual reality (AR/VR) and artificial intelligence (AI). These technologies may further enhance perioperative efficiency, reduce donor-site morbidity, and improve surgical outcomes in ABR.

Physical characteristics identification of the concrete interfacial transition zone via 3D image scanning

The interfacial transition zone (ITZ) is the weakest link in concrete materials. The physical characteristics of the ITZ, such as its microhardness and thickness, significantly influence the mechanical properties and durability of concrete. Typically, microhardness testing is employed to identify the physical features of the ITZ through line measurements with a certain degree of randomness. In order to accurately describe ITZ physical characteristics, this study proposes a novel physical characteristics identification method via three-dimensional (3D) image scanning. The fundamental principle of this method lies in the varying hardness of each concrete phase, resulting in different surface elevations after polishing. As the polishing abrasiveness changes from coarse (240 mesh) to fine (800 mesh), the ITZ can be clearly observed in the 3D point cloud images of the experimental concrete. The ITZ geometrical information (thickness and different surface heights) can be easily identified using 3D scanned images. It was also found that there was a considerable linear regression relationship between the height difference and the relative microhardness variation; thus, the ITZ microhardness could be indirectly recognized through surface measurements. The physical characteristics of ITZ can be statistically analysed, effectively mitigating the bias inherent in traditional test results and significantly improving identification efficiency and accuracy.

Deep learning-based quantification of brain atrophy using 2D T1-weighted MRI for Alzheimer's disease classification.

Determining brain atrophy is crucial for the diagnosis of neurodegenerative diseases. Despite detailed brain atrophy assessments using three-dimensional (3D) T1-weighted magnetic resonance imaging, their practical utility is limited by cost and time. This study introduces deep learning algorithms for quantifying brain atrophy using a more accessible two-dimensional (2D) T1, aiming to achieve cost-effective differentiation of dementia of the Alzheimer's type (DAT) from cognitively unimpaired (CU), while maintaining or exceeding the performance obtained with T1-3D individuals and to accurately predict AD-specific atrophy similarity and atrophic changes [W-scores and Brain Age Index (BAI)]. Involving 924 participants (478 CU and 446 DAT), our deep learning models were trained on cerebrospinal fluid (CSF) volumes from 2D T1 images and compared with 3D T1 images. The performance of the models in differentiating DAT from CU was assessed using receiver operating characteristic analysis. Pearson's correlation analyses were used to evaluate the relations between 3D T1 and 2D T1 measurements of cortical thickness and CSF volumes, AD-specific atrophy similarity, W-scores, and BAIs. Our deep learning models demonstrated strong correlations between 2D and 3D T1-derived CSF volumes, with correlation coefficients r ranging from 0.805 to 0.971. The algorithms based on 2D T1 accurately distinguished DAT from CU with high accuracy (area under the curve values of 0.873), which were comparable to those of algorithms based on 3D T1. Algorithms based on 2D T1 image-derived CSF volumes showed high correlations in AD-specific atrophy similarity (r = 0.915), W-scores for brain atrophy (0.732 ≤ r ≤ 0.976), and BAIs (r = 0.821) compared with those based on 3D T1 images. Deep learning-based analysis of 2D T1 images is a feasible and accurate alternative for assessing brain atrophy, offering diagnostic precision comparable to that of 3D T1 imaging. This approach offers the advantage of the availability of T1-2D imaging, as well as reduced time and cost, while maintaining diagnostic precision comparable to T1-3D.

Aberration correction in 3D transthoracic echocardiography

Three-dimensional cardiac imaging has been available in the clinic for more than two decades. Continuous improvement in image quality has occurred in this period due to the development of probe technology and beamforming techniques. The purpose of this article is to quantitatively and qualitatively analyze the effect of a commercially available aberration correction algorithm on clinically acquired 3D transthoracic echocardiography (3D TTE) images. Clinical triplane and 3D volume cineloops of at least one cardiac cycle of pre-beamformed channel data were captured from 50 patients using a GE HealthCare Vivid E95 system with the 4Vc-D matrix array probe. This resulted in a total of 3200 vol and 3136 triplane frames. The data were post-processed with and without aberration correction. Quantitatively, assessed by an image quality parameter based on coherence, all recordings were improved by aberration correction compared to those without aberration correction. Triplane data obtained a larger improvement in image quality than volume data. Qualitatively, as demonstrated by case examples, aberration-corrected images appear sharper, have a brighter tissue signal compared to the cavity, and provide better delineation of cardiac structures. 3D rendering of valves can also be significantly improved. In general, aberration correction provides a systematic improvement in clinical cardiac triplane and 3D volume images.

Three-dimensional image encryption based on structured light illumination and an iterative layer-oriented angular-spectrum algorithm

In this paper, a three-dimensional (3D) image encryption method is proposed based on structured light illumination and an iterative layer-oriented angular-spectrum algorithm, where the original 3D plaintext image is encrypted into a phase-only hologram ciphertext (POHC). The structured light is generated by using a structured phase mask (SPM), and the optical parameters in the SPM all serve as the supplementary keys for increasing the types and quantities of security keys, expanding the key space and enhancing the level of security. Moreover, the introduction of structured light also enhances the invisibility of the ciphertext and concealment of the valid information, overcoming an inherent silhouette problem of the POHC calculated by a traditional layer-oriented angular-spectrum algorithm, and the iterative calculation also suppresses the speckle noise of the decrypted 3D image, improving the decryption quality. Numerical simulations are performed to demonstrate the feasibility of the proposed 3D image encryption method, and the simulation results show that the proposed method exhibits a high feasibility and security, as well as strong robustness.

Fourier Raman light field microscopy based on surface-enhanced Raman scattering.

Raman scattering, as a vibrational spectrum that carries material information, has no photobleaching that enables long-duration imaging. Raman spectra have very narrow emission peaks, and multiplex Raman imaging can be achieved by using different Raman scattering peak signals. These advantages make Raman imaging widely used in biology, cytology, and medicine, which has a wider range of application scenarios. However, obtaining a three-dimensional (3D) Raman image requires scanning for tens of minutes to several hours at present. Therefore, a fast non-scanning 3D Raman imaging method is greatly needed. In this article, we propose a Fourier Raman light field microscopy based on surface-enhanced Raman scattering (sers-FRLFM). Using flower-like gap-enhanced Raman nanoparticles (F-GERNs) to enhance Raman scattering signals, a Fourier-configured light field microscope (LFM) is capable of recording complete four-dimensional Raman field information in a single frame, facilitating the 3D reconstruction of the Raman image without generating reconstruction artifacts at the native object plan. Moreover, F-GERNs can mark specific locations and have the potential to become a new tracing method to achieve specific imaging. This imaging method has great potential in the 3D real-time Raman imaging of cells, microorganisms, and tissues with the lateral resolution of 2.40 µm and an axial resolution of 4.02 µm.

Label-free spatiotemporal decoding of single-cell fate via acoustic driven 3D tomography

Label-free three-dimensional imaging plays a crucial role in unraveling the complexities of cellular functions and interactions in biomedical research. Conventional single-cell optical tomography techniques offer affordability and the convenience of bypassing laborious cell labelling protocols. However, these methods are encumbered by restricted illumination scanning ranges on abaxial plane, resulting in the loss of intricate cellular imaging details. The ability to fully control cellular rotation across all angles has emerged as an optimal solution for capturing comprehensive structural details of cells. Here, we introduce a label-free, cost-effective, and readily fabricated contactless acoustic-induced vibration system, specifically designed to enable multi-degree-of-freedom rotation of cells, ultimately attaining stable in-situ rotation. Furthermore, by integrating this system with advanced deep learning technologies, we perform 3D reconstruction and morphological analysis on diverse cell types, thus validating groups of high-precision cell identification. Notably, long-term observation of cells reveals distinct features associated with drug-induced apoptosis in both cancerous and normal cells populations. This methodology, based on deep learning-enabled cell 3D reconstruction, charts a novel trajectory for groups of real-time cellular visualization, offering promising advancements in the realms of drug screening and post-single-cell analysis, thereby addressing potential clinical requisites.

Generative deep-learning-embedded asynchronous structured light for three-dimensional imaging

Generative deep-learning-embedded asynchronous structured light for three-dimensional imaging

Augmented Reality for Supporting Student’s Engagement in Mathematics Education: A Systematic Literature Review

Augmented reality (AR) has gained considerable attention in academic research as a primary instructional tool to enhance learning across various educational levels, including mathematics education. AR enables the overlaying of three-dimensional images onto real-world environments within an academic setting. While AR has demonstrated its potential to improve learning outcomes in academic contexts, there is a need for a comprehensive review to identify, assess, and summarize empirical findings related to student engagement, particularly in mathematics education. Consequently, a systematic review was conducted to examine the uses of AR in student engagement in mathematics education. A thorough electronic search was performed on the Scopus database to retrieve pertinent journal articles. After applying inclusion and exclusion criteria, 18 studies were selected for analysis. The results reveal that AR can facilitate student engagement in three key aspects: interactive, collaborative, and immersive experiences. Although AR offers several advantages for promoting student engagement in mathematics education, its practical implementation in educational settings requires careful consideration of AR application and content design and close collaboration between educators and technology. Furthermore, the successful integration of AR technology relies on the well-planned implementation of learning programs that effectively incorporate AR elements for mathematics education.