Three-dimensional Imaging Technology Research Articles

Monocular Metasurface for Structured Light Generation and 3D Imaging with a Large Field-of-View.

Structured light three-dimensional (3D) imaging technology captures the geometric information on 3D objects by recording waves reflected from the objects' surface. The projection angle and point number of the laser dots directly determine the field-of-view (FOV) and the resolution of the reconstructed image. Conventionally, diffractive optical elements with micrometer-scale pixel size have been used to generate laser dot arrays, leading to limited FOV and point number within the projection optical path. Here, we theoretically put forward and experimentally demonstrate a monocular geometric phase metasurface composed of deep subwavelength meta-atoms to generate a 10 798 dot array within an FOV of 163°. Attributed to the vast number and high-density point cloud generated by the metasurface, the 3D reconstructed results showcase a maximum relative error in depth of 5.3 mm and a reconstruction error of 6.07%. Additionally, we propose a spin-multiplexed metasurface design method capable of doubling the number of lattice points. We demonstrate its application in the field of 3D imaging through experiments, where the 3D reconstructed results show a maximum relative depth error of 0.44 cm and a reconstruction error of 2.78%. Our proposed metasurface featuring advanced point cloud generation holds substantial potential for various applications such as facial recognition, autonomous driving, virtual reality, and beyond.

Accuracy and Precision of Three-Dimensionally Printed Orthognathic Surgical Splints

The adoption of three-dimensional (3D) imaging technologies in orthognathic surgery led to the development of virtual surgical planning and printing of patient-specific orthognathic surgical splints (OSSs). The accuracy and precision of 3D printed OSSs are considered important; however, there is limited data in the literature regarding whether the type of resin materials may influence these measures. A virtual OSS was created using a set of typodont models and printed in Biomed Clear, Dental LT V2, and Surgical Guide resins (Formlabs, Somerville, MA, USA), using a stereolithography printer. The upper intercanine width, intermolar width, and arch length were analysed. Differences between the reference dimensions of the virtual splint and the corresponding mean measurements of the 3D-printed splints were mostly considered clinically acceptable. The greatest variation was observed in the arch length for all 3 materials, which relates to the Z-axis of the printer; only 33.3–66.7% of OSSs were within the tolerance limit of ±0.1 mm quoted by the manufacturer. The Surgical Guide group demonstrated the highest degree of accuracy and precision overall. Further research would help to assess the 3D accuracy and precision, explore the variation found between different resin materials used, and confirm the findings of this research.

Evaluation of the effect of chin prosthesis implantation on mentalis muscles based on three-dimensional imaging technology

BackgroundChin prosthesis implantation, a cosmetic procedure to correct chin asymmetry, depression, or retraction, is generally safe and simple. However, its long-term effects on surrounding tissues are a concern. This study aims to use three-dimensional (3D) scanning to classify mentalis muscle shapes and assess the impact of prosthesis implantation on these muscles. MethodThis study evaluated 450 eligible female participants. Using three-dimensional imaging, data on the types, thickness, width, and length of the left and right mentalis muscles were collected and summarized. The impact of chin prosthesis on these muscle dimensions was assessed using analysis of variance (ANOVA), and the effect on muscle type was determined using the chi-square test. ResultsThe findings show that chin implant placement affects the mentalis muscles, resulting in increased length, thickness, and width. Analysis categorized the subjects' mentalis muscles into three types, further divided into seven subtypes. Chi-square test results indicate that implantation influences the classification of these muscles. ConclusionRecognizing how implant placement affects the mentalis muscle can guide the development of treatments to mitigate these changes. Additionally, understanding the muscle's morphology enables more precise treatment approaches for patients.

Comprehensive Review of Camera Calibration Methods for Three-dimensional Imaging Technology

Comprehensive Review of Camera Calibration Methods for Three-dimensional Imaging Technology

Patient perceptions of three-dimensional (3D) surface imaging technology and traditional methods used to assess anthropometry

BackgroundObesity and overweight are commonplace, yet attrition rates in weight management clinics are high. Traditional methods of body measurement may be a deterrent due to invasive and time-consuming measurements and negative experiences of how data are presented back to individuals. Emerging new technologies, such as three-dimensional (3D) surface imaging technology, might provide a suitable alternative. This study aimed to understand acceptability of traditional and 3D surface imaging-based body measures, and whether perceptions differ between population groups. MethodsThis study used a questionnaire to explore body image, body measurement and shape, followed by a qualitative semi-structured interview and first-hand experience of traditional and 3D surface imaging-based body measures. Results49 participants responded to the questionnaire and 26 participants attended for the body measurements and interview over a 2-month period. There were 3 main themes from the qualitative data 1) Use of technology, 2) Participant experience, expectations and perceptions and 3) Perceived benefits and uses. ConclusionFrom this study, 3D-surface imaging appeared to be acceptable to patients as a method for anthropometric measurements, which may reduce anxiety and improve attrition rates in some populations. Further work is required to understand the scalability, and the role and implications of these technologies in weight management practice. (University Research Ethics Committee reference number ER41719941).

High crosstalk suppression in InGaAs/InP single-photon avalanche diode arrays by carrier extraction structure

Crosstalk has become an urgent issue for single-photon avalanche diode arrays. In previous work, trenches were introduced between pixels to block the crosstalk optical path in planar InGaAs/InP single-photon avalanche diode arrays, since the optical crosstalk was considered as the main crosstalk mechanism. However, the crosstalk suppression effect of this solution is not satisfactory. Here, we demonstrate a carrier extraction structure to efficiently reduce crosstalk by electrically guiding photogenerated crosstalk holes in the non-pixel region to the surface, since we find that the optical-electrical crosstalk is the dominant crosstalk mechanism. Experimental measurements show that a narrow carrier extraction structure makes a 91.52% (96.22%) crosstalk reduction between the nearest neighbor pixels in arrays with 100 (50) μm pixel pitch, and it does not cause any etching damage. These results reveal the primary source of crosstalk in InGaAs/InP single-photon avalanche diode arrays and provide a practical route to fabricate low-crosstalk, high-pixel-density arrays for use in high-resolution three-dimensional imaging and quantum technologies.

Differential Diagnostic Value of Two-dimensional Ultrasound Combined with Three-dimensional Ultrasound Imaging Technology for Cesarean Scar Pregnancy.

Cesarean scar pregnancy (CSP) refers to the phenomenon in which a fertilized egg implants and develops in the scar of the uterus in a woman with a history of cesarean section. The study aimed to explore the differential diagnostic value of two-dimensional ultrasound (2D US) combined with three-dimensional ultrasound (3D US) for CSP. Clinical data of 89 patients with CSP admitted to our hospital from January 2022 to January 2023 were retrospectively analyzed. Of them, 65 patients met the inclusion criteria. Patients underwent 2D US, 3D US, and combined 2D and 3D US imaging. Using the clinical pathological diagnosis as the "gold standard", the differential diagnostic value of 2D US, 3D US, and 2D US combined with 3D US for CSP was compared. The detection rate of CSP using a combined 2D US and 3D US was 98.46%, which was higher than 84.62% and 89.23% achieved with 2D US and 3D US alone, respectively (P<0.05). The pathological results showed that among 65 patients, CSP type I accounted for 24.62%, type II accounted for 55.38%, and type III accounted for 20.00%. The coincidence rate of 2D US combined with 3D US was 98.46%, which was higher than that of 2D US (83.08%) and 3D US 89.23%) alone (P<0.05). The accuracy, specificity, and sensitivity of 2D US combined with 3D US in diagnosing CSP were higher compared to the two methods alone (P<0.05). The combination of 2D US and 3D US can accurately detect and classify CSP, further improving diagnostic efficiency.

Differential diagnostic value of 3.0T MR 3D-ASL technique for recurrence and pseudo-progression of high-grade glioma.

This study aimed to explore the value of 3.0T magnetic resonance three-dimensional arterial spin labeling imaging (3D-ASL) technology in the differential diagnosis of recurrence and pseudo-progression of high-grade gliomas. Fifty patients with high-grade glioma were selected as research objects. All 50 patients were examined by magnetic resonance imaging (MRI), and the lesions were found to be enlarged or abnormally enhanced. All the patients were examined using the 3.0T MR 3D-ASL technique. With targeted biopsy pathology as the gold standard, the diagnostic results of the 3.0T MR 3D-ASL technique were analyzed, and the cerebral blood flow (rCBFmax) ratio was compared between patients with recurrent glioma and patients with pseudo-progression [maximum blood flow value/contralateral mirror area (CBFmax/contralateral mirror area), CBFmax/contralateral white matter, CBFmax/contralateral gray matter]. Among 50 glioma patients, 31 (62.00%) were diagnosed with recurrence through pathological examination, and 19 (38.00%) were diagnosed with pseudo-progression. 30 patients with recurrence (60.00%) and 20 patients with pseudo-progression (40.00%) were diagnosed using 3.0T magnetic resonance 3D-ASL technology. The diagnostic accuracy of 3.0T magnetic resonance 3D-ASL technology was 96.77% (30/31) (p > 0.05). Using pathological results as the "gold standard", the relevant parameters of 3.0T magnetic resonance 3D-ASL technology under different pathological results were analyzed. The results showed that the CBFmax/contralateral mirror area, CBFmax/contralateral white matter, and CBFmax/contralateral gray matter ratios of advanced glioma recurrence patients were significantly higher than those of pseudo-progression (p < 0.05). The application of 3.0T MR 3D-ASL in high-grade glioma can effectively distinguish recurrence and pseudo-progression, with significant diagnostic value.

Modern tools in congenital heart disease imaging and procedure planning: a European survey.

Congenital heart diseases (CHDs) often show a complex 3D anatomy that must be well understood to assess the pathophysiological consequences and to guide therapy. Three-dimensional imaging technologies have the potential to enhance the physician's comprehension of such spatially complex anatomies. Unfortunately, due to the new introduction in clinical practice, there is no evidence on the current applications. We conducted a survey to examine how 3D technologies are currently used among CHD European centres. Data were collected using an online self-administered survey via SurveyMonkey. The questionnaire was sent via e-mail and the responses were collected between January and June 2022. Ninety-eight centres correctly completed the survey. Of these, 22 regularly perform 3D rotational angiography, 43 have the availability to print in-silico models, and 22 have the possibility to visualize holographic imaging/virtual reality. The costs were mostly covered by the hospital or the department of financial resources. From our survey, it emerges that these technologies are quite spread across Europe, despite not being part of a routine practice. In addition, there are still not enough data supporting the improvement of clinical management for CHD patients. For this reason, further studies are needed to develop clinical recommendations for the use of 3D imaging technologies in medical practice.

YENİ NESİL DENTAL YAŞ TAYİNİ YÖNTEMLERİNE GÜNCEL BİR BAKIŞ: BİR DERLEME

In forensic odontology, dental findings play a significant role in determining age and gender. Due to their anatomical structures and durability, teeth have a critical function in identification, even when exposed to mechanical, chemical, and physical effects. However, most of the estimated dental age determination methods are generally invasive, costly, and require procedures like tooth extraction. Additionally, misinterpretations can occur in 2-dimensional imaging due to distortions and magnifications. Recently, three-dimensional imaging technologies, especially Cone Beam Computed Tomography (CBCT), Computed Tomography (CT), and micro-CT, are being used to investigate the potential relationship between the volumetric data of the tooth and pulp and age. CBCT allows researchers to comprehensively evaluate pulp changes and explain the relationship between chronological age and pulp volume. With the 3D images obtained by CBCT, the volumetric measurements of the tooth and pulp can be objectively evaluated and can be used as a criterion for estimated dental age. This review aims to identify, investigate, and summarize the most reliable, practical, and accurate methods for age estimation based on current data and methods.

Reference Range of CT Value in NC-CBBCT Based on Female Breast Structure.

As a new high-resolution three-dimensional CT imaging technology, the essential reference range of CT values in Cone-beam breast computed tomography (CBBCT) has not been established to date. To determine the reference range of computed tomography (CT) values in CBBCT for clinical breast examination. In total, 913 cases (1167 lateral) were subject to CBBCT. CT values of the glandular tissue, fat and different quadrants and different distances of CBBCT images were analyzed. The nipple and muscle were also evaluated. A total of 672 lateral breasts were included in the normal group for investigation. The reference range of the absolute CT value of the chest wall muscle is -136.68~43.36 HU. The reference range of the absolute CT value of the nipple is 176.39~334.02 HU. The reference range of the absolute CT value of fat is -190.4~-63.67HU, and of glandular tissue is -12.2~199.07HU. Our results firstly established the baseline CT values of Non-contrast CBBCT in female breasts, which will benefit cancer screening and lesion locating. The closer the normal breast fat and glandular tissue is to the nipple, the greater the CT value. The older the age, the lower the density. The CT values of fat are unstable in a distance of less than 5 cm, and the CT values of glandular tissues are relatively stable. The difference between the upper and lower quadrants is significant in the same lateral breast and the same section.

Review of Three-Dimensional Handheld Photoacoustic and Ultrasound Imaging Systems and Their Applications.

Photoacoustic (PA) imaging is a non-invasive biomedical imaging technique that combines the benefits of optics and acoustics to provide high-resolution structural and functional information. This review highlights the emergence of three-dimensional handheld PA imaging systems as a promising approach for various biomedical applications. These systems are classified into four techniques: direct imaging with 2D ultrasound (US) arrays, mechanical-scanning-based imaging with 1D US arrays, mirror-scanning-based imaging, and freehand-scanning-based imaging. A comprehensive overview of recent research in each imaging technique is provided, and potential solutions for system limitations are discussed. This review will serve as a valuable resource for researchers and practitioners interested in advancements and opportunities in three-dimensional handheld PA imaging technology.

NOVEL ULTRASOUND TECHNOLOGIES IN ASSESSING THE STATE OF THE MOTHER–PLACENTA–FETUS SYSTEM

The leading process in early pregnancy is forming the mother–placenta–fetus system. The central link of the mother–placenta–fetus system is the placenta. The structural features of the placenta reflect complex relationship between the mother's body and the fetus. Disorder in forming and functioning of the placenta underlies the development of complications such as early termination of pregnancy, placental insufficiency, fetal growth retardation syndrome, preeclampsia, premature birth. In this regard, an integrated approach in studying the hemodynamic system of mother–placenta–fetus is of particular importance. Ultrasound examination remains one of the most promising diagnostic methods. The aim of the study is to increase the effectiveness of diagnosis and prediction of gestational complications associated with violation of hemodynamic parameters in the mother–placenta–fetus system. Materials and methods. The study included 40 patients between the 30th and 32nd weeks of pregnancy with a singleton spontaneous pregnancy: 20 patients with normal course of pregnancy and 20 patients with a diagnosis of placental insufficiency. Ultrasound examination included standard echography in B-mode, color Doppler mapping and the use of modern techniques – three-dimensional imaging technology and innovative techniques of high-precision microvascular imaging SMI (Superb Micro-Vascular Imaging). Results and discussion. In patients with normal pregnancy, a variant of a three-dimensional model of the vascular network with a complex massive vascular network prevailed, whereas in the group with placental insufficiency, a three-dimensional vascular model looked simple: several intertwined vessels. Visual assessment of the placental vascular tree using SMI technology revealed the absence of a clear vascular pattern in the area of interest in patients with placental insufficiency, whereas active placental blood flow was determined in patients with normal pregnancy. Conclusions. The use of modern ultrasound technologies enables to obtain information about the state of placental blood flow, which gives the opportunity to diagnose the development of placental insufficiency in a timely manner.

A History of Innovation: Tracing the Evolution of Imaging Modalities for the Preoperative Planning of Microsurgical Breast Reconstruction.

Breast reconstruction is an essential component in the multidisciplinary management of breast cancer patients. Over the years, preoperative planning has played a pivotal role in assisting surgeons in planning operative decisions prior to the day of surgery. The evolution of preoperative planning can be traced back to the introduction of modalities such as ultrasound and colour duplex ultrasonography, enabling surgeons to evaluate the donor site's vasculature and thereby plan operations more accurately. However, the limitations of these techniques paved the way for the implementation of modern three-dimensional imaging technologies. With the advancements in 3D imaging, including computed tomography and magnetic resonance imaging, surgeons gained the ability to obtain detailed anatomical information. Moreover, numerous adjuncts have been developed to aid in the planning process. The integration of 3D-printing technologies has made significant contributions, enabling surgeons to create complex haptic models of the underlying anatomy. Direct infrared thermography provides a non-invasive, visual assessment of abdominal wall vascular physiology. Additionally, augmented reality technologies are poised to reshape surgical planning by providing an immersive and interactive environment for surgeons to visualize and manipulate 3D reconstructions. Still, the future of preoperative planning in breast reconstruction holds immense promise. Most recently, artificial intelligence algorithms, utilising machine learning and deep learning techniques, have the potential to automate and enhance preoperative planning processes. This review provides a comprehensive assessment of the history of innovation in preoperative planning for breast reconstruction, while also outlining key future directions, and the impact of artificial intelligence in this field.

Single exposure passive three-dimensional information reconstruction based on an ordinary imaging system

Existing three-dimensional (3D) imaging technologies have issues such as requiring active illumination, multiple exposures, or coding modulation. We propose a passive single 3D imaging method based on an ordinary imaging system. Using the point spread function of the imaging system to realize the non-coding measurement on the target, the full-focus images and depth information of the 3D target can be extracted from a single two-dimensional (2D) image through the compressed sensing algorithm. Simulation and experiments show that this approach can complete passive 3D imaging based on an ordinary imaging system without any coding operations. This method can achieve millimeter-level vertical resolution under single exposure conditions and has the potential for real-time dynamic 3D imaging. It improves the efficiency of 3D information detection, reduces the complexity of the imaging system, and may be of considerable value to the field of computer vision and other related applications.

Monocular polarized three-dimensional absolute depth reconstruction technology for multi-target scenes.

The traditional polarization three-dimensional (3D) imaging technology has limited applications in the field of vision because it can only obtain the relative depth information of the target. Based on the principle of polarization stereo vision, this study combines camera calibration with a monocular ranging model to achieve high-precision recovery of the target's absolute depth information in multi-target scenes. Meanwhile, an adaptive camera intrinsic matrix prediction method is proposed to overcome changes in the camera intrinsic matrix caused by focusing on fuzzy targets outside the depth of field in multi-target scenes, thereby realizing monocular polarized 3D absolute depth reconstruction under dynamic focusing of targets at different depths. Experimental results indicate that the recovery error of monocular polarized 3D absolute depth information for the clear target is less than 10%, and the detail error is only 0.19mm. Also, the precision of absolute depth reconstruction remains above 90% after dynamic focusing on the blurred target. The proposed monocular polarized 3D absolute depth reconstruction technology for multi-target scenes can broaden application scenarios of the polarization 3D imaging technology in the field of vision.

Three-dimensional Optical Coherence Thermometry Using Polymeric Nanogels.

In nanothermometry, the use of nanoparticles as thermal probes enables remote and minimally invasive sensing. In the biomedical context, nanothermometry has emerged as a powerful tool where traditional approaches, like infrared thermal sensing and contact thermometers, fall short. Despite the strides of this technology in preclinical settings, nanothermometry is not mature enough to be translated to the bedside. This is due to two major hurdles: the inability to perform three-dimensional thermal imaging and the requirement for tools that are readily available in the clinics. This work simultaneously overcomes both limitations proposing the technology of optical coherence thermometry (OCTh). This is achieved by combining thermoresponsive polymeric nanogels and optical coherence tomography (OCT) - a three-dimensional imaging technology routinely used in clinical practice. The volume phase transition of the thermoresponsive nanogels causes marked changes in their refractive index, making them temperature-sensitive OCT contrast agents. The ability of OCTh to provide three-dimensional thermal images was demonstrated in tissue phantoms subjected to photothermal processes, and its reliability was corroborated comparing experimental results with numerical simulations. The results included in this work set credible foundations for the implementation of nanothermometry in the form of OCTh in the clinical practice. This article is protected by copyright. All rights reserved.

Three-dimensional imaging by compressed sensing based dual-frequency laser phase ranging

Scanless three-dimensional (3D) imaging technology has received extensive attention in recent years due to its rapid detection and system reliability. Compressed sensing imaging technology provides a new solution for the realization of scan-free 3D imaging. In this paper, a 3D imaging method based on dual-frequency laser phase ranging based on compressed sensing technology is introduced and realized. Using the combination of dual-frequency laser phase ranging and compressed sensing theory, two-dimensional range reconstruction from the time-domain light intensity signal collected by a single-point detector is performed. Aiming at the spatial sparsity of the target scene, this technology uses the compressed sensing algorithm to solve the phase information of the two-dimensional spatial distribution contained in the time domain signal so as to invert the 3D image information of the target scene and realize the effect of scanning-free 3D imaging. First, the feasibility of the system is verified by simulations, and the imaging effects of different reconstruction algorithms on different terrains are compared. Second, a non-scanning 3D imaging experimental platform is designed and built. Finally, the 3D images of multiple objects with 32 × 32 resolution are successfully reconstructed through experiments with a compression ratio of 0.25. The ranging accuracy of this system is 0.05 m. This work is promising for applications in multiple objects’ fast detections.

Novel discovery of a lymphatic bridge connecting Schlemm's canal to limbal and conjunctival lymphatic pathway

PurposeSchlemm's canal (SC) is a critical structure regulating aqueous humor (AH) drainage and intraocular pressure (IOP). It is known that in the conventional outflow pathway, AH flows from SC to episcleral veins. We recently reported a high-resolution three-dimensional (3D) imaging technology for intact eyeballs, SC and ocular surface. Using this advanced technology, we herein report the discovery of a new structure, termed lymphatic bridge, that directly connects SC to the limbal and conjunctival lymphatic pathway. Further investigation on this novel outflow pathway may provide new mechanisms and therapeutic approaches for glaucoma. MethodsAs reported previously, intact eyeballs were harvested from Prox-1-GFP (green fluorescent protein) mice and processed by a tissue clearing technique with CLARITY. Samples were immunolabeled with specific antibodies for CD31 (pan-endothelial marker) and LYVE-1 (lymphatic vessel endothelial hyaluronan receptor-1) and imaged by light-sheet fluorescent microscopy. The limbal areas were examined to locate connecting channels between SC and limbal and conjunctival lymphatic vessels. Moreover, in vivo anterior chamber dye injection was performed with Texas Red dextran for functional analysis on AH outflow. ResultsA novel lymphatic bridge structure that expressed both Prox-1 and LYVE-1 was discovered between the SC and limbal lymphatic vessels connected with conjunctival lymphatic pathway. Results from the anterior chamber dye injection also confirmed AH drainage into the conjunctival lymphatic outflow pathway. ConclusionsThis study provides the first evidence on the direct connection between SC and conjunctival lymphatic pathway. This new pathway is distinctive from the traditional episcleral vein pathway and merits further investigation.

A high temporal-spatial resolution three-dimensional imaging method using arrayed-focus structured illumination with differential axial enhancement

High precision and fast three-dimensional (3D) microscopic imaging technology plays an extremely important role in MEMS, micro optics, microelectronics, biomedicine and other fields. In this paper, a confocal microscopic 3D imaging method based on differential array focusing structured light illumination (DAF-SIM) is proposed. Theoretical analysis and experimental results show that under the 100x/NA 0.95 objective lens, the lateral resolution of this method reaches 173 nm, exceeding the optical diffraction limit, the axial sensitivity is better than 10 nm, and the time resolution is about 3 Hz@2.3 M Pixel, achieving the goal of high horizontal and axial resolution and time resolution. The high spatial and temporal resolution of DAF-SIM 3D micro imaging method provides a highly applicable, efficient and high-precision online micro terrain detection scheme for intelligent manufacturing and other fields.