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Spiral array transducers with a sparse 2-D aperture have demonstrated their potential in realizing 3-D ultrasound imaging with reduced data rates. Nevertheless, their feasibility in high-volume-rate imaging based on unfocused transmissions has yet to be established. From a metrology standpoint, it is essential to characterize the acoustic field of unfocused transmissions from spiral arrays not only to assess their safety but also to identify the root cause of imaging irregularities due to the array's sparse aperture. Here, we present a field profile analysis of unfocused transmissions from a density-tapered spiral array transducer (256 hexagonal elements, 220- [Formula: see text] element diameter, and 1-cm aperture diameter) through both simulations and hydrophone measurements. We investigated plane- and diverging-wave transmissions (five-cycle, 7.5-MHz pulses) from 0° to 10° steering for their beam intensity characteristics and wavefront arrival time profiles. Unfocused firings were also tested for B-mode imaging performance (ten compounded angles, -5° to 5° span). The array was found to produce unfocused transmissions with a peak negative pressure of 93.9 kPa at 2 cm depth. All transmissions steered up to 5° were free of secondary lobes within 12 dB of the main beam peak intensity. All wavefront arrival time profiles were found to closely match the expected profiles with maximum root-mean-squared errors of [Formula: see text] for plane wave (PW) and [Formula: see text] for diverging wave. The B-mode images showed good spatial resolution with a penetration depth of 22 mm in PW imaging. Overall, these results demonstrate that the density-tapered spiral array can facilitate unfocused transmissions below regulatory limits (mechanical index: 0.034; spatial-peak, pulse-average intensity: 0.298 W/cm2) and with suppressed secondary lobes while maintaining smooth wavefronts.

This article presents a structured light codification technique called frequency shift method which is especially designed for scenes containing strong interreflections. The method works by projecting multiple sine wave patterns having different frequencies. While the phase shift method associates a phase to each column of the projector, in the proposed codification, each column of the projector is uniquely encoded by the frequencies used and explicitly decoded using the discrete Fourier transform. This encoding allows the method to recover all the projector columns that contribute to a camera pixel’s observed intensity. An energy minimization is then used to separate direct and indirect illuminations. Objects presenting diffuse and specular interreflections are considered, and our experimental results illustrate the efficiency of our method compared with previously proposed methods.

We investigated the role of three-dimensional (3-D) CT in the diagnosis and management of four bipartite scaphoids in three patients. We computed the volume ratio, moment of inertia ratio and direction vector from the centroid of the scaphoid to the os centrale carpi. We found that the os centrale carpi was always smaller than the scaphoid and showed an elongated shape in the scaphoid longitudinal axis. Its position was always posterior compared with the scaphoid anteroposterior axis. The main morphological feature of bipartite scaphoids was the continuity of the scaphoid from its proximal to distal aspect along the longitudinal axis. These criteria from 3-D imaging should be considered useful in the diagnosis of bipartite scaphoid as it allows differentiation from nonunion. 3-D single-photon emission computed tomography (SPECT)/CT was helpful in the surgical decision-making when the patient was symptomatic. 3-D imaging was also used for the preoperative simulation and planning of bone fusion as it simplifies surgery and makes it more accurate. Here we provide clear criteria for diagnosing bipartite scaphoids and for the planning when surgery is deemed necessary.

Objectives: Digital nerve lesions result in a loss of sensation at the radial or ulnar aspect of the respective digit. Available tools to monitor the recovery of tactile acuity have been criticized for their lack of validity. Three-dimensional (3-D) imaging of the anesthetic area (AA) could serve as [for full text, please go to the a.m. URL]

OBJECTIVE: The aim of this study was to propose and validate a three-dimensional (3D) methodology for the assessment of canine eruption in patients born with unilateral cleft lip and palate (UCLP) following secondary alveolar bone graft (SABG). METHODS AND MATERIALS: A total of 10 patients (four females, six males; mean age: 8.8 years) with UCLP who underwent SABG were recruited. Pre- and 6-month post-operative cone-beam computed tomography (CBCT) was acquired for all patients. Post-operative data was registered onto pre-operative data utilizing voxel-based registration. Following superimposition, a segmentation process was applied to segment maxillary canine on both cleft and non-cleft side. Thereafter, translational and rotational changes in canine position were assessed for both cleft and non-cleft side by two observers. RESULTS: The intra-class correlation coefficient (ICC) indicated excellent reliability (≥0.90) with inter and intra-observer error of less than 0.05 mm. The overall ICC was found to be high for assessing both translational and rotational changes. The mean absolute inter- and intra-observer difference for translational and rotational changes was found to be less than 1 mm and 3°. CONCLUSION: The present method was found to be reliable proving to be clinically applicable for assessing maxillary canine eruption changes in both cleft and non-cleft bone. ispartof: CLINICAL AND EXPERIMENTAL DENTAL RESEARCH vol:7 issue:3 pages:285-292 ispartof: location:United States status: published

The aim: to evaluate combined microscopy techniques for determining the morphological and optical properties of methadone hydrochloride (MDN) crystals. Materials and methods: MDN crystal formation was optimized using a closed container method and crystals were characterized using polarized light microscope (PLM), scanning electron microscopy (SEM) and confocal microscopy (CM). SEM and CM were used to determine MDN crystal thickness and study its relationship with crystal retardation colours using the Michel-Levy Birefringence approach. Results: Dimensions (mean±SD) of diamond shaped MDN crystals were confirmed using SEM and CM. Crystals were 46.4±15.2 Vs 32.0±8.3 µm long, 28.03±8.2 Vs 20.85±5.5 µm wide, and 6.62±2.9 Vs 9.6±4.6 µm thick, respectively. There were significant differences between SEM and CM thickness measurements (U=1283, p, Мета: Оцінити комбіновані методи мікроскопії для визначення морфологічних та оптичних властивостей кристалів метадону гідрохлориду (МДН). Матеріали та методи. Формування кристалів МДН було оптимізовано за допомогою методу закритого контейнера, а кристали охарактеризовані за допомогою поляризованого світлового мікроскопа (PLM), скануючої електронної мікроскопії (SEM) та конфокальної мікроскопії (CM). SEM та CM були використані для визначення товщини кристала МДН та вивчення його зв’язку з кольорами сповільнення кристалів з використанням підходу з двозаломленням Мішеля-Леві. Результати: Розміри (середнє±SD) кристалів МДН у формі ромба були підтверджені за допомогою SEM та CM. Кристали мали довжину 46,4±15,2 проти 32,0±8,3 мкм, 28,03±8,2 проти 20,85±5,5 мкм завширшки та 6,62±2,9 проти 9,6±4,6 мкм завтовшки відповідно. Було визначено суттєві відмінності між вимірюваннями товщини SEM та CM (U=1283, p

Capsule endoscopy (CE) is the first-line diagnostic modality for detecting small bowel lesions. CE is non-invasive and does not require sedation, but its movements cannot be controlled, it requires a long time for interpretation, and it has lower image quality compared to wired endoscopy. With the rapid advancement of technology, several methods to solve these problems have been developed. This article describes the ongoing developments regarding external CE locomotion using magnetic force, artificial intelligence-based interpretation, and image-enhancing technologies with the CE system.

OBJECTIVE: The aims of this study were to visualize and quantify relative bone positions in the feet of individuals with cerebral palsy (CP) with a foot deformity and compare bone positions with those of typically developed (TD) controls. MATERIALS AND METHODS: Weight-bearing CT images of 14 individuals with CP scheduled for tendon transfer and/or bony surgery and of 20 TD controls were acquired on a Planmed Verity WBCT scanner. Centroids of the navicular and calcaneus with respect to the talus were used to quantify foot deformities. All taluses were aligned and the size and dimensions of the individuals' talus were scaled to correct for differences in bone sizes. In order to visualize and quantify variations in relative bone positions, 95% CI ellipsoids and standard deviations in its principle X-, Y-, and Z-directions were determined. RESULTS: In individuals with CP (age 11-17), a large variation in centroid positions was observed compared to data of TD controls. Radiuses of the ellipsoids, representing the standard deviations of the 95% CI in the principle X-, Y-, and Z-directions, were larger in individuals with CP compared to TD controls for both the calcaneus (3.16 vs 1.86 mm, 4.26 vs 2.60 mm, 9.19 vs 3.60 mm) and navicular (4.63 vs 1.55 mm, 5.18 vs 2.10 mm, 16.07 vs 4.16 mm). CONCLUSION: By determining centroids of the calcaneus and navicular with respect to the talus on WBCT images, normal and abnormal relative bone positions can be visualized and quantified in individuals with CP with various foot deformities.

Non-invasive fast imaging of grain microstructure of polycrystalline ceria with sub-micrometric spatial resolution is performed via time-domain Brillouin scattering. The propagation of a nanoacoustic pulse is monitored down to 8 μm deep in a 30 × 30 μm2 area. Grains boundaries are reconstructed in three-dimensions via a two-step processing method, relying on the wavelet synchro-squeezed transform and the alphashape algorithm. Imaging contrast is improved by taking advantage of stronger sensitivity to anisotropy of transverse acoustic waves, compared with longitudinal waves. Utilization of transverse waves in the image processing reveals additional boundaries, confirmed by an electron backscattering diffraction pattern but not discerned using longitudinal waves. A buried inclined interface between differently oriented grains is identified by monitoring changes in amplitude (phase) of the portion of the signal associated with transverse (longitudinal) waves. Estimates of the inclination angle of this interface prove the sensitivity of our laser ultrasonic method to image inclined boundaries.

Multiple-input multiple-output (MIMO) array synthetic aperture radar (SAR) can straightly obtain the 3-D imagery of the illuminated scene with the single-pass flight. Generally, the Rayleigh resolution of the elevation direction is unacceptable due to the length limitation of linear array. The super-resolution imaging algorithms within the compressive sensing (CS) framework have been extensively studied because of the essential spatial sparsity in the elevation direction. However, the super-resolution performance of the existing sparse reconstruction algorithms will deteriorate dramatically in the case of lower signal-to-noise ratio (SNR) level or a few antenna elements. To overcome this problem, a new super-resolution imaging structure based on CS and deep neural network (DNN) for MIMO array SAR is proposed in this article. In this new algorithm, the spatial filtering based on CS is first proposed to reserve the signals only impinging from the prespecified space subregions. Thereafter, a group of parallel end-to-end DNN regression models are designed for mapping the potential sparse recovery mathematical model and further locating the true scatterers in the elevation direction. Finally, extensive simulations and airborne MIMO array SAR experiments are investigated to validate that the proposed method can realize the state-of-the-art super-resolution imaging against other existing related methods.

Millimeter-wave (MMW) 3-D imaging technology is becoming a research hotspot in the field of safety inspection, intelligent driving, etc., due to its all-day, all-weather, high-resolution and non-destruction feature. Unfortunately, due to the lack of a complete 3-D MMW radar dataset, many urgent theories and algorithms (e.g., imaging, detection, classification, clustering, filtering, and others) cannot be fully verified. To solve this problem, this paper develops an MMW 3-D imaging system and releases a high-resolution 3-D MMW radar dataset for imaging and evaluation, named as 3DRIED. The dataset contains two different types of data patterns, which are the raw echo data and the imaging results, respectively, wherein 81 high-quality raw echo data are presented mainly for near-field safety inspection. These targets cover dangerous metal objects such as knives and guns. Free environments and concealed environments are considered in experiments. Visualization results are presented with corresponding 2-D and 3-D images; the pixels of the 3-D images are 512×512×6. In particular, the presented 3DRIED is generated by the W-band MMW radar with a center frequency of 79GHz, and the theoretical 3-D resolution reaches 2.8 mm × 2.8 mm × 3.75 cm. Notably, 3DRIED has 5 advantages: (1) 3-D raw data and imaging results; (2) high-resolution; (3) different targets; (4) applicability for evaluation and analysis of different post processing. Moreover, the numerical evaluation of high-resolution images with different types of 3-D imaging algorithms, such as range migration algorithm (RMA), compressed sensing algorithm (CSA) and deep neural networks, can be used as baselines. Experimental results reveal that the dataset can be utilized to verify and evaluate the aforementioned algorithms, demonstrating the benefits of the proposed dataset.

Background Dental implants are a common restorative method used to replace missing teeth. Implant placement techniques guided by three-dimensional imaging and navigation are becoming more widely available. Objective The present review focused on the following questions: 1. What are the advantages and disadvantages of 2-D versus 3-D imaging in dental implantology? 2. What are the advantages and disadvantages of freehand implant placement in comparison with navigation-guided implant placement? Methods A systematic review was performed, based on the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement. The following libraries were searched for relevant literature: PubMed, Embase, Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften (AWMF) Online, and the Cochrane Library. The risk of bias was assessed using the Scottish Intercollegiate Guidelines Network (SiGN) checklist. A total of 70 studies were included after screening, and the evidence from these was gathered for review. Results Three-dimensional imaging is advantageous in terms of image quality, and it provides a distortion-free evaluation of the implant site. However, it is also associated with higher costs and increased radiation exposure. Dynamic and static navigation are equal in accuracy and are both more accurate compared with the freehand method. No benefit in terms of implant survival could be demonstrated within the first 5 years for any specific method. Discussion A panoramic X-ray with a reference body often provides sufficient imaging and is the primary method for two-dimensional imaging. Cone beam computed tomography with low-dose protocol settings should be used if three-dimensional imaging is needed. Navigational support should be considered in the event of especially complex cases. Conclusion The guidance technique used for implant placement should be decided on an individual basis. With the increasing availability of three-dimensional imaging, there should also be an increase in awareness of radiation exposure.

The spread of high frame rate and 3-D imaging techniques has raised pressing requirements for ultrasound systems. In particular, the processing power and data transfer rate requirements may be so demanding to hinder the real-time (RT) implementation of such techniques. This paper first analyzes the general requirements involved in RT ultrasound systems. Then, it identifies the main bottlenecks in the receiving section of a specific RT scanner, the ULA-OP 256, which is one of the most powerful available open scanners and may therefore be assumed as a reference. This case study has evidenced that the “star” topology, used to digitally interconnect the system’s boards, may easily saturate the data transfer bandwidth, thus impacting the achievable frame/volume rates in RT. The architecture of the digital scanner was exploited to tackle the bottlenecks by enabling a new “ring“ communication topology. Experimental 2-D and 3-D high-frame-rate imaging tests were conducted to evaluate the frame rates achievable with both interconnection modalities. It is shown that the ring topology enables up to 4400 frames/s and 510 volumes/s, with mean increments of +230% (up to +620%) compared to the star topology.

Background: Vitamin D deficiency and altered body composition are common in Alzheimer’s disease (AD). Memantine with vitamin D supplementation can protect cortical axons against amyloid-β exposure and glutamate toxicity. Objective: To study the effects of vitamin D deprivation and subsequent treatment with memantine and vitamin D enrichment on whole-body composition using a mouse model of AD. Methods: Male APPswe/PS1dE9 mice were divided into four groups at 2.5 months of age: the control group (n = 14) was fed a standard diet throughout; the remaining mice were started on a vitamin D-deficient diet at month 6. The vitamin D-deficient group (n = 14) remained on the vitamin D-deficient diet for the rest of the study. Of the remaining two groups, one had memantine (n = 14), while the other had both memantine and 10 IU/g vitamin D (n = 14), added to their diet at month 9. Serum 25(OH)D levels measured at months 6, 9, 12, and 15 confirmed vitamin D levels were lower in mice on vitamin D-deficient diets and higher in the vitamin D-supplemented mice. Micro-computed tomography was performed at month 15 to determine whole-body composition. Results: In mice deprived of vitamin D, memantine increased bone mineral content (8.7% increase, p

Flow Mediated Dilation (FMD), a biomarker of endothelial function, consists of monitoring the brachial artery response to a transient occlusion. During this exam, the wall shear stress (stimulus) and diameter change (effect) should be simultaneously measured. Typically, both parameters are evaluated through the vessel longitudinal view, and the shear stress is estimated through the measurement of the centerline flow velocity, assuming a parabolic profile. Since the exam is relatively long, it is likely impaired by possible movements of the patient's arm. In this work, we have connected a 256-element sparse spiral array to the ULA-OP 256 scanner to implement a bi-plane imaging modality that, by exploiting both cross and longitudinal arterial views, allows reliable simultaneous measurements of diameter and flow profile. The improved robustness achieved by tracking the diameter on the cross-section view was demonstrated through phantom experiments and a preliminary in-vivo test.

Circulation is required for the delivery of oxygen and nutrition to tissues and organs, as well as waste collection. Therefore, the heart and vessels develop first during embryogenesis. The circulatory system consists of the heart, blood vessels, and blood cells, which originate from the mesoderm. The gene expression pattern required for blood vessel development is predetermined by the hierarchical and sequential regulation of genes for the differentiation of mesodermal cells. Herein, we review how blood vessels form distinctly in different tissues or organs of zebrafish and how vessel formation is universally or tissue-specifically regulated by signal transduction pathways and blood flow. In addition, the unsolved issues of mutual contacts and interplay of circulatory organs during embryogenesis are discussed.

Activation of κ opioid receptor (KOR) produces analgesia, antipruritic effect, sedation and dysphoria. To characterize neuroanatomy of KOR at high resolutions and circumvent issues of specificity of KOR antibodies, we generated a knock-in mouse line expressing KOR fused at the C terminus with the fluorescent protein tdTomato (KtdT). The selective KOR agonist U50,488H caused anti-scratch effect and hypolocomotion, indicating intact KOR neuronal circuitries. Clearing of brains with CLARITY revealed three-dimensional (3-D) images of distribution of KOR, and any G-protein-coupled receptors, for the first time. 3-D brain images of KtdT and immunohistochemistry (IHC) on brain sections with antibodies against tdTomato show similar distribution to that of autoradiography of [3H]U69,593 binding to KOR in wild-type mice. KtdT was observed in regions involved in reward and aversion, pain modulation, and neuroendocrine regulation. KOR is present in several areas with unknown roles, including the claustrum (CLA), dorsal endopiriform nucleus, paraventricular nucleus of the thalamus (PVT), lateral habenula (LHb), and substantia nigra pars reticulata (SNr), which are discussed. Prominent KtdT-containing fibers were observed to project from caudate putamen (CP) and nucleus accumbens (ACB) to substantia innominata (SI) and SNr. Double IHC revealed co-localization of KtdT with tyrosine hydroxylase (TH) in brain regions, including CP, ACB, and ventral tegmental area (VTA). KOR was visualized at the cellular level, such as co-localization with TH and agonist-induced KOR translocation into intracellular space in some VTA neurons. These mice thus represent a powerful and heretofore unparalleled tool for neuroanatomy of KOR at both the 3-D and cellular levels.

We present a wavenumber-domain iterative approach for rapid 3-D imaging of gravity anomalies and gradients data, which is based on the 3-D mesh model with a flat observational surface. The approach deconvolves the spectra of gravity anomalies or gradients by a 2-D deconvolution filter describing the spectrum of the imaging operator and then transforms the resultant spectra into the space domain to derive the density distribution. This 2-D deconvolution filtering is operated layer by layer from top to bottom in the subsurface and finally, all the results are merged to generate the 3-D density distribution. We improve previous 2-D deconvolution filters by involving a depth-scaling factor and utilize a priori constraint and the iteration algorithm for imaging, enable the presented approach to produce a density model with a considerable resolution and accuracy. The wavenumber-domain algorithm makes the imaging faster than the conventional space-domain inversions. Tests on the synthetic data and the real data from a metallic deposit area in Northwest China verified the feasibility and high efficiency of the presented approach.

Array Synthetic Aperture Radar (ASAR) system radar imaging field has gained attention because of its three-dimensional (3-D) imaging ability. A novel Circular Array SAR (CASAR) system is employed for 3-D high-resolution radar imaging to overcome the drawbacks exhibited by linear array SAR in high-resolution imaging and by circular SAR in side-lobe suppression. Point Spread Function (PSF) model based on the CASAR system is derived, and the advantages of the new configuration of the circular array in 3-D imaging are theoretically analyzed. Prototype CASAR experimental system is built on the basis of the abovementioned analysis. PSF simulation experiments and outdoor 3-D CASAR imaging experiments under outdoor conditions are performed to verify performance of the CASAR system in 3-D SAR imaging. Compared imaging results acquired using linear array SAR, circular SAR, and CASAR system proves that the CASAR system has highresolution 3-D SAR images and demonstrates effective side-lobe suppression capability.

Objective.High-resolution peripheral quantitative computed tomography (HR-pQCT) has the potential to improve radiographic progression determination in clinical trials and longitudinal observational studies. The goal of this work was to describe the current state of research presented at Outcome Measures in Rheumatology (OMERACT) 2016 and ensuing future directions outlined during discussion among attendees.Methods.At OMERACT 2016, SPECTRA (Study grouP for xtrEme-Computed Tomography in Rheumatoid Arthritis) introduced efforts to (1) validate the HR-pQCT according to OMERACT guidelines, focusing on rheumatoid arthritis (RA), and (2) find alternatives for automated joint space width (JSW) analysis. The Special Interest Group (SIG) was presented to patient research partners, physicians/researchers, and SIG leaders followed by a 40-min discussion on future directions.Results.A consensus definition for RA erosion using HR-pQCT was demonstrated through a systematic literature review and a Delphi exercise. Histopathology and perfusion studies were presented that analyzed the true characteristics of cortical breaks in HR-pQCT images, and to provide criterion validity. Results indicate that readers were able to discriminate between erosion and small vascular channels. Moderate reliability (ICC 0.206–0.871) of direct erosion size measures was shown, which improved (> 0.9) only when experienced readers were considered. Quantification of erosion size was presented for scoring, direct measurement, and volumetric approaches, as well as a reliability exercise for direct measurement. Three methods for JSW measurement were compared, all indicating excellent reproducibility with differences at the extremes (i.e., near-zero and joint edge thickness).Conclusion.Initial reports on HR-pQCT are promising; however, to consider its use in clinical trials and longitudinal observational studies, it is imperative to assess the responsiveness of erosion measurement quantification.

In the last two decades, thanks to the considerable technological development of solid-state sensors, digital holography (DH) has gained credits as the elective imaging technique for applications in various research fields, e.g., material science, biotechnology, as well as a diagnostic tool for applications at lab-on-a-chip scale. However, since its beginning, the intrinsic coherent nature of holography made 3-D imaging and display one of its preferred applications. Still today, several research groups around the world are working to develop novel numerical solutions in the framework of DH-based 3-D imaging and display technology. In this paper, we report an overview of the most important contributions given to this field over the last years.

Purpose Early-onset degeneration of the knee is linked to genetics, overload, injury, and potentially, knee morphology. The purpose of this study is to explore the characteristics of the small medial femoral condyle, as a distinct knee morphotype, by means of a landmark-based three-dimensional (3D) analysis and statistical parametric mapping. Methods Sixteen knees with a small medial femoral condyle (SMC) were selected from a database of patients with distinct knee joint anatomy and 16 gender-matched knees were selected from a control group database. 3D models were generated from the medical imaging. After normalization for size, a set of pre-defined landmark-based parameters was analysed for the femur and tibia. Local shape differences were evaluated by matching all bone surfaces onto each other and comparing the distances to the mean control group bone shape. Results The small medial condyle group showed a significant association with medial compartment degeneration and had a 4% and 13% smaller medial condyle anteroposteriorly and mediolaterally, whereas the distal femur was 3% wider mediolaterally. The lateral condyle was 2% smaller anteroposteriorly and 8% wider mediolaterally. The complete tibial plateau was 3% smaller mediolaterally and the medial tibial plateau was 6% smaller. Conclusion A new knee morphotype demonstrated an increased risk for medial compartment degeneration and was differentiated from a healthy control group based on the following morphological characteristics: a smaller medial femoral condyle and medial tibial plateau, a wider lateral femoral condyle and a wider distal femur on a smaller tibial plateau. This pilot study suggests a role for the SMC knee morphotype in the multifactorial process of medial compartment degeneration. Level of evidence III

3-D imaging with irregular planar multiple-input-multiple-output (MIMO) arrays is discussed. Due to signal acquisition on irregular spatial sampling grids by using these antenna arrays, the fast Fourier transform (FFT)-based imaging algorithms cannot readily be used for image formation. To avoid the application of computationally intensive coherent summation algorithms such as filtered backprojection or Kirchhoff migration, we propose a nonuniform FFT (NUFFT)-based MIMO Range Migration Algorithm (i.e., NUFFT-based MIMO-RMA) for efficient microwave imaging. The algorithm exploits NUFFT to reconstruct the wavenumber-domain spectra related to each Fourier frequency. It is generic and applicable to 3-D imaging with irregular planar MIMO arrays. The effects of irregular spatial sampling and signal bandwidth on the imaging performance and computational efficiency of the proposed algorithm are analyzed. Finally, some numerical simulations and experimental results are presented to demonstrate the performance of the proposed imaging algorithm.

Objective: The present study aims at using cone beam computed tomography (CBCT) to analyze the maxillomandibular characteristics present in adults with mandibular asymmetries and different sagittal jaw relationships. Methods: 360 patients were selected and divided into three groups (Class I, Class II, and Class III), with 120 individuals per group. The groups were then subdivided according to the intensity of lateral deviation of the gnathion point, into: 1) relative symmetry, 2) moderate asymmetry, and 3) severe asymmetry. Three planes of reference were established in the CBCT images and several measurements were taken to compare the bilateral skeletal differences between the intensities of asymmetry for the different sagittal jaw relationships. Results: When the groups were compared by the intensity of asymmetry, significant differences among patients with relative symmetry and moderate to severe asymmetry were found. This was especially noticed for severe asymmetry, suggesting that the deviation of the chin did not constitute the only morphological alteration for these patients, especially because a series of measurements showed significant bilateral differences. When comparing sagittal jaw relationships, the only significant finding was the vertical positioning of the gonion between Class II and III patients with severe asymmetry. Conclusions: When comparing the three sagittal jaw relationships with the same intensity of asymmetry, most maxillofacial aspects were quite similar. The only difference was found for patients with severe asymmetry, as the individuals with Class II showed greater bilateral difference in the vertical positioning of the gonion, when compared to patients with Class III. RESUMO Objetivo: o presente estudo teve como objetivo analisar, por meio de tomografia computadorizada de feixe cônico (TCFC), as características esqueléticas maxilomandibulares presentes em adultos com diferentes graus de assimetria mandibular e diferentes relações esqueléticas sagitais. Métodos: foram selecionados 360 pacientes, os quais foram divididos em três grupos, com 120 indivíduos cada (Classe I, Classe II e Classe III). Cada grupo foi, ainda, subdividido de acordo com a intensidade do desvio lateral do mento: 1) simetria relativa; 2) assimetria moderada; e 3) assimetria severa. Três planos de referência foram estabelecidos nas imagens de TCFC e várias medidas foram realizadas, sendo comparadas as diferenças esqueléticas bilaterais existentes entre os graus de assimetria em cada grupo, nas diferentes relações esqueléticas sagitais. Resultados: quando comparados os grupos pelos graus de assimetria, existiram diferenças significativas entre pacientes com simetria relativa e pacientes assimétricos, especialmente para a assimetria severa, sugerindo que o desvio do mento não constitui a única alteração morfológica para esses pacientes, especialmente porque uma série de medidas apresentou diferenças bilaterais significativas. Quando comparadas as relações sagitais entre si, não foram encontradas diferenças significativas, exceto para o posicionamento vertical do gônio entre as Classe II e III na assimetria severa. Conclusão: ao comparar a mesma intensidade de assimetria entre as diferentes relações esqueléticas sagitais, pouca diferença pôde ser observada. A única diferença encontrada foi em pacientes com assimetria severa, na qual os indivíduos com Classe II apresentaram maior diferença bilateral no posicionamento vertical do gônio, quando comparados àqueles com Classe III.

In this paper, three-dimensional (3-D) multiple-input multiple-output (MIMO) radar accurate localization and imaging method with motion parameter estimation is proposed for targets with complex motions. To characterize the target accurately, a multi-dimensional signal model is established including the parameters on target 3-D position, translation velocity, and rotating angular velocity. For simplicity, the signal model is transformed into three-joint two-dimensional (2-D) parametric models by analyzing the motion characteristics. Then a gridless method based on atomic norm optimization is proposed to improve precision and simultaneously avoid basis mismatch in traditional compressive sensing (CS) techniques. Once the covariance matrix is obtained by solving the corresponding semi-definite program (SDP), estimating signal parameters via rotational invariance techniques (ESPRIT) can be used to estimate the positions, then motion parameters can be obtained by Least Square (LS) method, accordingly. Afterwards, pairing correction is carried out to remove registration errors by setting judgment conditions according to resolution performance analysis, to improve the accuracy. In this way, high-precision imaging can be realized without a spectral search process, and any slight changes of target posture can be detected accurately. Simulation results show that proposed method can realize accurate localization and imaging with motion parameter estimated efficiently.

This study evaluates the volumetric imaging performance of two prototyped 62 + 62 row–column-addressed (RCA) 2-D array transducer probes using three synthetic aperture imaging (SAI) emission sequences and two different beamformers. The probes are fabricated using capacitive micromachined ultrasonic transducer (CMUT) and piezoelectric transducer (PZT) technology. Both have integrated apodization to reduce ghost echoes and are designed with similar acoustical features, i.e., 3-MHz center frequency, $\lambda $ /2 pitch, and $24.8\times 24.8\,\,\text {mm}^{2}$ active footprint. Raw RF data are obtained using an experimental research ultrasound scanner, SARUS. The SAI sequences are designed for imaging down to 14 cm at a volume rate of 88 Hz. Two beamforming methods, spatial matched filtering and row–column adapted delay-and-sum, are used for beamforming the RF data. The imaging quality is investigated through simulations and phantom measurements. Both probes on average have similar lateral full-width at half-maximum (FWHM) values, but the PZT probe has 20% smaller cystic resolution values and 70% larger contrast-to-noise ratio (CNR) compared to the capacitive micromachined ultrasonic transducer (CMUT) probe. The CMUT probe can penetrate down to 15 cm, and the PZT probe down to 30 cm. The CMUT probe has 17% smaller axial FWHM values. The matched filter focusing shows an improved B-mode image for measurements on a cyst phantom with an improved speckle pattern and better visualization of deeper lying cysts. The results of this study demonstrate the potentials of RCA 2-D arrays against fully addressed 2-D arrays, which are low channel count (e.g., 124 instead of 3844), low acoustic intensity mechanical index (MI ≤ 0.88 and spatial-peak-temporal-average intensity $I_{\text {spta}}\leq 5.5~\text {mW/cm}^{2}$ ), and high penetration depth (down to 30 cm), which makes 3-D imaging at high volume rates possible with equipment in the price range of conventional 2-D imaging.

Equipped with a 1-meter Cassegrain telescope with 6.2 meter focal length and an electronically gated Intensified Charge-Coupled Device (ICCD), a multilayer Na imager is designed and developed at Wuhan in China. This novel instrument has successfully achieved the first preliminary 3-D image of the mesospheric Sodium (Na) layer when running alongside a Na lidar. The vertical Na layer profile is measured by the lidar, while the horizontal structure of the layer at different altitudes is measured by the ICCD imaging with a horizontal resolution of ~3.7 urad. In this experiment, controlled by the delay and width of the ICCD gating signal, the images of the layer are taken with three-second temporal resolution for every 5 km. The results show highly variable structures in both the vertical and horizontal directions within the Na layer. Horizontal images of the Na layer at different altitudes near both the permanent layer (80–100 km) and a sporadic Na layer at 117.5 km are obtained simultaneously for the first time. The Na number density profiles measured by the lidar and those derived from this imaging technique show excellent agreement, demonstrating the success of this observational technique and the first 3-D imaging of the mesospheric Na layer.

We designed a ground-based radar system with a C-band 2-D cross multiple input multiple output (MIMO) array for 3-D imaging and displacement estimation purposes. For this system, we developed a far-field pseudo-polar image format algorithm using pseudo-polar spherical coordinate. The use of a tensor compressive sensing technique allows to focus under-sampled raw data and to optimize the data acquisition time and memory usage. A novel algorithm, named as tensor-based iterative adaptive approach, is proposed for the effective and efficient reconstruction of sparse targets with a reduced level of sidelobes. Experimental results validate the designed radar system and the proposed algorithms.

Real‐time assessment of excised tissue may help to improve surgical results in breast tumor surgeries. Here, as a step towards this purpose, the potential of second and third harmonic generation (SHG, THG) microscopy is explored. SHG and THG are nonlinear optical microscopic techniques that do not require labeling of tissue to generate 3D images with intrinsic depth‐sectioning at sub‐cellular resolution. Until now, this technique had been applied on fixated breast tissue or to visualize the stroma only, whereas most tumors start in the lobules and ducts. Here, SHG/THG images of freshly excised unprocessed healthy human tissue are shown to reveal key breast components—lobules, ducts, fat tissue, connective tissue and blood vessels, in good agreement with hematoxylin and eosin histology. DNA staining of fresh unprocessed mouse breast tissue was performed to aid in the identification of cell nuclei in label‐free THG images. Furthermore, 2‐ and 3‐photon excited auto‐fluorescence images of mouse and human tissue are collected for comparison. The SHG/THG imaging modalities generate high quality images of freshly excised tissue in less than a minute with an information content comparable to that of the gold standard, histopathology. Therefore, SHG/THG microscopy is a promising tool for real‐time assessment of excised tissue during surgery., Most breast cancers are carcinomas, a type of cancer that is derived from epithelial cells, aligning ducts and lobules. This study shows that second and third harmonic generation (SHG/THG) microscopy reveals the morphology of those key structures in freshly excised, unprocessed human breast tissue, including their cells and cell nuclei. The SHG/THG images have an information content comparable to that of the gold standard, (H&E histology) but are generated much faster, in less than a minute.

The tomographic algorithms commonly used to process ground penetrating radar (GPR) data assume the scattering phenomenon activated by ideal sources. This can be considered an adequately accurate assumption if the actual GPR antenna presents almost nondirectional features, but should instead properly revisited when a target is illuminated by means of more collimated near-field distributions. In this work, moving from the recent advancements done for two-dimensional scalar GPR imaging theory, we propose a three-dimensional (3-D) vector formulation of the scattering equation, modeling the incident field with the actual field radiated by a directional antenna. Both 3-D dielectric and metallic targets are reconstructed in challenging environments by considering multi-frequency data at microwaves. A comparative analysis is developed through the processing of numerical data by means of a singular-value decomposition as well as an adjoint-operator scheme. The effectiveness of these methods is assessed considering full-wave synthetic data generated on a customized virtual setup based on a commercial tool.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SYNERGIE [Axe_IRSTEA]TETIS-ATTOS [ADD1_IRSTEA]Dynamiques spatiales d'anthropisation; International audience; This paper concerns processing techniques for the the characterization of a tropical forest using Po1TomSAR data at P band. In particular, existing forest biomass estimation methods, relating biomass to sampled tomographic intensity values, are revisited using simple methodological step sand an adaptive tomographic intensity sampling approach. The canopy reflectivity sampling location is determined as a function of the effective forest height and of the tomographic resolution, in order to compensate geometrical mismatches. Moreover, an adaptive polarimetric decomposition technique is used to further decouple the sampled intensity from ground and topographic tomographic scattering effects. The performance of the proposed techniques is assessed using TROPISAR P-band data acquired by the ONERA's SETHI sensor over the Paracou data site in French Guiana in 2009. Results indicate over this site a substantial reduction of the Above Ground Biomass (AGB) estimation error, with respect to existing techniques.

International audience; This paper summarizes a set of studies led on the topic of polarimetric coherence optimization for the coherent processing of stacks of polarimetric SAR images. It is shown that coherence maximization may be understood differently depending on the application at hand. Extracting polarimetric coherent signals embedded in noise or in a severe background requires to use polarimetric diversity as a supplementary mean for discovering organized speckles patterns, whereas classical MB-PolinSAR coherence optimization gives more importance to the polarimetric scattering mechanisms that extremize coherence values. This paper reviews different techniques able to cope with an arbitrary number of images and that are characterized by their low degree of computational complexity, conferred by the favored use of analytical solutions. The usefulness of these techniques is demonstrated using various kinds of applications to real spaceborne and airborne data sets.

OBJECTIVES The aim of the present randomized controlled trial (RCT) was therefore the tridimensional evaluation of soft tissue changes after rapid maxillary expansion in growing patients. SETTING AND SAMPLE POPULATION Treated group comprised 17 patients (10 males and 7 females) with a mean age of 9.8 ± 1.2 years, and control group comprised 17 patients (13 males and 4 females) with a mean age of 9.1 ± 2.1 years. MATERIAL & METHODS All patients of the treated group underwent maxillary expansion with Haas-type expander while patients of the control group underwent no treatment. 3D facial scans were acquired at T1, at the beginning of treatment or observation period, and at T2, 18 months apart. The mean interval between the timepoints was 18.2 ± 0.4 months. RESULTS The main differences between groups were reported in the nasal area. Nasal width (Alr-All) significantly increased in the treated group compared with the control. The increase in intereye and mouth width in the study group did not show differences with the control group. No significant differences were reported for lips' protrusion, angular measurements and facial heights between groups. The total nose volume difference was significantly higher in the treated group compared with control, and this result was related mainly to the significant increase in the nasal dorsum volume. CONCLUSION Maxillary expansion produced significant increase in the nasal base and nasal volumes, but its clinical relevance is still questionable.

We have designed and implemented a dual-mode adaptive optics (AO) imaging system that combines spectral domain optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) for in vivo imaging of the human retina. The system simultaneously acquires SLO frames and OCT B-scans at 60Hz with an OCT volume acquisition time of 4.2s. Transverse eye motion measured from the SLO is used to register the OCT B-scans to generate three-dimensional (3-D) volumes. Key optical design considerations include: minimizing system aberrations through the use of off-axis relay telescopes, conjugate pupil plane requirements, and the use of dichroic beam splitters to separate and recombine the OCT and SLO beams around the nonshared horizontal scanning mirrors. To demonstrate system performance, AO-OCT-SLO images and measurements are taken from three normal human subjects ranging in retinal eccentricity from the fovea out to 15-deg temporal and 20-deg superior. Also presented are en face OCT projections generated from the registered 3-D volumes. The ability to acquire high-resolution 3-D images of the human retina in the midperiphery and beyond has clinical importance in diseases, such as retinitis pigmentosa and cone-rod dystrophy.

A direct-detection 3-D imaging lidar is capable of acquiring a depth image of noncooperative targets in long distance, using Geiger mode avalanche photodiodes and the technique of time-correlated single-photon counting. However, conventional 3-D imaging lidar has a long data acquisition time. This paper introduces a spatially adaptive method to obtain target profile rapidly for 3-D imaging lidar by exploiting discontinuities between targets and background in the depth domain. The idea behind our strategy is using an adaptive scanning step to localize the regions near the depth boundaries and perform fine scans only to these regions. Fine scans only for those specific regions ensure the recovery accuracy while consuming much less data acquisition time, compared to a conventional high-resolution scanning lidar. Experimental results demonstrate that for the experimental scene, the data acquisition time decreases 85% by using the proposed method, without generating much distortion of the target profile. This method may be of considerable value to fields that need fast 3-D imaging, such as remote sensing and military reconnaissance.

The concept of Geosynchronous Circular SAR (Geo-CSAR) is introduced in this paper. With the design of the geosynchronous orbit parameters, a near-circular satellite sub-track could be formed to enable the staring imaging mode, which supports the advanced applications for wide-field and 3-D information acquisition under long-term consistent observation. This paper also analyzes Geo-CSAR's imaging formation capabilities, and concludes its attractive advantages over low-earth orbit spaceborne SAR in terms of instantaneous coverage, consistent observing area, 3-D positioning accuracy and etc.. Encouraging expectations for Geo-CSAR thus could be positively predicted in military investigation and disaster monitoring management applications.

Background Although intracavitary radiotherapy (ICR) is essential for the radiation therapy of cervical cancer, few institutions in Korea perform 3-dimensional (3D)-based ICR. To identify patients who would benefit from 3D-based ICR, dosimetric parameters for tumor targets and organs at risk (OARs) were compared between 2-dimensional (2D)- and 3D-based ICR. Methods Twenty patients with locally advanced cervical cancer who underwent external beam radiation therapy (EBRT) following 3D-based ICR were retrospectively evaluated. New 2D-based plans based on the Manchester system were developed. Tumor size was measured by magnetic resonance imaging. Results The mean high risk clinical target volume (HR-CTV) D90 value was about 10% lower for 2D- than for 3D-based plans (88.4% vs. 97.7%; P = 0.068). Tumor coverage did not differ between 2D- and 3D-based plans in patients with tumors ≤ 4 cm at the time of brachytherapy, but the mean HR-CTV D90 values in patients with tumors > 4 cm were significantly higher for 3D-based plans than for 2D-based plans (96.0% vs. 78.1%; P = 0.017). Similar results were found for patients with tumors > 5 cm initially. Other dosimetric parameters for OARs were similar between 2D- and 3D-based plans, except that mean sigmoid D2cc was higher for 2D- than for 3D-based plans (67.5% vs. 58.8%; P = 0.043). Conclusion These findings indicate that 3D-based ICR plans improve tumor coverage while satisfying the dose constraints for OARs. 3D-based ICR should be considered in patients with tumors > 4 cm size at the time of brachytherapy or > 5 cm initially., Graphical Abstract

Imaging of bone metastasis response to therapy is a research priority. Stradwin is a new software-tool, with demonstrated sub-voxel accuracy in assessing cortical bone properties from routine CT. We applied this technology to the context of osseous metastases, with particular focus on disease progression using prostate cancer as a model. 3D–rendered ‘bone-maps’ were produced for 20 men with advanced prostate cancer, including a sub-cohort of 9 who had undergone serial scans. Correlation between baseline interpretation and assessments of progression between modalities was assessed. Bone-maps took significantly less time to interpret than CT bone windows (P

To evaluate brain atrophy in anorexic patients by automated cerebral segmentation with the magnetization-prepared 2 rapid acquisition gradient echo (MP2RAGE) MRI sequence. Twenty patients (female; mean age, 27.9 years), presenting consecutively for brain MRI between August 2014-December 2016 with clinical suspicion of anorexia nervosa and BMI < 18.5 kg/m(2) were included. Controls were ten healthy females (mean age, 26.5 years). Automated brain morphometry was performed based on MP2RAGE. Means of morphometric results in the two groups were compared and correlation with BMI was analysed. Significantly lower volumes of total brain, grey matter (GM), white matter (WM), cerebellum and insula were found in anorexic patients. Anorexics had higher volumes of CSF, ventricles, lateral ventricles and third ventricle. When adjusted means for weight and height were compared, the volume of WM and cerebellum were not significantly different. However, volume of WM was significantly affected by weight and positively correlated with BMI. Significant positive correlations were found between BMI and volumes of total brain, GM, cortical GM and WM. BMI was negatively correlated with volumes of CSF and third ventricle. Brain atrophy was demonstrated in anorexic patients with MP2RAGE-based automated segmentation, which seems to reliably estimate brain volume. aEuro cent Automated brain segmentation based on 3-D MRI seems to reliably estimate brain volume. aEuro cent This technique detected brain atrophy in patients suffering from anorexia nervosa. aEuro cent Brain changes in anorexia nervosa can be quantitatively and qualitatively followed-up by MRI.

25th Signal Processing and Communications Applications Conference (SIU) -- MAY 15-18, 2017 -- Antalya, TURKEY, WOS: 000413813100056, In recent years, breast cancers have been diagnosed by several imaging modalities. One of these imaging methods is the diffuse optical tomography (DOT) system. In the presented study, in-vitro data were acquired from a breast phantom using the our designed DOT system. Breast phantoms were reconstructed in three dimensions (3D) using Truncated Conjugate Gradient (TCG) reconstruction algorithm. Then, image processing methods were applied to the raw images. Image segmentation technique was used to distinguish between "object" and "backgrounds". Later, 3D Gaussian filtering was applied to smooth the image and reduce noise. Finally, a three dimensional interpolation was applied to the noise free images in order to obtain a more realistic 3D image of the tissue phantoms. Thus, we have modified most popular image processing methods to apply the DOT images. As a result, we obtained user friendly, fast, accurate and user independent images processing methods for the DOT systems., Turk Telekom, Arcelik A S, Aselsan, ARGENIT, HAVELSAN, NETAS, Adresgezgini, IEEE Turkey Sect, AVCR Informat Technologies, Cisco, i2i Syst, Integrated Syst & Syst Design, ENOVAS, FiGES Engn, MS Spektral, Istanbul Teknik Univ

25th Signal Processing and Communications Applications Conference, SIU 2017 -- 15 May 2017 through 18 May 2017 -- -- 128703, In recent years, breast cancers have been diagnosed by several imaging modalities. One of these imaging methods is the diffuse optical tomography (DOT) system. In the presented study, in-vitro data were acquired from a breast phantom using the our designed DOT system. Breast phantoms were reconstructed in three dimensions (3D) using Truncated Conjugate Gradient (TCG) reconstruction algorithm. Then, image processing methods were applied to the raw images. Image segmentation technique was used to distinguish between 'object' and 'backgrounds'. Later, 3D Gaussian filtering was applied to smooth the image and reduce noise. Finally, a three dimensional interpolation was applied to the noise free images in order to obtain a more realistic 3D image of the tissue phantoms. Thus, we have modified most popular image processing methods to apply the DOT images. As a result, we obtained user friendly, fast, accurate and user independent images processing methods for the DOT systems

In this paper, to deal with the concealed target detection problem, an accurate and efficient algorithm for near-field millimeter wave three-dimensional (3-D) imaging is proposed that uses a two-dimensional (2-D) plane antenna array. First, a two-dimensional fast Fourier transform (FFT) is performed on the scattered data along the antenna array plane. Then, a phase shift is performed to compensate for the spherical wave effect. Finally, fast Gaussian gridding based nonuniform FFT (FGG-NUFFT) combined with 2-D inverse FFT (IFFT) is performed on the nonuniform 3-D spatial spectrum in the frequency wavenumber domain to achieve 3-D imaging. The conventional method for near-field 3-D imaging uses Stolt interpolation to obtain uniform spatial spectrum samples and performs 3-D IFFT to reconstruct a 3-D image. Compared with the conventional method, our FGG-NUFFT based method is comparable in both efficiency and accuracy in the full sampled case and can obtain more accurate images with less clutter and fewer noisy artifacts in the down-sampled case, which are good properties for practical applications. Both simulation and experimental results demonstrate that the FGG-NUFFT-based near-field 3-D imaging algorithm can have better imaging performance than the conventional method for down-sampled measurements.

This paper presents a study of the processing chain for ice and glacier structures in the holographic SAR tomography (HoloSAR) mode. The algorithm is mainly based on the fast factorized back-projection (FFBP) to solve a three-dimensional space using fully polarimetric data. The motivation of HoloSAR in the cryosphere is mainly driven by recent investigations that have shown the capabilities of this mode to obtain 3-D imaging reconstructions of volumes over 360 ° at very high resolution. In this regard, a HoloSAR campaign was conducted at L-/P-band by DLR's F-SAR sensor in K-Transect, Greenland. The first experimental results of this study show a polarimetric analysis of the resulting images of a single circular flight, where the arc- and circular patterns of the 2-D images in the (x, y) plane already indicate significant wave penetration. The second part presents 3-D images obtained by the combination of the circular and vertical synthetic apertures, which enable an estimation of the vertical profile of the glacier. This mode potentially allows for a more accurate estimation of the vertical profile of ice sheets and bedrock.

We experimentally demonstrate the possibility of reconstructing 3-D scenes using integral imaging from very photon-starved scenes. It is shown that by using an iterative reconstruction algorithm, it is possible to reconstruct 3-D objects captured with an optical signal just above the CCD image sensors' noise level. Three-dimensional scene reconstruction with integral images with only a few photons per pixel of the image sensor is demonstrated. Optical experimental results are presented.

International audience; Objective: To prove the feasibility of 3D reconstructions of the diaphragm during respiratory cycle, using EPI sequences. Materials and Methods: EPI acquisition, 270 ms/image, on a healthy subject breathing spontaneously and at 0.1Hz. Continuously recorded respiratory signal allowed for retrospective synchronization with respiratory phases for reconstruction of successive diaphragm surfaces using a specifically designed software. Displacements, area and volume changes of the diaphragm were quantified. Results: Our measurements were comparable with literature data. Reconstructed surfaces allowed in vivo diaphragm dynamics evaluation, in terms of displacements, area and volume variations. Conclusion: EPI has adequate spatial and temporal resolution for studying diaphragm dynamics during natural breathing.