Three-dimensional Imaging System Research Articles

Noncontact diffuse correlation tomography of human breast tumor.

Our first step to adapt our recently developed noncontact diffuse correlation tomography (ncDCT) system for three-dimensional (3-D) imaging of blood flow distribution in human breast tumors is reported. A commercial 3-D camera was used to obtain breast surface geometry, which was then converted to a solid volume mesh. An ncDCT probe scanned over a region of interest on the mesh surface and the measured boundary data were combined with a finite element framework for 3-D image reconstruction of blood flow distribution. This technique was tested in computer simulations and in vivo human breasts with low-grade carcinoma. Results from computer simulations suggest that relatively high accuracy can be achieved when the entire tumor is within the sensitive region of diffuse light. Image reconstruction with a priori knowledge of the tumor volume and location can significantly improve the accuracy in recovery of tumor blood flow contrasts. In vivo imaging results from two breast carcinomas show higher average blood flow contrasts (5.9- and 10.9-fold) in the tumor regions compared to the surrounding tissues, which are comparable with previous findings using diffuse correlation spectroscopy. The ncDCT system has the potential to image blood flow distributions in soft and vulnerable tissues without distorting tissue hemodynamics

Use of fluoroscopy in clinical electrophysiology in Europe: results of the European Heart Rhythm Association Survey.

Despite the advent of non-fluoroscopic technologies, fluoroscopy remains the cornerstone of imaging in most interventional electrophysiological procedures, from diagnostic studies to ablation interventions and device implantation. The purpose of the European Heart Rhythm Association survey was to provide an insight into regulatory policies and physicians' clinical practice when using fluoroscopy during ablation procedures and device implantation. The survey has shown that only 50% of the participating centres worked with low frame rates (3-6 frames per second) and that the left anterior oblique projection, with higher radiation exposure for the physician, is used for nearly every ablation target. Although three-dimensional imaging systems may reduce the radiation exposure, most centres never used these systems for standard ablation procedures and a trend is that non-fluoroscopy technologies are even less frequently used than in 2012, when the use of robotic systems was still rare. Even less costly equipment such as lead gloves, lead glass cabins, or radiation absorbing pads are still not routinely used.

Non-contact scanning diffuse correlation tomography system for three-dimensional blood flow imaging in a murine bone graft model.

A non-contact galvanometer-based optical scanning system for diffuse correlation tomography was developed for monitoring bone graft healing in a murine femur model. A linear image reconstruction algorithm for diffuse correlation tomography was tested using finite-element method based simulated data and experimental data from a femur or a tube suspended in a homogeneous liquid phantom. Finally, the non-contact system was utilized to monitor in vivo blood flow changes prior to and one week after bone graft transplantation within murine femurs. Localized blood flow changes were observed in three mice, demonstrating a potential for quantification of longitudinal blood flow associated with bone graft healing.

Three-Dimensional Optoacoustic and Laser-Induced Ultrasound Tomography System for Preclinical Research in Mice: Design and Phantom Validation.

In this work, we introduce a novel three-dimensional imaging system for in vivo high-resolution anatomical and functional whole-body visualization of small animal models developed for preclinical and other type of biomedical research. The system (LOUIS-3DM) combines a multiwavelength optoacoustic tomography (OAT) and laser-induced ultrasound tomography (LUT) to obtain coregistered maps of tissue optical absorption and speed of sound, displayed within the skin outline of the studied animal. The most promising applications of the LOUIS-3DM include 3D angiography, cancer research, and longitudinal studies of biological distributions of optoacoustic contrast agents.

Speckle contrast diffuse correlation tomography of complex turbid medium flow.

Developed herein is a three-dimensional (3D) flow contrast imaging system leveraging advancements in the extension of laser speckle contrast imaging theories to deep tissues along with our recently developed finite-element diffuse correlation tomography (DCT) reconstruction scheme. This technique, termed speckle contrast diffuse correlation tomography (scDCT), enables incorporation of complex optical property heterogeneities and sample boundaries. When combined with a reflectance-based design, this system facilitates a rapid segue into flow contrast imaging of larger, in vivo applications such as humans. A highly sensitive CCD camera was integrated into a reflectance-based optical system. Four long-coherence laser source positions were coupled to an optical switch for sequencing of tomographic data acquisition providing multiple projections through the sample. This system was investigated through incorporation of liquid and solid tissue-like phantoms exhibiting optical properties and flow characteristics typical of human tissues. Computer simulations were also performed for comparisons. A uniquely encountered smear correction algorithm was employed to correct point-source illumination contributions during image capture with the frame-transfer CCD and reflectance setup. Measurements with scDCT on a homogeneous liquid phantom showed that speckle contrast-based deep flow indices were within 12% of those from standard DCT. Inclusion of a solid phantom submerged below the liquid phantom surface allowed for heterogeneity detection and validation. The heterogeneity was identified successfully by reconstructed 3D flow contrast tomography with scDCT. The heterogeneity center and dimensions and averaged relative flow (within 3%) and localization were in agreement with actuality and computer simulations, respectively. A custom cost-effective CCD-based reflectance 3D flow imaging system demonstrated rapid acquisition of dense boundary data and, with further studies, a high potential for translatability to real tissues with arbitrary boundaries. A requisite correction was also found for measurements in the fashion of scDCT to recover accurate speckle contrast of deep tissues.

Ultrafast Three-Dimensional Imaging System Based on Phase-Shifting Method and Hybrid Dispersion Laser Scanning

In this paper, we proposed an ultrafast 3-D imaging system based on phase-shifting method and a hybrid dispersion scanning technique. The imaging system is capable of acquiring the 3-D shape of the object at an ultrafast scan rate. A theoretical model is built to describe the operation principle of the imaging system and to analyze the performance of the system. In the demonstration, the imaging system is designed with practical devices and components. The system has a scan rate of 25 MHz and a frame rate of 100 kHz. The field of view is 50 μm × 50 μm, and the number of pixels of one frame is 260 pixel × 1000 pixel. The reconstructed 3-D image has the peak signal-to-noise ratio (PSNR) of 30.11 dB. The performance of the imaging system is investigated by analyzing the influence of the input beam size and the resolution of the digitizer. The input collimated light with large beam size is preferred for high image quality. Moreover, the depth resolution can be improved by using high-resolution digital signal processing.

Feature Extraction from Multiply Focal Images by Using a Liquid Crystal Lens

Three-dimensional imaging system in combination with a digital image processing is developed for determining all-focused and depth mapping properties by using a low-voltage-driving liquid crystal lens with a variable focal length. The continuous focused photo images without the magnification and reduction are taken by applying voltages to the electrodes of the LC lens and tuning a focal plane in a depth direction. The sharp and clear all-focused image can be obtained by processing an image digital filter from continuous focal images. The depth mapping properties can also be derived by our technique.

Prediction of Android and Gynoid Body Adiposity via a Three-dimensional Stereovision Body Imaging System and Dual-Energy X-ray Absorptiometry

Objective: Current methods for measuring regional body fat are expensive and inconvenient compared to the relative cost-effectiveness and ease of use of a stereovision body imaging (SBI) system. The primary goal of this research is to develop prediction models for android and gynoid fat by body measurements assessed via SBI and dual-energy x-ray absorptiometry (DXA). Subsequently, mathematical equations for prediction of total and regional (trunk, leg) body adiposity were established via parameters measured by SBI and DXA.Methods: A total of 121 participants were randomly assigned into primary and cross-validation groups. Body measurements were obtained via traditional anthropometrics, SBI, and DXA. Multiple regression analysis was conducted to develop mathematical equations by demographics and SBI assessed body measurements as independent variables and body adiposity (fat mass and percentage fat) as dependent variables. The validity of the prediction models was evaluated by a split sample method and Bland-Altman analysis.Results: The R2 of the prediction equations for fat mass and percentage body fat were 93.2% and 76.4% for android and 91.4% and 66.5% for gynoid, respectively. The limits of agreement for the fat mass and percentage fat were −0.06 ± 0.87 kg and −0.11% ± 1.97% for android and −0.04 ± 1.58 kg and −0.19% ± 4.27% for gynoid. Prediction values for fat mass and percentage fat were 94.6% and 88.9% for total body, 93.9% and 71.0% for trunk, and 92.4% and 64.1% for leg, respectively.Conclusions: The three-dimensional (3D) SBI produces reliable parameters that can predict android and gynoid as well as total and regional (trunk, leg) fat mass.

Novel three-dimensional image system for transurethral surgery.

Novel three-dimensional image system for transurethral surgery.

Lensless three-dimensional integral imaging using variable and time multiplexed pinhole array.

We present a multivariable coded aperture (MVCA) for lensless three-dimensional integral imaging (3D II) systems. The new configuration is based on a time multiplexing method using a variable pinholes array design. The system provides higher resolution 3D images with improved light intensity and signal to noise ratio as compared to single-pinhole system. The MVCA 3D II system configuration can be designed to achieve high light intensity for practical use as microlenslets arrays. This new configuration preserves the advantages of pinhole optics while solving the resolution limitation problem and the long exposure time of such systems. The three-dimensional images are obtained with improved resolution, signal to noise ratio, and light efficiency. This integral imaging lensless system is characterized by large depth of focus, simplicity, and low cost.

Converting optical scanning holograms of real objects to binary Fourier holograms using an iterative direct binary search algorithm.

In this paper, we present a three-dimensional holographic imaging system. The proposed approach records a complex hologram of a real object using optical scanning holography, converts the complex form to binary data, and then reconstructs the recorded hologram using a spatial light modulator (SLM). The conversion from the recorded hologram to a binary hologram is achieved using a direct binary search algorithm. We present experimental results that verify the efficacy of our approach. To the best of our knowledge, this is the first time that a hologram of a real object has been reconstructed using a binary SLM.

Test measurements and evaluations of industrial three-dimensional high-penetration tomography

The image of the current non-destructive testing system using a high energy accelerator is limited to conventional two-dimensional metaphysical information. Requirements for the present manufacturing industry are growing rapidly and include quantitative measurements, high-density component model extraction, reverse process development and precision inspection to meet the needs for the verification of manufactured goods. Therefore, industrial three-dimensional high-penetration tomography has emerged as the most promising method. In this study, in order to evaluate the applicability of a MeV-level high-energy accelerator, we developed a three-dimensional tomography system using a 450 kV X-ray generator. Evaluation of the three-dimensional tomography image is based on measurements of the penetration and the image resolution for high-energy X-rays.

頸部頸動脈狭窄性病変外科的治療での超音波診断─ 3D超音波画像とNavigation systemの応用 ─

頸部頸動脈狭窄性病変外科的治療での超音波診断─ 3D超音波画像とNavigation systemの応用 ─

Postural spinal balance defined by net intersegmental moments: Results of a biomechanical approach and experimental errors measurement.

To describe initial results and experimental error measurement of a protocol analyzing Human posture through sagittal intersegmental moments. Postural analysis has been recently improved by development of three-dimensional radiographic imaging systems. However, in various situations such as global sagittal anterior malalignment interpretation of radiographs may not represent the real alignment of the subject. The aim of this study was to present initial results of a 3D biomechanical protocol. This protocol is obtained in a free standing position and characterizes postural balance by measurement of sagittal intersegmental net moments. After elaboration of a specific marker-set, 4 successive recordings were done on two volunteers by three different operators during three sessions in order to evaluate the experimental error measurement. A supplementary acquisition in a "radiographic" posture was also obtained. Once the data acquired, joint center, length, anatomical frame and the center of mass of each body segment was calculated and a mass affected. Sagittal net intersegmental moments were computed in an ascending manner from ground reaction forces at the ankles, knees, hips and the lumbo-sacral and thoraco-lumbar spinal junctions. Cervico-thoracic net intersegmental moment was calculated in a descending manner. Based on average recordings, clinical interpretation of net intersegmental moments (in N.m) showed a dorsal flexion on the ankles (8.6 N.m), a flexion on the knees (7.5 N.m) and an extension on the hips (8.5 N.m). On the spinal junctions, it was flexion moments: 0.34 N.m on the cervico-thoracic; 6.7 N.m on the thoraco-lumbar and 0.65 N.m on the lumbo-sacral. Evaluation of experimental error measurement showed a small inter-trial error (intrinsic variability), with higher inter-session and inter-therapist errors but without important variation between them. For one volunteer the "radiographic" posture was associated to significant changes compared to the free standing position. These initial results confirm the technical feasibility of the protocol. The low intrinsic error and the small differences between inter-session and inter-therapist errors seem to traduce postural variability over time, more than a failure of the protocol. Characterization of sagittal intersegmental net moments can have clinical applications such as evaluation of an unfused segment after a spinal arthrodesis.

Accuracy and precision of integumental linear dimensions in a three-dimensional facial imaging system

ObjectiveA recently developed facial scanning method uses three-dimensional (3D) surface imaging with a light-emitting diode. Such scanning enables surface data to be captured in high-resolution color and at relatively fast speeds. The purpose of this study was to evaluate the accuracy and precision of 3D images obtained using the Morpheus 3D® scanner (Morpheus Co., Seoul, Korea).MethodsThe sample comprised 30 subjects aged 24-34 years (mean 29.0 ± 2.5 years). To test the correlation between direct and 3D image measurements, 21 landmarks were labeled on the face of each subject. Sixteen direct measurements were obtained twice using digital calipers; the same measurements were then made on two sets of 3D facial images. The mean values of measurements obtained from both methods were compared. To investigate the precision, a comparison was made between two sets of measurements taken with each method.ResultsWhen comparing the variables from both methods, five of the 16 possible anthropometric variables were found to be significantly different. However, in 12 of the 16 cases, the mean difference was under 1 mm. The average value of the differences for all variables was 0.75 mm. Precision was high in both methods, with error magnitudes under 0.5 mm.Conclusions3D scanning images have high levels of precision and fairly good congruence with traditional anthropometry methods, with mean differences of less than 1 mm. 3D surface imaging using the Morpheus 3D® scanner is therefore a clinically acceptable method of recording facial integumental data.

Efficacy, Time, Cost and Radiation Exposure of Combined Limited Fluoroscopy with Non-fluoroscopic Three-dimensional Imaging in Paediatric Supraventricular Tachycardia Ablation – Best of Both Worlds

Objective: Catheter ablation for supraventricular tachycardias (SVTs) traditionally has utilised fluoroscopic imaging (FI). However, radiation concerns have recently contributed to the evolution of non-fluoroscopic three-dimensional imaging (3DI) systems. A few recent studies have advocated non-FI in lieu of FI. To date, there are only a few studies reporting use of limited FI with 3DI usage in children undergoing SVT ablations. This study evaluates time, efficacy, cost and safety of limited FI plus 3DI for SVT ablation in the young.Methods: Electrophysiology study (EPS) and ablation data for standard forms of SVT from October 2009 to June 2012 were reviewed. Patient radiation time, radiation dose area product (DAP), EPS time, anaesthesia duration and cost, and ablation success rates were evaluated.Results: A total of 81 patients (mean age 13.2 ± 3.4 years) underwent ablation. Type of SVT, gender, age, acute success, adverse events and recurrences were recorded post-ablation for over 2.5 years. Acute procedural success was 93.8 %. Of these, chronic sustained success was 85.5 %. As expected, limited FI plus 3DI was associated with some radiation exposure (2.47 ± 2.78 milliGray-m2) but less than historically associated with paediatric tachycardia ablations.Conclusion: A conscious awareness to use limited FI combined with 3DI is associated with excellent long-term success, lack of complications and marked decrease in radiation exposure. Although 3DI-only has some appeal, use of combined limited radiation is associated with some advantages overall. Potential adverse effects of limited radiation need to be weighed in when deciding which imaging or combination to use.

Laser radar invariant spatial chromatic image descriptor

Laser radar (LADAR) is a three-dimensional (3-D) imaging system which provides very high-resolution 3-D images and is used for automatic recognition of 3-D targets. In order to achieve a high recognition ability for this system, a new LADAR image descriptor is proposed. This descriptor extracts features from the LADAR images by using special chromatic processors called invariant half-height overlapping triangular processors. The descriptor developed has a high discrimination capability and is robust to the effects that disturb LADAR images. The performance of the proposed LADAR descriptor is evaluated using simulated and real LADAR images. The results show the robustness of the proposed descriptor in the presence of noise, low resolution, view change, rotation, translation, and scaling effects. The results also show the high discrimination capability for the new descriptor over the traditional techniques such as invariant moments descriptor, which is used to benchmark the simulation and the experimental results.

High-definition resolution three-dimensional imaging systems in laparoscopic radical prostatectomy: randomized comparative study with high-definition resolution two-dimensional systems.

Three-dimensional (3D) imaging systems have been introduced worldwide for surgical instrumentation. A difficulty of laparoscopic surgery involves converting two-dimensional (2D) images into 3D images and depth perception rearrangement. 3D imaging may remove the need for depth perception rearrangement and therefore have clinical benefits. We conducted a multicenter, open-label, randomized trial to compare the surgical outcome of 3D-high-definition (HD) resolution and 2D-HD imaging in laparoscopic radical prostatectomy (LRP), in order to determine whether an LRP under HD resolution 3D imaging is superior to that under HD resolution 2D imaging in perioperative outcome, feasibility, and fatigue. One-hundred twenty-two patients were randomly assigned to a 2D or 3D group. The primary outcome was time to perform vesicourethral anastomosis (VUA), which is technically demanding and may include a number of technical difficulties considered in laparoscopic surgeries. VUA time was not significantly shorter in the 3D group (26.7 min, mean) compared with the 2D group (30.1 min, mean) (p = 0.11, Student's t test). However, experienced surgeons and 3D-HD imaging were independent predictors for shorter VUA times (p = 0.000, p = 0.014, multivariate logistic regression analysis). Total pneumoperitoneum time was not different. No conversion case from 3D to 2D or LRP to open RP was observed. Fatigue was evaluated by a simulation sickness questionnaire and critical flicker frequency. Results were not different between the two groups. Subjective feasibility and satisfaction scores were significantly higher in the 3D group. Using a 3D imaging system in LRP may have only limited advantages in decreasing operation times over 2D imaging systems. However, the 3D system increased surgical feasibility and decreased surgeons' effort levels without inducing significant fatigue.

Application of three-dimensional laparoscopic system in obturator lymph node dissection of progressive rectal cancer

To compare the handling and efficacy between three-dimensional(3D) imaging system and two-dimensional(2D) imaging system for laparoscopic surgery of rectal cancer deep obturator lymph node dissection. Clinical data of 36 patients who underwent rectal cancer resection and obturator lymph node dissection with 3D or 2D imaging system from January 2013 to May 2014 in our department were retrospectively analyzed. There were 16 cases and 20 cases in 3D group and 2D group respectively. Completion time of obturator lymph node dissection, total operation time, total number of lymph node dissected, number of wrong grasping (more than twice for correct positioning in the same site) times and blood loss during obturator lymph node dissection were compared between two groups. The laparoscopic rectal cancer resections were successfully completed without laparotomy in both groups. The completion time of obturator lymph node dissection was (23.5 ± 2.5) min and (25.0 ± 3.0) min respectively (P<0.05); the number of wrong grasping was 5.0 ± 2.0 and 6.0 ± 4.0(P<0.01); the blood loss during obturator lymph node dissection was (15.5 ± 1.5) ml and (17.5 ± 2.5) ml (P<0.01). The differences were all statistically significant. The total operation time of 3D and 2D group was (206.0 ± 26.0) min and (222.5 ± 27.5) min (P<0.05); the total number of lymph node dissected was 24 ± 6 and 21 ± 9 (P<0.05). The differences were statistically significant as well. Six cases in 3D group and 11 cases in 2D group were followed up for 1 year and there was no tumor recurrence or death case. 3D laparoscopic technique has more obvious advantages as compared with 2D laparoscopic system in rectal cancer deep obturator lymph node dissection, so it is worthy to spread.

An absolute phase to world coordinates method for the defocusing structured light shape measurement system

This paper proposes a flexible calibration method for the defocusing structured light three-dimensional (3D) imaging system. Neither a high accuracy translation stage nor the parameters of the projector is required. Therefore the method is more flexible in many practical applications. World coordinates for calibration are obtained based on the method of coordinates from known plane. The monotonic nonlinear relationships between the absolute phase and each world coordinate have been investigated. Different from other methods, in our method, the 3D shape is directly recovered by the absolute phase to world coordinates method. Experimental results show that, when polynomial curve fitting methods are used, the root-mean-squared (RMS) error for the flat plate reconstruction is less than 0.12mm, and the measurement error of 3D points is less than −0.34%. Furthermore, when comparing the measurement results of our method with the method of coordinates from known plane based on camera calibration, the relative error is less than −0.05%. Therefore, camera calibration is considered as the major error source.