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  1. MRI Volume Fusion Based on 3D Shearlet Decompositions.

    Duan, Chang; Wang, Shuai; Wang, Xue Gang; Huang, Qi Hong

    2014-01-01

    Nowadays many MRI scans can give 3D volume data with different contrasts, but the observers may want to view various contrasts in the same 3D volume. The conventional 2D medical fusion methods can only fuse the 3D volume data layer by layer, which may lead to the loss of interframe correlative information. In this paper, a novel 3D medical volume fusion method based on 3D band limited shearlet transform (3D BLST) is proposed. And this method is evaluated upon MRI T2* and quantitative susceptibility mapping data of 4 human brains. Both the perspective impression and the quality indices indicate that the proposed method has a better performance than conventional 2D wavelet, DT CWT, and 3D wavelet, DT CWT based fusion methods. PMID:24817880

  2. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    Buhl, Sune K.; Duun-Christensen, Anne Katrine; Kristensen, Brian H.;

    2010-01-01

    undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom......Background. Magnetic Resonance Imaging (MRI) is often used in modern day radiotherapy (RT) due to superior soft tissue contrast. However, treatment planning based solely on MRI is restricted due to e. g. the limitations of conducting online patient setup verification using MRI as reference. In this...... study 3D/3D MRI-Cone Beam CT (CBCT) automatching for online patient setup verification was investigated. Material and methods. Initially, a multi-modality phantom was constructed and used for a quantitative comparison of CT-CBCT and MRI-CBCT automatching. Following the phantom experiment three patients...

  3. Validation of SPAMM tagged MRI based measurement of 3D soft tissue deformation

    K.M. Moerman; A.M.J. Sprengers; C.K. Simms; R.M. Lamerichs; J. Stoker; A.J. Nederveen

    2011-01-01

    This study presents and validates a novel (non-ECG-triggered) MRI sequence based on spatial modulation of the magnetization (SPAMM) to noninvasively measure 3D (quasistatic) soft tissue deformations using only six acquisitions (three static and three indentations). In the current SPAMM tagged MRI ap

  4. Validation of SPAMM Tagged MRI Based Measurement of 3D Soft Tissue Deformation

    Kevin M. Moerman; Sprengers, Andre M. J.; Ciaran K. Simms; Lamerichs, Rolf M.; Stoker, Jaap; Aart J. Nederveen

    2016-01-01

    This study presents and validates a novel (non-ECG-triggered) MRI sequence based on SPAtial Modulation of the Magnetization (SPAMM) to non-invasively measure 3D (quasi-static) soft tissue deformations using only six acquisitions (three static and three indentations). In current SPAMM tagged MRI approaches data is typically constructed from many repeated motion cycles. This has so far restricted its application to the measurement of highly repeatable and periodic movements (e.g. cardiac deform...

  5. Validation of SPAMM Tagged MRI Based Measurement of 3D Soft Tissue Deformation

    Moerman, Kevin M; Simms, Ciaran K; Lamerichs, Rolf M; Stoker, Jaap; Nederveen, Aart J

    2016-01-01

    This study presents and validates a novel (non-ECG-triggered) MRI sequence based on SPAtial Modulation of the Magnetization (SPAMM) to non-invasively measure 3D (quasi-static) soft tissue deformations using only six acquisitions (three static and three indentations). In current SPAMM tagged MRI approaches data is typically constructed from many repeated motion cycles. This has so far restricted its application to the measurement of highly repeatable and periodic movements (e.g. cardiac deformation). In biomechanical applications where soft tissue deformation is artificially induced, often by indentation, significant repeatability constraints exist and, for clinical applications, discomfort and health issues generally preclude a large number of repetitions.

  6. Variable density sampling based on physically plausible gradient waveform. Application to 3D MRI angiography

    Chauffert, Nicolas; Boucher, Marianne; Mériaux, Sébastien; CIUCIU, Philippe

    2015-01-01

    Performing k-space variable density sampling is a popular way of reducing scanning time in Magnetic Resonance Imaging (MRI). Unfortunately, given a sampling trajectory, it is not clear how to traverse it using gradient waveforms. In this paper, we actually show that existing methods [1, 2] can yield large traversal time if the trajectory contains high curvature areas. Therefore, we consider here a new method for gradient waveform design which is based on the projection of unrealistic initial trajectory onto the set of hardware constraints. Next, we show on realistic simulations that this algorithm allows implementing variable density trajectories resulting from the piecewise linear solution of the Travelling Salesman Problem in a reasonable time. Finally, we demonstrate the application of this approach to 2D MRI reconstruction and 3D angiography in the mouse brain.

  7. A novel Hessian based algorithm for rat kidney glomerulus detection in 3D MRI

    Zhang, Min; Wu, Teresa; Bennett, Kevin M.

    2015-03-01

    The glomeruli of the kidney perform the key role of blood filtration and the number of glomeruli in a kidney is correlated with susceptibility to chronic kidney disease and chronic cardiovascular disease. This motivates the development of new technology using magnetic resonance imaging (MRI) to measure the number of glomeruli and nephrons in vivo. However, there is currently a lack of computationally efficient techniques to perform fast, reliable and accurate counts of glomeruli in MR images due to the issues inherent in MRI, such as acquisition noise, partial volume effects (the mixture of several tissue signals in a voxel) and bias field (spatial intensity inhomogeneity). Such challenges are particularly severe because the glomeruli are very small, (in our case, a MRI image is ~16 million voxels, each glomerulus is in the size of 8~20 voxels), and the number of glomeruli is very large. To address this, we have developed an efficient Hessian based Difference of Gaussians (HDoG) detector to identify the glomeruli on 3D rat MR images. The image is first smoothed via DoG followed by the Hessian process to pre-segment and delineate the boundary of the glomerulus candidates. This then provides a basis to extract regional features used in an unsupervised clustering algorithm, completing segmentation by removing the false identifications occurred in the pre-segmentation. The experimental results show that Hessian based DoG has the potential to automatically detect glomeruli,from MRI in 3D, enabling new measurements of renal microstructure and pathology in preclinical and clinical studies.

  8. MRI-based aortic blood flow model in 3D ballistocardiography.

    Lejeune, L; Prisk, G K; Nonclercq, A; Migeotte, P-F

    2015-08-01

    Ballistocardiography (BCG) is a non-invasive technique which measures the acceleration of a body induced by cardiovascular activity, namely the force exerted by the beating heart. A one dimensional aortic flow model based on the transmission lines theory is developped and applied to the simulation of three dimensional BCG. A four-element Windkessel model is used to generate the pressure-wave. Using transverse MRI slices of a human subject, a reconstruction of the aorta allows the extraction of parameters used to relate the local change in mass of the 1D flow model to 3D acceleration BCG. Simulated BCG curves are then compared qualitatively with the ensemble average curves of the same subject recorded in sustained microgravity. Confirming previous studies, the main features of the y-axis are well simulated. The simulated z-axis, never attempted before, shows important similarities. The simulated x-axis is less faithful and suggests the presence of reflections. PMID:26737946

  9. Motion corrected LV quantification based on 3D modelling for improved functional assessment in cardiac MRI

    Liew, Y. M.; McLaughlin, R. A.; Chan, B. T.; Aziz, Y. F. Abdul; Chee, K. H.; Ung, N. M.; Tan, L. K.; Lai, K. W.; Ng, S.; Lim, E.

    2015-04-01

    Cine MRI is a clinical reference standard for the quantitative assessment of cardiac function, but reproducibility is confounded by motion artefacts. We explore the feasibility of a motion corrected 3D left ventricle (LV) quantification method, incorporating multislice image registration into the 3D model reconstruction, to improve reproducibility of 3D LV functional quantification. Multi-breath-hold short-axis and radial long-axis images were acquired from 10 patients and 10 healthy subjects. The proposed framework reduced misalignment between slices to subpixel accuracy (2.88 to 1.21 mm), and improved interstudy reproducibility for 5 important clinical functional measures, i.e. end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and 3D-sphericity index, as reflected in a reduction in the sample size required to detect statistically significant cardiac changes: a reduction of 21-66%. Our investigation on the optimum registration parameters, including both cardiac time frames and number of long-axis (LA) slices, suggested that a single time frame is adequate for motion correction whereas integrating more LA slices can improve registration and model reconstruction accuracy for improved functional quantification especially on datasets with severe motion artefacts.

  10. MRI Sequence Images Compression Method Based on Improved 3D SPIHT%基于改进3D SPIHT的MRI序列图像压缩方法

    蒋行国; 李丹; 陈真诚

    2013-01-01

    目的 研究一种有效的MRI序列图像压缩方法.方法 以2组不同数量、不同层厚的MRI序列图像为例,针对3D SPIHT算法运算复杂度,在对D型、L型表项重复判断的不足上,提出了一种改进的3DSPIHT方法;同时,根据MRI序列图像的相关性特点,提出了分组编/解码的方法,结合3D小波变换和应用改进的3D SPIHT方法,实现了MRI序列图像压缩.结果 分组结合改进3D SPIHT方法与2DSPIHT,3D SPIHT相比,能够得到较好重构图像,同时,峰值信噪比(PSNR)提高了1~8 dB左右.结论 在相同码率下,分组结合改进3D SPIHT的方法提高了PSNR和图像恢复质量,可以更好地解决大量MRI序列图像存储与传输问题.%Objective To propose an effective MRI sequence image compression method for solving the storage and transmission problem of large amounts of MRI sequence images. Methods Aimed at alleviating the complexity of computation of 3D Set Partitioning in Hierarchical Trees( SPIHT) algorithm and the deficiency that D or L type table were judged repeatedly, an improved 3 D SPIHT method was presented and two groups of MRI sequence images with different numbers and slice thickness were taken as examples. At the same time, according to the correlation characteristics of MRI sequence images, a method that images were divided into groups and then coded/decoded was put forward in this paper. It combined with 3D wavelet transform and the improved 3D SPIHT method, the MRI sequence image compression was achieved. Results Comparing with the 2D SPIHT and 3D SPIHT methods, the grouping combined with the improved 3D SPIHT method could obtain better reconstructed images and Peak Signal Noise Ratio (PSNR) could be improved by 1 ~ 8 dB as well. Conclusion At the same bit rate, PSNR and image quality of recovery can be improved by the grouping combined with the improved 3D SPIHT method and the storage and transmission problem of large amounts of MRI sequence images can be solved.

  11. 3D MRI-based predictive control of a ferromagnetic microrobot navigating in blood vessels

    Belharet, Karim; Folio, David; Ferreira, Antoine

    2010-01-01

    This paper presents an endovascular navigation of a ferromagneticmicrodevice using a MRI-based predictive control. The concept wasstudied for future development of microrobot designed to performminimally invasive interventions in remote sites accessible throughthe human cardiovascular system. A system software architecture ispresented illustrating the different software modules to allow 3Dnavigation of a microdevice in blood vessels, namely: (i) vesselpath extraction, (ii) magnetic gradient s...

  12. 3D-Dixon MRI based volumetry of peri- and epicardial fat.

    Homsi, Rami; Meier-Schroers, Michael; Gieseke, Jürgen; Dabir, Darius; Luetkens, Julian A; Kuetting, Daniel L; Naehle, Claas P; Marx, Christian; Schild, Hans H; Thomas, Daniel K; Sprinkart, Alois M

    2016-02-01

    There is growing evidence that pericardial and epicardial fat volume (PFV, EFV) are associated with cardiovascular risk. We evaluated a novel method for accurate measurement of PFV and EFV using a 3D-Dixon based cardiac magnetic resonance (CMR) approach. An electrocardiography triggered and respiratory navigator gated 3D-gradient echo pulse sequence was used for cardiac Dixon imaging. Based on this sequence, voxels predominantly containing fat were identified and added up for volumetry. After accuracy assessment in phantoms, consisting of muscle tissue and seven different fat samples (50-200 ml), the sequence was acquired in 34 healthy volunteers (22 male, BMI range 14-42 kg/m(2), age range 21-79 years) at 1.5 T. Analysis was performed independently by two readers who draw two 3D-regions of interest, one for EFV and one for PFV. Additionally, EFV and PFV were compared between overweighted and non-overweighted subjects. The phantom study showed an excellent agreement of measured and true fat volumes (maximum difference = 6 %, linear correlation coefficient R = 1.00). PFV over all volunteers was 158.0 ± 126.4 ml and EFV was 77.0 ± 55.3 ml. PFV and EFV were highly correlated (R = 0.96). Inter-reader agreement was good with a mean difference of 0.2 ± 5.6 and 4.5 ± 4.2 ml for PFV/EFV, (R > 0.99, each). EFV and PFV differed significantly between subjects with BMI > 25 kg/m(2) and BMI Dixon based method allows accurate measurement of cardiac fat volumes. It provides a valuable tool for cardiovascular risk stratification by CMR. PMID:26424492

  13. Clinical evaluation of 3D/3D MRI-CBCT automatching on brain tumors for online patient setup verification - A step towards MRI-based treatment planning

    Buhl, S.K.; Duun-Christensen, Anne Katrine; Kristensen, B.H.;

    2010-01-01

    undergoing postoperative radiotherapy for malignant brain tumors received a weekly CBCT. In total 18 scans was matched with both CT and MRI as reference. The CBCT scans were acquired using a Clinac iX 2300 linear accelerator (Varian Medical Systems) with an On-Board Imager (OBI). Results. For the phantom...

  14. Segmentation of Brain MRI Using SOM-FCM-Based Method and 3D Statistical Descriptors

    Andrés Ortiz

    2013-01-01

    Full Text Available Current medical imaging systems provide excellent spatial resolution, high tissue contrast, and up to 65535 intensity levels. Thus, image processing techniques which aim to exploit the information contained in the images are necessary for using these images in computer-aided diagnosis (CAD systems. Image segmentation may be defined as the process of parcelling the image to delimit different neuroanatomical tissues present on the brain. In this paper we propose a segmentation technique using 3D statistical features extracted from the volume image. In addition, the presented method is based on unsupervised vector quantization and fuzzy clustering techniques and does not use any a priori information. The resulting fuzzy segmentation method addresses the problem of partial volume effect (PVE and has been assessed using real brain images from the Internet Brain Image Repository (IBSR.

  15. MRI-based 3D pelvic autonomous innervation: a first step towards image-guided pelvic surgery

    To analyse pelvic autonomous innervation with magnetic resonance imaging (MRI) in comparison with anatomical macroscopic dissection on cadavers. Pelvic MRI was performed in eight adult human cadavers (five men and three women) using a total of four sequences each: T1, T1 fat saturation, T2, diffusion weighed. Images were analysed with segmentation software in order to extract nervous tissue. Key height points of the pelvis autonomous innervation were located in every specimen. Standardised pelvis dissections were then performed. Distances between the same key points and the three anatomical references forming a coordinate system were measured on MRIs and dissections. Concordance (Lin's concordance correlation coefficient) between MRI and dissection was calculated. MRI acquisition allowed an adequate visualization of the autonomous innervation. Comparison between 3D MRI images and dissection showed concordant pictures. The statistical analysis showed a mean difference of less than 1 cm between MRI and dissection measures and a correct concordance correlation coefficient on at least two coordinates for each point. Our acquisition and post-processing method demonstrated that MRI is suitable for detection of autonomous pelvic innervations and can offer a preoperative nerve cartography. (orig.)

  16. MRI-based 3D pelvic autonomous innervation: a first step towards image-guided pelvic surgery

    Bertrand, M.M. [University Montpellier I, Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nimes, Montpellier (France); Macri, F.; Beregi, J.P. [Nimes University Hospital, University Montpellier 1, Radiology Department, Nimes (France); Mazars, R.; Prudhomme, M. [University Montpellier I, Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nimes, Montpellier (France); Nimes University Hospital, University Montpellier 1, Digestive Surgery Department, Nimes (France); Droupy, S. [Nimes University Hospital, University Montpellier 1, Urology-Andrology Department, Nimes (France)

    2014-08-15

    To analyse pelvic autonomous innervation with magnetic resonance imaging (MRI) in comparison with anatomical macroscopic dissection on cadavers. Pelvic MRI was performed in eight adult human cadavers (five men and three women) using a total of four sequences each: T1, T1 fat saturation, T2, diffusion weighed. Images were analysed with segmentation software in order to extract nervous tissue. Key height points of the pelvis autonomous innervation were located in every specimen. Standardised pelvis dissections were then performed. Distances between the same key points and the three anatomical references forming a coordinate system were measured on MRIs and dissections. Concordance (Lin's concordance correlation coefficient) between MRI and dissection was calculated. MRI acquisition allowed an adequate visualization of the autonomous innervation. Comparison between 3D MRI images and dissection showed concordant pictures. The statistical analysis showed a mean difference of less than 1 cm between MRI and dissection measures and a correct concordance correlation coefficient on at least two coordinates for each point. Our acquisition and post-processing method demonstrated that MRI is suitable for detection of autonomous pelvic innervations and can offer a preoperative nerve cartography. (orig.)

  17. MRI-based Preplanning Using CT and MRI Data Fusion in Patients With Cervical Cancer Treated With 3D-based Brachytherapy: Feasibility and Accuracy Study

    Dolezel, Martin, E-mail: dolezelm@email.cz [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First Faculty of Medicine, Charles University, Prague (Czech Republic); Odrazka, Karel [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); First Faculty of Medicine, Charles University, Prague (Czech Republic); Zizka, Jan [Department of Radiology, Charles University Teaching Hospital, Hradec Kralove (Czech Republic); Vanasek, Jaroslav; Kohlova, Tereza; Kroulik, Tomas [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Spitzer, Dusan; Ryska, Pavel [Department of Radiology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Tichy, Michal; Kostal, Milan [Department of Gynaecology, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic); Jalcova, Lubica [Oncology Centre, Multiscan and Pardubice Regional Hospital, Pardubice (Czech Republic)

    2012-09-01

    Purpose: Magnetic resonance imaging (MRI)-assisted radiation treatment planning enables enhanced target contouring. The purpose of this study is to analyze the feasibility and accuracy of computed tomography (CT) and MRI data fusion for MRI-based treatment planning in an institution where an MRI scanner is not available in the radiotherapy department. Methods and Materials: The registration inaccuracy of applicators and soft tissue was assessed in 42 applications with CT/MRI data fusion. The absolute positional difference of the center of the applicators was measured in four different planes from the top of the tandem to the cervix. Any inaccuracy of registration of soft tissue in relation to the position of applicators was determined and dose-volume parameters for MRI preplans and for CT/MRI fusion plans with or without target and organs at risk (OAR) adaptation were evaluated. Results: We performed 6,132 measurements in 42 CT/MRI image fusions. Median absolute difference of the center of tandem on CT and MRI was 1.1 mm. Median distance between the center of the right ovoid on CT and MRI was 1.7 and 1.9 mm in the laterolateral and anteroposterior direction, respectively. Corresponding values for the left ovoid were 1.6 and 1.8 mm. Rotation of applicators was 3.1 Degree-Sign . Median absolute difference in position of applicators in relation to soft tissue was 1.93, 1.50, 1.05, and 0.84 mm in the respective transverse planes, and 1.17, 1.28, 1.27, and 1.17 mm in selected angular directions. The dosimetric parameters for organs at risk on CT/MRI fusion plans without OAR adaptation were significantly impaired whereas the target coverage was not influenced. Planning without target adaptation led to overdosing of the target volume, especially high-risk clinical target volume - D{sub 90} 88.2 vs. 83.1 (p < 0.05). Conclusions: MRI-based preplanning with consecutive CT/MRI data fusion can be safe and feasible, with an acceptable inaccuracy of soft tissue registration.

  18. Multi-feature-based plaque characterization in ex vivo MRI trained by registration to 3D histology

    Engelen, Arna van; Niessen, Wiro J.; Klein, Stefan; Groen, Harald C.; Verhagen, Hence J.M.; Wentzel, Jolanda J.; Lugt, Aad van der; de Bruijne, Marleen

    2012-01-01

    voxelwise classification on different combinations of features, we evaluated their relative importance. To establish whether training by 3D registration yields different results than training by 2D registration, we determined plaque composition using (1) a 2D slice-based registration approach for three...

  19. A new method to explore the spectral impact of the piriform fossae on the singing voice:Benchmarking using MRI-based 3D-printed vocal tracts

    Bertrand Delvaux; David Howard

    2014-01-01

    The piriform fossae are the 2 pear-shaped cavities lateral to the laryngeal vestibule at the lower end of the vocal tract. They act acoustically as side-branches to the main tract, resulting in a spectral zero in the output of the human voice. This study investigates their spectral role by comparing numerical and experimental results of MRI-based 3D printed Vocal Tracts, for which a new experimental method (based on room acoustics) is introduced. The findings support results in the literature...

  20. 3-D MRI for lumbar degenerative diseases

    Three-dimensional (3-D) magnetic resonance (MR) images obtained from 10 patients with lumbar degenerative diseases were retrospectively reviewed to determine how far 3-D MR imaging is capable of demonstrating nerve roots. In 8 of the 10 patients, the area up to the dorsal root ganglion was visualized on 3-D MR images. Thus, it is capable of detecting a wide area of nerve roots, thereby allowing the determination of running of nerve root, and size and location of dorsal root ganglion. In delineating the area from the dural canal to root cyst, 3-D MR imaging was equal to conventional myelography. The former was superior to the latter in detecting the positional relation between the degenerative intervertebral disc and the nerve root, and herniation-compressed root cyst. In 3 of 9 patients who presented with root symptoms, disturbed nerve roots were of high signal on 3-D MR images. This may suggest that it has the potential for selectively detecting root nerves associated with clinical manifestations. (N.K.)

  1. A new method to explore the spectral impact of the piriform fossae on the singing voice: benchmarking using MRI-based 3D-printed vocal tracts.

    Delvaux, Bertrand; Howard, David

    2014-01-01

    The piriform fossae are the 2 pear-shaped cavities lateral to the laryngeal vestibule at the lower end of the vocal tract. They act acoustically as side-branches to the main tract, resulting in a spectral zero in the output of the human voice. This study investigates their spectral role by comparing numerical and experimental results of MRI-based 3D printed Vocal Tracts, for which a new experimental method (based on room acoustics) is introduced. The findings support results in the literature: the piriform fossae create a spectral trough in the region 4-5 kHz and act as formants repellents. Moreover, this study extends those results by demonstrating numerically and perceptually the impact of having large piriform fossae on the sung output. PMID:25048199

  2. A new method to explore the spectral impact of the piriform fossae on the singing voice: benchmarking using MRI-based 3D-printed vocal tracts.

    Bertrand Delvaux

    Full Text Available The piriform fossae are the 2 pear-shaped cavities lateral to the laryngeal vestibule at the lower end of the vocal tract. They act acoustically as side-branches to the main tract, resulting in a spectral zero in the output of the human voice. This study investigates their spectral role by comparing numerical and experimental results of MRI-based 3D printed Vocal Tracts, for which a new experimental method (based on room acoustics is introduced. The findings support results in the literature: the piriform fossae create a spectral trough in the region 4-5 kHz and act as formants repellents. Moreover, this study extends those results by demonstrating numerically and perceptually the impact of having large piriform fossae on the sung output.

  3. Velocity Measurement in Carotid Artery: Quantitative Comparison of Time-Resolved 3D Phase-Contrast MRI and Image-based Computational Fluid Dynamics

    Sarrami-Foroushani

    2015-10-01

    Full Text Available Background Understanding hemodynamic environment in vessels is important for realizing the mechanisms leading to vascular pathologies. Objectives Three-dimensional velocity vector field in carotid bifurcation is visualized using TR 3D phase-contrast magnetic resonance imaging (TR 3D PC MRI and computational fluid dynamics (CFD. This study aimed to present a qualitative and quantitative comparison of the velocity vector field obtained by each technique. Subjects and Methods MR imaging was performed on a 30-year old male normal subject. TR 3D PC MRI was performed on a 3 T scanner to measure velocity in carotid bifurcation. 3D anatomical model for CFD was created using images obtained from time-of-flight MR angiography. Velocity vector field in carotid bifurcation was predicted using CFD and PC MRI techniques. A statistical analysis was performed to assess the agreement between the two methods. Results Although the main flow patterns were the same for the both techniques, CFD showed a greater resolution in mapping the secondary and circulating flows. Overall root mean square (RMS errors for all the corresponding data points in PC MRI and CFD were 14.27% in peak systole and 12.91% in end diastole relative to maximum velocity measured at each cardiac phase. Bland-Altman plots showed a very good agreement between the two techniques. However, this study was not aimed to validate any of methods, instead, the consistency was assessed to accentuate the similarities and differences between Time-resolved PC MRI and CFD. Conclusion Both techniques provided quantitatively consistent results of in vivo velocity vector fields in right internal carotid artery (RCA. PC MRI represented a good estimation of main flow patterns inside the vasculature, which seems to be acceptable for clinical use. However, limitations of each technique should be considered while interpreting results.

  4. Automated 3D Brain Tumor Edema Segmentation in FLAIR MRI

    Dvořák, P.; Bartušek, Karel

    Vol. S1. Berlin : Springer-Verlag, 2013, s. 489. ISSN 1352-8661. [ESMRMB 2013. Congress. Tolouse (FR), 03.10.2013-05.10.2013] Institutional support: RVO:68081731 Keywords : Automated 3D * brain tumor edema segmentation * FLAIR MRI Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  5. Comparison of 3D MRI with high sampling efficiency and 2D multiplanar MRI for contouring in cervix cancer brachytherapy

    MRI sequences with short scanning times may improve accessibility of image guided adaptive brachytherapy (IGABT) of cervix cancer. We assessed the value of 3D MRI for contouring by comparing it to 2D multi-planar MRI. In 14 patients, 2D and 3D pelvic MRI were obtained at IGABT. High risk clinical target volume (HR CTV) was delineated by 2 experienced radiation oncologists, using the conventional (2D MRI-based) and test (3D MRI-based) approach. The value of 3D MRI for contouring was evaluated by using the inter-approach and inter-observer analysis of volumetric and topographic contouring uncertainties. To assess the magnitude of deviation from the conventional approach when using the test approach, the inter-approach analysis of contouring uncertainties was carried out for both observers. In addition, to assess reliability of 3D MRI for contouring, the impact of contouring approach on the magnitude of inter-observer delineation uncertainties was analysed. No approach- or observer - specific differences in HR CTV sizes, volume overlap, or distances between contours were identified. When averaged over all delineated slices, the distances between contours in the inter-approach analysis were 2.6 (Standard deviation (SD) 0.4) mm and 2.8 (0.7) mm for observers 1 and 2, respectively. The magnitude of topographic and volumetric inter-observer contouring uncertainties, as obtained on the conventional approach, was maintained on the test approach. This variation was comparable to the inter-approach uncertainties with distances between contours of 3.1 (SD 0.8) and 3.0 (SD 0.7) mm on conventional and test approach, respectively. Variation was most pronounced at caudal HR CTV levels in both approaches and observers. 3D MRI could potentially replace multiplanar 2D MRI in cervix cancer IGABT, shortening the overall MRI scanning time and facilitating the contouring process, thus making this treatment method more widely employed

  6. Patient-Specific Carotid Plaque Progression Simulation Using 3D Meshless Generalized Finite Difference Models with Fluid-Structure Interactions Based on Serial In Vivo MRI Data.

    Yang, Chun; Tang, Dalin; Atluri, Satya

    2011-01-01

    Previously, we introduced a computational procedure based on three-dimensional meshless generalized finite difference (MGFD) method and serial magnetic resonance imaging (MRI) data to quantify patient-specific carotid atherosclerotic plaque growth functions and simulate plaque progression. Structure-only models were used in our previous report. In this paper, fluid-stricture interaction (FSI) was added to improve on prediction accuracy. One participating patient was scanned three times (T1, T2, and T3, at intervals of about 18 months) to obtain plaque progression data. Blood flow was assumed to laminar, Newtonian, viscous and incompressible. The Navier-Stokes equations with arbitrary Lagrangian-Eulerian (ALE) formulation were used as the governing equations. Plaque material was assumed to be uniform, homogeneous, isotropic, linear, and nearly incompressible. The linear elastic model was used. The 3D FSI plaque model was discretized and solved using a meshless generalized finite difference (GFD) method. Growth functions with a) morphology alone; b) morphology and plaque wall stress (PWS); morphology and flow shear stress (FSS), and d) morphology, PWS and FSS were introduced to predict future plaque growth based on previous time point data. Starting from the T2 plaque geometry, plaque progression was simulated by solving the FSI model and adjusting plaque geometry using plaque growth functions iteratively until T3 is reached. Numerically simulated plaque progression agreed very well with the target T3 plaque geometry with errors ranging from 8.62%, 7.22%, 5.77% and 4.39%, with the growth function including morphology, plaque wall stress and flow shear stress terms giving the best predictions. Adding flow shear stress term to the growth function improved the prediction error from 7.22% to 4.39%, a 40% improvement. We believe this is the first time 3D plaque progression FSI simulation based on multi-year patient-tracking data was reported. Serial MRI-based progression

  7. Intraplaque hemorrhage is associated with higher structural stresses in human atherosclerotic plaques: an in vivo MRI-based 3d fluid-structure interaction study

    Canton Gador

    2010-12-01

    Full Text Available Abstract Background Studies using medical images have shown that intraplaque hemorrhage may accelerate plaque progression and may produce a stimulus for atherosclerosis development by increasing lipid core and plaque volume and creating new destabilizing factors. Image-based 3D computational models with fluid-structure interactions (FSI will be used to perform plaque mechanical analysis and investigate possible associations between intraplaque hemorrhage and both plaque wall stress (PWS and flow shear stress (FSS. Methods In vivo MRI data of carotid plaques from 5 patients with intraplaque hemorrhage confirmed by histology were acquired. 3D multi-component FSI models were constructed for each plaque to obtain mechanical stresses. Plaque Wall Stress (PWS and Flow Shear Stress (FSS were extracted from all nodal points on the lumen surface of each plaque for analysis. Results The mean PWS value from all hemorrhage nodes of the 5 plaques combined was higher than that from non-hemorrhage nodes (75.6 versus 68.1 kPa, P = 0.0003. The mean PWS values from hemorrhage nodes for each of the 5 plaques were all significantly higher (5 out of 5 than those from non-hemorrhage nodes (P 2, P = 0.0002. However, the mean flow shear stress values from individual cases showed mixed results: only one out of five plaques showed mean FSS value from hemorrhage nodes was higher than that from non-hemorrhage nodes; three out of five plaques showed that their mean FSS values from hemorrhage nodes were lower than those from non-hemorrhage nodes; and one plaque showed that the difference had no statistical significance. Conclusion The results of this study suggested that intraplaque hemorrhage nodes were associated with higher plaque wall stresses. Compared to flow shear stress, plaque wall stress has a better correlation with plaque component feature (hemorrhage linked to plaque progression and vulnerability. With further validation, plaque stress analysis may provide

  8. Audio-visual perception of 3D cinematography: an fMRI study using condition-based and computation-based analyses.

    Ogawa, Akitoshi; Bordier, Cecile; Macaluso, Emiliano

    2013-01-01

    The use of naturalistic stimuli to probe sensory functions in the human brain is gaining increasing interest. Previous imaging studies examined brain activity associated with the processing of cinematographic material using both standard "condition-based" designs, as well as "computational" methods based on the extraction of time-varying features of the stimuli (e.g. motion). Here, we exploited both approaches to investigate the neural correlates of complex visual and auditory spatial signals in cinematography. In the first experiment, the participants watched a piece of a commercial movie presented in four blocked conditions: 3D vision with surround sounds (3D-Surround), 3D with monaural sound (3D-Mono), 2D-Surround, and 2D-Mono. In the second experiment, they watched two different segments of the movie both presented continuously in 3D-Surround. The blocked presentation served for standard condition-based analyses, while all datasets were submitted to computation-based analyses. The latter assessed where activity co-varied with visual disparity signals and the complexity of auditory multi-sources signals. The blocked analyses associated 3D viewing with the activation of the dorsal and lateral occipital cortex and superior parietal lobule, while the surround sounds activated the superior and middle temporal gyri (S/MTG). The computation-based analyses revealed the effects of absolute disparity in dorsal occipital and posterior parietal cortices and of disparity gradients in the posterior middle temporal gyrus plus the inferior frontal gyrus. The complexity of the surround sounds was associated with activity in specific sub-regions of S/MTG, even after accounting for changes of sound intensity. These results demonstrate that the processing of naturalistic audio-visual signals entails an extensive set of visual and auditory areas, and that computation-based analyses can track the contribution of complex spatial aspects characterizing such life-like stimuli. PMID

  9. Audio-visual perception of 3D cinematography: an fMRI study using condition-based and computation-based analyses.

    Akitoshi Ogawa

    Full Text Available The use of naturalistic stimuli to probe sensory functions in the human brain is gaining increasing interest. Previous imaging studies examined brain activity associated with the processing of cinematographic material using both standard "condition-based" designs, as well as "computational" methods based on the extraction of time-varying features of the stimuli (e.g. motion. Here, we exploited both approaches to investigate the neural correlates of complex visual and auditory spatial signals in cinematography. In the first experiment, the participants watched a piece of a commercial movie presented in four blocked conditions: 3D vision with surround sounds (3D-Surround, 3D with monaural sound (3D-Mono, 2D-Surround, and 2D-Mono. In the second experiment, they watched two different segments of the movie both presented continuously in 3D-Surround. The blocked presentation served for standard condition-based analyses, while all datasets were submitted to computation-based analyses. The latter assessed where activity co-varied with visual disparity signals and the complexity of auditory multi-sources signals. The blocked analyses associated 3D viewing with the activation of the dorsal and lateral occipital cortex and superior parietal lobule, while the surround sounds activated the superior and middle temporal gyri (S/MTG. The computation-based analyses revealed the effects of absolute disparity in dorsal occipital and posterior parietal cortices and of disparity gradients in the posterior middle temporal gyrus plus the inferior frontal gyrus. The complexity of the surround sounds was associated with activity in specific sub-regions of S/MTG, even after accounting for changes of sound intensity. These results demonstrate that the processing of naturalistic audio-visual signals entails an extensive set of visual and auditory areas, and that computation-based analyses can track the contribution of complex spatial aspects characterizing such life

  10. Sodium 3D COncentration MApping (COMA 3D) Using 23Na and Proton MRI

    Truong, Milton L.; Harrington, Michael G.; Schepkin, Victor D.; Chekmenev, Eduard Y.

    2014-01-01

    Functional changes of sodium 3D MRI signals were converted into millimolar concentration changes using an open-source fully automated MATLAB toolbox. These concentration changes are visualized via 3D sodium concentration maps, and they are overlaid over conventional 3D proton images to provide high-resolution co-registration for easy correlation of functional changes to anatomical regions. Nearly 5000/hour concentration maps were generated on a personal computer (ca. 2012) using 21.1 T 3D sodium MRI brain images of live rats with spatial resolution of 0.8×0.8×0.8 mm3 and imaging matrices of 60×60×60. The produced concentration maps allowed for non-invasive quantitative measurement of in vivo sodium concentration in the normal rat brain as a functional response to migraine-like conditions. The presented work can also be applied to sodium-associated changes in migraine, cancer, and other metabolic abnormalities that can be sensed by molecular imaging. The MATLAB toolbox allows for automated image analysis of the 3D images acquired on the Bruker platform and can be extended to other imaging platforms. The resulting images are presented in a form of series of 2D slices in all three dimensions in native MATLAB and PDF formats. The following is provided: (a) MATLAB source code for image processing, (b) the detailed processing procedures, (c) description of the code and all sub-routines, (d) example data sets of initial and processed data. The toolbox can be downloaded at: http://www.vuiis.vanderbilt.edu/~truongm/COMA3D/ PMID:25261742

  11. Image Reconstruction from 2D stack of MRI/CT to 3D using Shapelets

    Arathi T

    2014-12-01

    Full Text Available Image reconstruction is an active research field, due to the increasing need for geometric 3D models in movie industry, games, virtual environments and in medical fields. 3D image reconstruction aims to arrive at the 3D model of an object, from its 2D images taken at different viewing angles. Medical images are multimodal, which includes MRI, CT scan image, PET and SPECT images. Of these, MRI and CT scan images of an organ when taken, is available as a stack of 2D images, taken at different angles. This 2D stack of images is used to get a 3D view of the organ of interest, to aid doctors in easier diagnosis. Existing 3D reconstruction techniques are voxel based techniques, which tries to reconstruct the 3D view based on the intensity value stored at each voxel location. These techniques don’t make use of the shape/depth information available in the 2D image stack. In this work, a 3D reconstruction technique for MRI/CT 2D image stack, based on Shapelets has been proposed. Here, the shape/depth information available in each 2D image in the image stack is manipulated to get a 3D reconstruction, which gives a more accurate 3D view of the organ of interest. Experimental results exhibit the efficiency of this proposed technique.

  12. Noninvasive 3D pressure calculation from PC-MRI via non-iterative harmonics-based orthogonal projection: constant flow experiment.

    Negahdar, M J; Kadbi, Mo; Cha, J; Cebral, J; Amini, A

    2013-01-01

    Use of phase-contrast (PC) MRI in assessment of hemodynamics has significant clinical importance. In this paper we develop a novel approach to determination of hemodynamic pressures. 3D gradients of pressure obtained from Navier-Stokes equation are expanded into a series of orthogonal basis functions, and are subsequently projected onto an integrable subspace. Before the projection step however, a scheme is devised to eliminate the discontinuity at the vessel and image boundaries. In terms of the computation time, the proposed approach significantly improves on previous iterative methods for pressure calculations. The method has been validated using computational fluid dynamic simulations and in-vitro MRI studies of stenotic flows. PMID:24110706

  13. Crowdsourcing Based 3d Modeling

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  14. Creation of computerized 3D MRI-integrated atlases of the human basal ganglia and thalamus

    Sadikot, Abbas F; D. Louis Collins

    2011-01-01

    Functional brain imaging and neurosurgery in subcortical areas often requires visualization of brain nuclei beyond the resolution of current Magnetic Resonance Imaging (MRI) methods. We present techniques used to create: 1) a lower resolution 3D atlas, based on the Schaltenbrand and Wahren print atlas, which was integrated into a stereotactic neurosurgery planning and visualization platform (VIPER); and 2) a higher resolution 3D atlas derived from a single set of manually segmented histologic...

  15. Creation of Computerized 3D MRI-Integrated Atlases of the Human Basal Ganglia and Thalamus

    Sadikot, Abbas F; Chakravarty, M Mallar; Bertrand, Gilles; Rymar, Vladimir V.; Al-Subaie, Fahd; Collins, D. Louis

    2011-01-01

    Functional brain imaging and neurosurgery in subcortical areas often requires visualization of brain nuclei beyond the resolution of current magnetic resonance imaging (MRI) methods. We present techniques used to create: (1) a lower resolution 3D atlas, based on the Schaltenbrand and Wahren print atlas, which was integrated into a stereotactic neurosurgery planning and visualization platform (VIPER); and (2) a higher resolution 3D atlas derived from a single set of manually segmented histolog...

  16. Comparison of hemodynamics of intracranial aneurysms between MR fluid dynamics using 3D cine phase-contrast MRI and MR-based computational fluid dynamics

    Hemodynamics is thought to play a very important role in the initiation, growth, and rupture of intracranial aneurysms. The purpose of our study was to compare hemodynamics of intracranial aneurysms of MR fluid dynamics (MRFD) using 3D cine PC MR imaging (4D-Flow) at 1.5 T and MR-based computational fluid dynamics (CFD). 4D-Flow was performed for five intracranial aneurysms by a 1.5 T MR scanner. 3D TOF MR angiography was performed for geometric information. The blood flow in the aneurysms was modeled using CFD simulation based on the finite element method. We used MR angiographic data as the vascular models and MR flow information as boundary conditions in CFD. 3D velocity vector fields, 3D streamlines, shearing velocity maps, wall shear stress (WSS) distribution maps and oscillatory shear index (OSI) distribution maps were obtained by MRFD and CFD and were compared. There was a moderate to high degree of correlation in 3D velocity vector fields and a low to moderate degree of correlation in WSS of aneurysms between MRFD and CFD using regression analysis. The patterns of 3D streamlines were similar between MRFD and CFD. The small and rotating shearing velocities and higher OSI were observed at the top of the spiral flow in the aneurysms. The pattern and location of shearing velocity in MRFD and CFD were similar. The location of high oscillatory shear index obtained by MRFD was near to that obtained by CFD. MRFD and CFD of intracranial aneurysms correlated fairly well. (orig.)

  17. New method for 3D parametric visualization of contrast-enhanced pulmonary perfusion MRI data

    Three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (3D DCE-MRI) has been proposed for the assessment of regional perfusion. The aim of this work was the implementation of an algorithm for a 3D parametric visualization of lung perfusion using different cutting planes and volume rendering. Our implementation was based on 3D DCE-MRI data of the lungs of five patients and five healthy volunteers. Using the indicator dilution theory, the regional perfusion parameters, tissue blood flow, blood volume and mean transit time were calculated. Due to the required temporal resolution, the volume elements of dynamic MR data sets show a reduced spatial resolution in the z-direction. Therefore, perfusion parameter volumes were interpolated. Linear interpolation and a combination of linear and nearest-neighbor interpolation were evaluated. Additionally, ray tracing was applied for 3D visualization. The linear interpolation algorithm caused interpolation errors at the lung borders. Using the combined interpolation, visualization of perfusion information in arbitrary cutting planes and in 3D using volume rendering was possible. This facilitated the localization of perfusion deficits compared with the coronal orientated source data. The 3D visualization of perfusion parameters using a combined interpolation algorithm is feasible. Further studies are required to evaluate the additional benefit from the 3D visualization. (orig.)

  18. 4D ultrasound and 3D MRI registration of beating heart

    To realize intra-cardiac surgery without cardio-pulmonary bypass, a medical imaging technique with both high image quality and data acquisition rate that is fast enough to follow heart beat movements is required. In this research, we proposed a method that utilized the image quality of MRI and the speed of ultrasound. We developed a 4D image reconstruction method using image registration of 3D MRI and 4D ultrasound images. The registration method consists of rigid registration between 3D MRI and 3D ultrasound with the same heart beat phase, and non-rigid registration between 3D ultrasound images from different heart beat phases. Non-rigid registration was performed with B-spline based registration using variable spring model. In phantom experiment using balloon phantom, registration accuracy was less than 2 mm for total heart volume variation range of 10%. We applied our registration method on 3D MRI and 4D ultrasound images of a volunteer's beating heart data and confirmed through visual observation that heart beat pattern was well reproduced. (orig.)

  19. View-based 3-D object retrieval

    Gao, Yue

    2014-01-01

    Content-based 3-D object retrieval has attracted extensive attention recently and has applications in a variety of fields, such as, computer-aided design, tele-medicine,mobile multimedia, virtual reality, and entertainment. The development of efficient and effective content-based 3-D object retrieval techniques has enabled the use of fast 3-D reconstruction and model design. Recent technical progress, such as the development of camera technologies, has made it possible to capture the views of 3-D objects. As a result, view-based 3-D object retrieval has become an essential but challenging res

  20. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

    Horng, Annie; Stockinger, M.; Notohamiprodjo, M. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Raya, J.G. [New York University Langone Medical Center, Center for Biomedical Imaging, New York, NY (United States); Pietschmann, M. [Ludwig-Maximilians-University Hospital Munich, Department of Orthopedic Surgery, Munich (Germany); Hoehne-Hueckstaedt, U.; Glitsch, U.; Ellegast, R. [Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA), Sankt Augustin (Germany); Hering, K.G. [Miner' s Hospital, Department of Diagnostic Radiology, Dortmund (Germany); Glaser, C. [Ludwig-Maximilians-University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); RZM Zentrum, Munich (Germany)

    2015-06-01

    To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. (orig.)

  1. Topographic deformation patterns of knee cartilage after exercises with high knee flexion: an in vivo 3D MRI study using voxel-based analysis at 3T

    To implement a novel voxel-based technique to identify statistically significant local cartilage deformation and analyze in-vivo topographic knee cartilage deformation patterns using a voxel-based thickness map approach for high-flexion postures. Sagittal 3T 3D-T1w-FLASH-WE-sequences of 10 healthy knees were acquired before and immediately after loading (kneeling/squatting/heel sitting/knee bends). After cartilage segmentation, 3D-reconstruction and 3D-registration, colour-coded deformation maps were generated by voxel-based subtraction of loaded from unloaded datasets to visualize cartilage thickness changes in all knee compartments. Compression areas were found bifocal at the peripheral medial/caudolateral patella, both posterior femoral condyles and both anterior/central tibiae. Local cartilage thickening were found adjacent to the compression areas. Significant local strain ranged from +13 to -15 %. Changes were most pronounced after squatting, least after knee bends. Shape and location of deformation areas varied slightly with the loading paradigm, but followed a similar pattern consistent between different individuals. Voxel-based deformation maps identify individual in-vivo load-specific and posture-associated strain distribution in the articular cartilage. The data facilitate understanding individual knee loading properties and contribute to improve biomechanical 3 models. They lay a base to investigate the relationship between cartilage degeneration patterns in common osteoarthritis and areas at risk of cartilage wear due to mechanical loading in work-related activities. (orig.)

  2. Creation of computerized 3D MRI-integrated atlases of the human basal ganglia and thalamus

    Abbas F. Sadikot

    2011-09-01

    Full Text Available Functional brain imaging and neurosurgery in subcortical areas often requires visualization of brain nuclei beyond the resolution of current Magnetic Resonance Imaging (MRI methods. We present techniques used to create: 1 a lower resolution 3D atlas, based on the Schaltenbrand and Wahren print atlas, which was integrated into a stereotactic neurosurgery planning and visualization platform (VIPER; and 2 a higher resolution 3D atlas derived from a single set of manually segmented histological slices containing nuclei of the basal ganglia, thalamus, basal forebrain and medial temporal lobe. Both atlases were integrated to a canonical MRI (Colin27 from a young male participant by manually identifying homologous landmarks. The lower resolution atlas was then warped to fit the MRI based on the identified landmarks. A pseudo-MRI representation of the high-resolution atlas was created, and a nonlinear transformation was calculated in order to match the atlas to the template MRI. The atlas can then be warped to match the anatomy of Parkinson’s disease surgical candidates by using 3D automated nonlinear deformation methods. By way of functional validation of the atlas, the location of the sensory thalamus was correlated with stereotactic intraoperative physiological data. The position of subthalamic electrode positions in patients with Parkinson’s disease was also evaluated in the atlas-integrated MRI space. Finally, probabilistic maps of subthalamic stimulation electrodes were developed, in order to allow group analysis of the location of contacts associated with the best motor outcomes. We have therefore developed, and are continuing to validate, a high-resolution computerized MRI-integrated 3D histological atlas, which is useful in functional neurosurgery, and for functional and anatomical studies of the human basal ganglia, thalamus and basal forebrain.

  3. Computational fluid dynamics simulations of blood flow regularized by 3D phase contrast MRI

    Rispoli, Vinicius C; Nielsen, Jon; Nayak, Krishna S;

    2015-01-01

    BACKGROUND: Phase contrast magnetic resonance imaging (PC-MRI) is used clinically for quantitative assessment of cardiovascular flow and function, as it is capable of providing directly-measured 3D velocity maps. Alternatively, vascular flow can be estimated from model-based computation fluid...... approach in regularizing 3D flow fields is evaluated. METHODS: The proposed algorithm incorporates both a Newtonian fluid physics model and a linear PC-MRI signal model. The model equations are solved numerically using a modified CFD algorithm. The numerical solution corresponds to the optimal solution of...... dynamics (CFD) calculations. CFD provides arbitrarily high resolution, but its accuracy hinges on model assumptions, while velocity fields measured with PC-MRI generally do not satisfy the equations of fluid dynamics, provide limited resolution, and suffer from partial volume effects. The purpose of this...

  4. 3D-FT MRI of the facial nerve

    Girard, N. (Neuroradiology, Hopital Nord, 13 Marseille (France)); Raybaud, C. (Neuroradiology, Hopital Nord, 13 Marseille (France)); Poncet, M. (Neuroradiology, Hopital Nord, 13 Marseille (France))

    1994-08-01

    Contrast-enhanced 3D-FT MRI of the intrapetrous facial nerve was obtained in 38 patients with facial nerve disease, using a 1.0 T magnet and fast gradient-echo acquisition sequences. Contiguous millimetric sections were obtained, which could be reformatted in any desired plane. Acutely ill patients, were examined within the first 2 months, included: 24 with Bell's palsy and 6 with other acute disorders (Herpes zoster, trauma, neuroma, meningeal metastasis, middle ear granuloma). Six patients investigated more than a year after the onset of symptoms included 3 with congenital cholesteatoma, 2 with neuromas and one with a chronic Bell's palsy. The lesion was found incidentally in two cases (a suspected neurofibroma and a presumed drop metastasis from an astrocytoma). Patients with tumours had nodular, focally-enhancing lesions, except for the leptomeningeal metastasis in which the enhancement was linear. Linear, diffuse contrast enhancement of the facial nerve was found in trauma, and in the patient with a middle ear granuloma. Of the 24 patients with an acute Bell's palsy 15 exhibited linear contrast enhancement of the facial nerve. Three of these were lost to follow-up, but correlation of clinical outcome and contrast enhancement showed that only 4 of the 11 patients who made a complete recovery and all 10 patients with incomplete recovery demonstrated enhancement. Possible explanations for these findings are suggested by pathological data from the literature. 3D-FT imaging of the facial nerve thus yields direct information about the of the nerve condition and defines the morphological abnormalities. It can also demonstrate contrast enhancement which seems to have some prognostic value in acute idiopathic Bell's palsy. (orig.)

  5. Prospective comparison of 3D FIESTA versus fat-suppressed 3D SPGR MRI in evaluating knee cartilage lesions

    Aim: To prospectively compare the accuracy of three-dimensional fast imaging employing steady-state acquisition (3D FIESTA) sequences with that of fat-suppressed three-dimensional spoiled gradient-recalled (3D SPGR) in the diagnosis of knee articular cartilage lesions, using arthroscopy as the reference standard. Materials and methods: Fifty-eight knees in 54 patients (age range 21-82 years; mean 36 years) were prospectively evaluated by using sagittal 3D FIESTA and sagittal fat-suppressed 3D SPGR sequences. Articular cartilage lesions were graded on MRI and during arthroscopy with a modified Noyes scoring system. Sensitivity, specificity, and accuracy were assessed. Interobserver agreement was determined with κ statistics. Results: The performance of 3D FIESTA sequences (sensitivity, specificity, and accuracy were 80, 94, and 92%, respectively, for reader 1 and 76, 94, and 90%, respectively, for reader 2) was similar to that of fat-suppressed 3D SPGR sequences (sensitivity, specificity, and accuracy were 82, 92, and 90%, respectively, for reader 1 and 82, 90, and 88%, respectively, for reader 2) in the detection of knee articular cartilage lesions. The interobserver agreement varied from fair to good to excellent (kappa values from 0.43-0.83). Conclusion: 3D FIESTA has good diagnostic performance, comparable with fat-suppressed 3D SPGR in evaluating knee cartilage lesions, and it can be incorporated into routine knee MRI protocols due to the short acquisition time.

  6. 3D active surfaces for liver segmentation in multisequence MRI images.

    Bereciartua, Arantza; Picon, Artzai; Galdran, Adrian; Iriondo, Pedro

    2016-08-01

    Biopsies for diagnosis can sometimes be replaced by non-invasive techniques such as CT and MRI. Surgeons require accurate and efficient methods that allow proper segmentation of the organs in order to ensure the most reliable intervention planning. Automated liver segmentation is a difficult and open problem where CT has been more widely explored than MRI. MRI liver segmentation represents a challenge due to the presence of characteristic artifacts, such as partial volumes, noise and low contrast. In this paper, we present a novel method for multichannel MRI automatic liver segmentation. The proposed method consists of the minimization of a 3D active surface by means of the dual approach to the variational formulation of the underlying problem. This active surface evolves over a probability map that is based on a new compact descriptor comprising spatial and multisequence information which is further modeled by means of a liver statistical model. This proposed 3D active surface approach naturally integrates volumetric regularization in the statistical model. The advantages of the compact visual descriptor together with the proposed approach result in a fast and accurate 3D segmentation method. The method was tested on 18 healthy liver studies and results were compared to a gold standard made by expert radiologists. Comparisons with other state-of-the-art approaches are provided by means of nine well established quality metrics. The obtained results improve these methodologies, achieving a Dice Similarity Coefficient of 98.59. PMID:27282235

  7. Gel dosimetry for HDR Brachytherapy 3-D distribution through MRI

    Gel dosimetry using MRI is increasingly being utilized in contemporary literature. In our work we investigated the calibration of an acrylic gel by means of imaging with magnetic resonance and its application to the dose measurement in a 3D distribution 192Ir HDR brachytherapy treatment. Early gel dosimetry used Fricke gels and T1 relaxation time. In 2001 Fong et al. introduced a new normoxic gel known as ''MAGIC'' gel, the main components of which are Metacrylic Acid (polymer) and Hydroquinone ( polymerizing inhibitor). For this material, the evidence of radiation dose is indicated by a change in the T2 relaxation time on an MR image. Later studies varied concentrations of the MAGIC gel components in order to observe its effect and the behavior of the gel sensitivity, for magnetic fields over 0.5 T. In the 1980s a series of studies on dose quantification using magnetic resonance images and Fricke gels were performed by evaluating T1 signal through means of an Inversion Recovery technique. Polymer gels have been developed to avoid the adverse effects of oxygen that plague Fricke gels. Normoxic gels have a component which helps to capture the oxygen dissolved in the gel (MAGIC). For these type of gels, measurements of T2 are made using a Spin-Echo technique. For both groups of gels, the Relaxativity compared to either T1 or T2 varies linearly with the absorbed dose. Novotny et al. has obtained a dose response curve for BANG-2 gel showing a linear relationship of 1/T2 vs D[Gy]. In the work presented here we tested and found the same linear relation between spin-spin relaxation (R2=1/T2) versus dose up to 8.0Gy

  8. Development and Assessment of a New 3D Neuroanatomy Teaching Tool for MRI Training

    Drapkin, Zachary A.; Lindgren, Kristen A.; Lopez, Michael J.; Stabio, Maureen E.

    2015-01-01

    A computerized three-dimensional (3D) neuroanatomy teaching tool was developed for training medical students to identify subcortical structures on a magnetic resonance imaging (MRI) series of the human brain. This program allows the user to transition rapidly between two-dimensional (2D) MRI slices, 3D object composites, and a combined model in…

  9. Nonlaser-based 3D surface imaging

    Lu, Shin-yee; Johnson, R.K.; Sherwood, R.J. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    3D surface imaging refers to methods that generate a 3D surface representation of objects of a scene under viewing. Laser-based 3D surface imaging systems are commonly used in manufacturing, robotics and biomedical research. Although laser-based systems provide satisfactory solutions for most applications, there are situations where non laser-based approaches are preferred. The issues that make alternative methods sometimes more attractive are: (1) real-time data capturing, (2) eye-safety, (3) portability, and (4) work distance. The focus of this presentation is on generating a 3D surface from multiple 2D projected images using CCD cameras, without a laser light source. Two methods are presented: stereo vision and depth-from-focus. Their applications are described.

  10. Multimodal visualization of 3D enhanced MRI and CT of acoustic schwannoma and related structures

    Kucharski, Tomasz; Kujawinska, Malgorzata; Niemczyk, Kazimierz; Marchel, Andrzej

    2005-09-01

    According to the necessity of supporting vestibular schwannoma surgery, there is a demand to develop a convenient method of medical data visualization. The process of making choice of optimal operating access way has been uncomfortable for a surgeon so far, because there has been a necessity of analyzing two independent 3D images series (CT -bone tissues visible, MRI - soft tissues visible) in the region of ponto-cerebellar angle tumors. The authors propose a solution that will improve this process. The system used is equipped with stereoscopic helmet mounted display. It allows merged CT and MRI data representing tissues in the region of of ponto-cerebellar angle to be visualized in stereoscopic way. The process of data preparation for visualization includes: -automated segmentation algorithms, -different types of 3D images (CT, MRI) fusion. The authors focused on the development of novel algorithms for segmentation of vestibular schwannoma. It is important and difficult task due to different types of tumors and their inhomogeneous character dependent on growth models. The authors propose algorithms based on histogram spectrum and multimodal character of MRI imaging (T1 and T2 modes). However due to a variety of objects the library of algorithms with specific modifications matching to selected types of images is proposed. The applicability and functionality of the algorithms and library was proved on the series of data delivered by Warsaw Central Medical University Hospital.

  11. A study on the flip angle for an optimal T1-weighted image based on the 3D-THRIVE MRI technique: Focusing on the detection of a hepatocellular carcinoma (HCC)

    Dong, Kyung-Rae; Goo, Eun-Hoe; Lee, Jae-Seung; Chung, Woon-Kwan; Kim, Young-Jae

    2014-04-01

    This study examined the optimal flip angle (FA) for a T1-weighted image in the detection of a hepatocellular carcinoma (HCC). A 3D-T1-weighted high-resolution isotropic volume examination (THRIVE) technique was used to determine the dependence of the signal to noise ratio (SNR) and the contrast-to-noise ratio (CNR) on the change in FA. This study targeted 40 liver cancer patients (25 men and 15 women aged 50 to 70 years with a mean age of 60.32 ± 6.2 years) who visited this hospital to undergo an abdominal MRI examination from January to June 2013. A 3.0 Tesla MRI machine (Philips, Medical System, Achieva) and a MRI receiver coil for data reception with a 16-channel multicoil were used in this study. The THRIVE (repetition time (TR): 8.1 ms, echo time (TE): 3.7 ms, matrix: 172 × 172, slice thickness: 4 mm, gap: 2 mm, field of view (FOV): 350 mm, and band width (BW): 380.1 Hz) technique was applied as a pulse sequence. The time required for the examination was 19 seconds, and the breath-hold technique was used. Axial images were obtained at five FAs: 5, 10, 15, 20 and 25°. The signal intensities of the liver, the lesion and the background noise were measured based on the acquired images before the SNR and the CNR were calculated. To evaluate the image at the FA, we used SPSS for Windows ver. 17.0 to conduct a one-way ANOVA test. A Bonferroni test was conducted as a post-hoc test. The SNRs of the hemorrhagic HCC in the 3D-THRIVE technique were 35.50 ± 4.12, 97.00 ± 10.24, 66.09 ± 7.29, 53.84 ± 5.43, and 42.92 ± 5.11 for FAs of 5, 10, 15, 20, and 25°, respectively (p = 0.0430), whereas the corresponding CNRs were 30.50 ± 3.84, 43.00 ± 5.42, 36.54 ± 4.09, 32.30 ± 2.79, and 31.69 ± 3.21 (p = 0.0003). At a small FA of 10, the SNR and the CNR showed the highest values. As the FA was increased, the SNR and the CNR values showed a decreasing tendency. In conclusion, the optimal T1-weighted image FA should be set to 10° to detect a HCC by using the 3D

  12. Web-based interactive visualization of 3D video mosaics using X3D standard

    CHON Jaechoon; LEE Yang-Won; SHIBASAKI Ryosuke

    2006-01-01

    We present a method of 3D image mosaicing for real 3D representation of roadside buildings, and implement a Web-based interactive visualization environment for the 3D video mosaics created by 3D image mosaicing. The 3D image mosaicing technique developed in our previous work is a very powerful method for creating textured 3D-GIS data without excessive data processing like the laser or stereo system. For the Web-based open access to the 3D video mosaics, we build an interactive visualization environment using X3D, the emerging standard of Web 3D. We conduct the data preprocessing for 3D video mosaics and the X3D modeling for textured 3D data. The data preprocessing includes the conversion of each frame of 3D video mosaics into concatenated image files that can be hyperlinked on the Web. The X3D modeling handles the representation of concatenated images using necessary X3D nodes. By employing X3D as the data format for 3D image mosaics, the real 3D representation of roadside buildings is extended to the Web and mobile service systems.

  13. In vivo analysis of the human superficial cerebral venous anatomy by using 3D-MRI

    The purpose of this study is to show the reliability of three dimensional magnetic resonance imaging (3D-MRI), and to classify the drainage patterns of the superficial cerebral veins. At first, toothpicks were stuck into fixed brain surface of a dog. To examine the best methods for making 3D-MRI, the 3D-MRI, including the diameter of the holes, of the dog's brain were analyzed in four threshold values. The holes on the 3D-MRI appeared smaller than their actual size due to the partial volume effect. The low threshold showed more errors than the higher. This result showed it was necessary to display the good 3D-MRI to refer the original MR images. Next, the 3D-MRI of clinical patients who had brain tumors were correlated with operative findings especially in relation to the lesions and brain surface, vessels, ventricles. The relation between the lesions and brain surface, vessels were displayed well, but there were some problems with inadequate ventricular display. Finally, anatomical study using 3D-MRI was performed, because 3D-MRI could display the relation between the brain surface and the superficial cerebral veins in the basic studies. The third study demonstrated that the transverse frontal vein was found in 15%, vein of Trolard ran in front of the central sulcus in 91.5% and several anastomosing veins were frequently observed. These studies showed the progress of technology in bringing about a lot of new information by using 3D-MRI. (author)

  14. Volume-Rendering-Based Interactive 3D Measurement for Quantitative Analysis of 3D Medical Images

    Yakang Dai; Jian Zheng; Yuetao Yang; Duojie Kuai; Xiaodong Yang

    2013-01-01

    3D medical images are widely used to assist diagnosis and surgical planning in clinical applications, where quantitative measurement of interesting objects in the image is of great importance. Volume rendering is widely used for qualitative visualization of 3D medical images. In this paper, we introduce a volume-rendering-based interactive 3D measurement framework for quantitative analysis of 3D medical images. In the framework, 3D widgets and volume clipping are integrated with volume render...

  15. Regularization of DT-MRI Using 3D Median Filtering Methods

    Soondong Kwon

    2014-01-01

    Full Text Available DT-MRI (diffusion tensor magnetic resonance imaging tractography is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of the principal eigenvectors obtained from tensor matrix, which is different from the conventional isotropic MRI. Tractography based on DT-MRI is known to need many computations and is highly sensitive to noise. Hence, adequate regularization methods, such as image processing techniques, are in demand. Among many regularization methods we are interested in the median filtering method. In this paper, we extended two-dimensional median filters already developed to three-dimensional median filters. We compared four median filtering methods which are two-dimensional simple median method (SM2D, two-dimensional successive Fermat method (SF2D, three-dimensional simple median method (SM3D, and three-dimensional successive Fermat method (SF3D. Three kinds of synthetic data with different altitude angles from axial slices and one kind of human data from MR scanner are considered for numerical implementation by the four filtering methods.

  16. MRI 3D CISS– A Novel Imaging Modality in Diagnosing Trigeminal Neuralgia – A Review

    Besta, Radhika; Shankar, Y. Uday; Kumar, Ashwini; Prakash, S. Bhanu

    2016-01-01

    Trigeminal Neuralgia (TN) is considered as one of the most painful neurologic disorders affecting oro-facial region. TN is often diagnosed clinically based on the patients complete history of pain (severity, duration, episodes etc), relief of pain on test dose of Carbamazepine, regional block of long acting anaesthetic. However, Magnetic Resonance Imaging (MRI) plays an important and confirmatory role in showing Neuro Vascular Conflict (NVC) which is the commonest causative factor for TN. This article reviews the effectiveness of three-dimensional constructive interference in steady-state (3D-CISS) MRI in diagnosing the exact location, degree of neurovascular conflict responsible for classical as well as atypical TN and possible pre-treatment evaluation and treatment outcome. PMID:27135019

  17. MRI 3D CISS- A Novel Imaging Modality in Diagnosing Trigeminal Neuralgia - A Review.

    Besta, Radhika; Shankar, Y Uday; Kumar, Ashwini; Rajasekhar, E; Prakash, S Bhanu

    2016-03-01

    Trigeminal Neuralgia (TN) is considered as one of the most painful neurologic disorders affecting oro-facial region. TN is often diagnosed clinically based on the patients complete history of pain (severity, duration, episodes etc), relief of pain on test dose of Carbamazepine, regional block of long acting anaesthetic. However, Magnetic Resonance Imaging (MRI) plays an important and confirmatory role in showing Neuro Vascular Conflict (NVC) which is the commonest causative factor for TN. This article reviews the effectiveness of three-dimensional constructive interference in steady-state (3D-CISS) MRI in diagnosing the exact location, degree of neurovascular conflict responsible for classical as well as atypical TN and possible pre-treatment evaluation and treatment outcome. PMID:27135019

  18. 3D segmentation of masses in DCE-MRI images using FCM and adaptive MRF

    Zhang, Chengjie; Li, Lihua

    2014-03-01

    Dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) is a sensitive imaging modality for the detection of breast cancer. Automated segmentation of breast lesions in DCE-MRI images is challenging due to inherent signal-to-noise ratios and high inter-patient variability. A novel 3D segmentation method based on FCM and MRF is proposed in this study. In this method, a MRI image is segmented by spatial FCM, firstly. And then MRF segmentation is conducted to refine the result. We combined with the 3D information of lesion in the MRF segmentation process by using segmentation result of contiguous slices to constraint the slice segmentation. At the same time, a membership matrix of FCM segmentation result is used for adaptive adjustment of Markov parameters in MRF segmentation process. The proposed method was applied for lesion segmentation on 145 breast DCE-MRI examinations (86 malignant and 59 benign cases). An evaluation of segmentation was taken using the traditional overlap rate method between the segmented region and hand-drawing ground truth. The average overlap rates for benign and malignant lesions are 0.764 and 0.755 respectively. Then we extracted five features based on the segmentation region, and used an artificial neural network (ANN) to classify between malignant and benign cases. The ANN had a classification performance measured by the area under the ROC curve of AUC=0.73. The positive and negative predictive values were 0.86 and 0.58, respectively. The results demonstrate the proposed method not only achieves a better segmentation performance in accuracy also has a reasonable classification performance.

  19. Image Reconstruction from 2D stack of MRI/CT to 3D using Shapelets

    Arathi T; Latha Parameswaran

    2014-01-01

    Image reconstruction is an active research field, due to the increasing need for geometric 3D models in movie industry, games, virtual environments and in medical fields. 3D image reconstruction aims to arrive at the 3D model of an object, from its 2D images taken at different viewing angles. Medical images are multimodal, which includes MRI, CT scan image, PET and SPECT images. Of these, MRI and CT scan images of an organ when taken, is available as a stack of 2D images, taken at different a...

  20. Neural Network Based 3D Surface Reconstruction

    Vincy Joseph

    2009-11-01

    Full Text Available This paper proposes a novel neural-network-based adaptive hybrid-reflectance three-dimensional (3-D surface reconstruction model. The neural network combines the diffuse and specular components into a hybrid model. The proposed model considers the characteristics of each point and the variant albedo to prevent the reconstructed surface from being distorted. The neural network inputs are the pixel values of the two-dimensional images to be reconstructed. The normal vectors of the surface can then be obtained from the output of the neural network after supervised learning, where the illuminant direction does not have to be known in advance. Finally, the obtained normal vectors can be applied to integration method when reconstructing 3-D objects. Facial images were used for training in the proposed approach

  1. Registration of 2D x-ray images to 3D MRI by generating pseudo-CT data

    van der Bom, M. J.; Pluim, J. P. W.; Gounis, M. J.; van de Kraats, E. B.; Sprinkhuizen, S. M.; Timmer, J.; Homan, R.; Bartels, L. W.

    2011-02-01

    Spatial and soft tissue information provided by magnetic resonance imaging can be very valuable during image-guided procedures, where usually only real-time two-dimensional (2D) x-ray images are available. Registration of 2D x-ray images to three-dimensional (3D) magnetic resonance imaging (MRI) data, acquired prior to the procedure, can provide optimal information to guide the procedure. However, registering x-ray images to MRI data is not a trivial task because of their fundamental difference in tissue contrast. This paper presents a technique that generates pseudo-computed tomography (CT) data from multi-spectral MRI acquisitions which is sufficiently similar to real CT data to enable registration of x-ray to MRI with comparable accuracy as registration of x-ray to CT. The method is based on a k-nearest-neighbors (kNN)-regression strategy which labels voxels of MRI data with CT Hounsfield Units. The regression method uses multi-spectral MRI intensities and intensity gradients as features to discriminate between various tissue types. The efficacy of using pseudo-CT data for registration of x-ray to MRI was tested on ex vivo animal data. 2D-3D registration experiments using CT and pseudo-CT data of multiple subjects were performed with a commonly used 2D-3D registration algorithm. On average, the median target registration error for registration of two x-ray images to MRI data was approximately 1 mm larger than for x-ray to CT registration. The authors have shown that pseudo-CT data generated from multi-spectral MRI facilitate registration of MRI to x-ray images. From the experiments it could be concluded that the accuracy achieved was comparable to that of registering x-ray images to CT data.

  2. Automatic extraction of soft tissues from 3D MRI head images using model driven analysis

    This paper presents an automatic extraction system (called TOPS-3D : Top Down Parallel Pattern Recognition System for 3D Images) of soft tissues from 3D MRI head images by using model driven analysis algorithm. As the construction of system TOPS we developed, two concepts have been considered in the design of system TOPS-3D. One is the system having a hierarchical structure of reasoning using model information in higher level, and the other is a parallel image processing structure used to extract plural candidate regions for a destination entity. The new points of system TOPS-3D are as follows. (1) The TOPS-3D is a three-dimensional image analysis system including 3D model construction and 3D image processing techniques. (2) A technique is proposed to increase connectivity between knowledge processing in higher level and image processing in lower level. The technique is realized by applying opening operation of mathematical morphology, in which a structural model function defined in higher level by knowledge representation is immediately used to the filter function of opening operation as image processing in lower level. The system TOPS-3D applied to 3D MRI head images consists of three levels. First and second levels are reasoning part, and third level is image processing part. In experiments, we applied 5 samples of 3D MRI head images with size 128 x 128 x 128 pixels to the system TOPS-3D to extract the regions of soft tissues such as cerebrum, cerebellum and brain stem. From the experimental results, the system is robust for variation of input data by using model information, and the position and shape of soft tissues are extracted corresponding to anatomical structure. (author)

  3. Three-dimensional (3D) MRI for indication of breast conserving surgery

    3D-MRI has the following advantages: To observe the whole breast from any direction. To calculate each volume of the main tumor, whole breast and the planned surgical area. At this time, Gd-enhanced 3D-MRI was performed to 56 patients with 58 lesions to determine indication of breast conserving surgery. Extensive intraductal component (EIC) was evaluated by 3D-MRI preoperatively and it was confirmed by pathological examination postoperatively. The main tumor was detected in 56 of 58 lesions by 3D-MRI (sensitivity, 96.6%). EIC (+) was pointed out in 19 of 27 lesions (sensitivity, 70.4%) EIC (-) was correctly estimated in 19 of 29 lesions (specificity, 65.5%). Next, the volumes of the main lesion, whole breast and the planned surgical area were calculated (23 of 56 patients). The volume ratio of the main tumor/whole breast and the planned surgical area/whole breast were compared to the postoperative cosmetic result respectively. To maintain the volume ratio of the planned surgical area/whole breast under 20% was one of the key factors to obtain good cosmetic result. Therefore, 3-D MRI may become indispensable to indication of breast conserving surgery. (author)

  4. 3-D MRI/CT fusion imaging of the lumbar spine

    The objective was to demonstrate the feasibility of MRI/CT fusion in demonstrating lumbar nerve root compromise. We combined 3-dimensional (3-D) computed tomography (CT) imaging of bone with 3-D magnetic resonance imaging (MRI) of neural architecture (cauda equina and nerve roots) for two patients using VirtualPlace software. Although the pathological condition of nerve roots could not be assessed using MRI, myelography or CT myelography, 3-D MRI/CT fusion imaging enabled unambiguous, 3-D confirmation of the pathological state and courses of nerve roots, both inside and outside the foraminal arch, as well as thickening of the ligamentum flavum and the locations, forms and numbers of dorsal root ganglia. Positional relationships between intervertebral discs or bony spurs and nerve roots could also be depicted. Use of 3-D MRI/CT fusion imaging for the lumbar vertebral region successfully revealed the relationship between bone construction (bones, intervertebral joints, and intervertebral disks) and neural architecture (cauda equina and nerve roots) on a single film, three-dimensionally and in color. Such images may be useful in elucidating complex neurological conditions such as degenerative lumbar scoliosis(DLS), as well as in diagnosis and the planning of minimally invasive surgery. (orig.)

  5. TU-F-BRF-06: 3D Pancreas MRI Segmentation Using Dictionary Learning and Manifold Clustering

    Purpose: The recent advent of MRI guided radiotherapy machines has lent an exciting platform for soft tissue target localization during treatment. However, tools to efficiently utilize MRI images for such purpose have not been developed. Specifically, to efficiently quantify the organ motion, we develop an automated segmentation method using dictionary learning and manifold clustering (DLMC). Methods: Fast 3D HASTE and VIBE MR images of 2 healthy volunteers and 3 patients were acquired. A bounding box was defined to include pancreas and surrounding normal organs including the liver, duodenum and stomach. The first slice of the MRI was used for dictionary learning based on mean-shift clustering and K-SVD sparse representation. Subsequent images were iteratively reconstructed until the error is less than a preset threshold. The preliminarily segmentation was subject to the constraints of manifold clustering. The segmentation results were compared with the mean shift merging (MSM), level set (LS) and manual segmentation methods. Results: DLMC resulted in consistently higher accuracy and robustness than comparing methods. Using manual contours as the ground truth, the mean Dices indices for all subjects are 0.54, 0.56 and 0.67 for MSM, LS and DLMC, respectively based on the HASTE image. The mean Dices indices are 0.70, 0.77 and 0.79 for the three methods based on VIBE images. DLMC is clearly more robust on the patients with the diseased pancreas while LS and MSM tend to over-segment the pancreas. DLMC also achieved higher sensitivity (0.80) and specificity (0.99) combining both imaging techniques. LS achieved equivalent sensitivity on VIBE images but was more computationally inefficient. Conclusion: We showed that pancreas and surrounding normal organs can be reliably segmented based on fast MRI using DLMC. This method will facilitate both planning volume definition and imaging guidance during treatment

  6. TU-F-BRF-06: 3D Pancreas MRI Segmentation Using Dictionary Learning and Manifold Clustering

    Gou, S; Rapacchi, S; Hu, P; Sheng, K [UCLA School of Medicine, Los Angeles, CA (United States)

    2014-06-15

    Purpose: The recent advent of MRI guided radiotherapy machines has lent an exciting platform for soft tissue target localization during treatment. However, tools to efficiently utilize MRI images for such purpose have not been developed. Specifically, to efficiently quantify the organ motion, we develop an automated segmentation method using dictionary learning and manifold clustering (DLMC). Methods: Fast 3D HASTE and VIBE MR images of 2 healthy volunteers and 3 patients were acquired. A bounding box was defined to include pancreas and surrounding normal organs including the liver, duodenum and stomach. The first slice of the MRI was used for dictionary learning based on mean-shift clustering and K-SVD sparse representation. Subsequent images were iteratively reconstructed until the error is less than a preset threshold. The preliminarily segmentation was subject to the constraints of manifold clustering. The segmentation results were compared with the mean shift merging (MSM), level set (LS) and manual segmentation methods. Results: DLMC resulted in consistently higher accuracy and robustness than comparing methods. Using manual contours as the ground truth, the mean Dices indices for all subjects are 0.54, 0.56 and 0.67 for MSM, LS and DLMC, respectively based on the HASTE image. The mean Dices indices are 0.70, 0.77 and 0.79 for the three methods based on VIBE images. DLMC is clearly more robust on the patients with the diseased pancreas while LS and MSM tend to over-segment the pancreas. DLMC also achieved higher sensitivity (0.80) and specificity (0.99) combining both imaging techniques. LS achieved equivalent sensitivity on VIBE images but was more computationally inefficient. Conclusion: We showed that pancreas and surrounding normal organs can be reliably segmented based on fast MRI using DLMC. This method will facilitate both planning volume definition and imaging guidance during treatment.

  7. Comparison of 3D orientation distribution functions measured with confocal microscopy and diffusion MRI.

    Schilling, Kurt; Janve, Vaibhav; Gao, Yurui; Stepniewska, Iwona; Landman, Bennett A; Anderson, Adam W

    2016-04-01

    The ability of diffusion MRI (dMRI) fiber tractography to non-invasively map three-dimensional (3D) anatomical networks in the human brain has made it a valuable tool in both clinical and research settings. However, there are many assumptions inherent to any tractography algorithm that can limit the accuracy of the reconstructed fiber tracts. Among them is the assumption that the diffusion-weighted images accurately reflect the underlying fiber orientation distribution (FOD) in the MRI voxel. Consequently, validating dMRI's ability to assess the underlying fiber orientation in each voxel is critical for its use as a biomedical tool. Here, using post-mortem histology and confocal microscopy, we present a method to perform histological validation of orientation functions in 3D, which has previously been limited to two-dimensional analysis of tissue sections. We demonstrate the ability to extract the 3D FOD from confocal z-stacks, and quantify the agreement between the MRI estimates of orientation information obtained using constrained spherical deconvolution (CSD) and the true geometry of the fibers. We find an orientation error of approximately 6° in voxels containing nearly parallel fibers, and 10-11° in crossing fiber regions, and note that CSD was unable to resolve fibers crossing at angles below 60° in our dataset. This is the first time that the 3D white matter orientation distribution is calculated from histology and compared to dMRI. Thus, this technique serves as a gold standard for dMRI validation studies - providing the ability to determine the extent to which the dMRI signal is consistent with the histological FOD, and to establish how well different dMRI models can predict the ground truth FOD. PMID:26804781

  8. Physics Contributions and Clinical Outcome With 3D-MRI-Based Pulsed-Dose-Rate Intracavitary Brachytherapy in Cervical Cancer Patients

    Purpose: To assess the physics contributions and clinical outcome with three-dimensional magnetic resonance imaging-guided pulsed-dose-rate (PDR) intracavitary brachytherapy in cervical cancer patients. Methods and Materials: The data from 45 patients with primary locally advanced cervical carcinoma were analyzed. The median tumor cervical volume was 64.0 cm3 (range, 3-178). Of the 45 patients, 24 (53%) had histologic and/or radiologic pelvic involvement. After pelvic with or without para-aortic concomitant chemoradiotherapy, a PDR brachytherapy boost was delivered to a three-dimensional magnetic resonance imaging-based clinical target volume, taking into account the dose-volume constraints for critical organs and optimization of the target volume coverage. Results: At a median follow-up of 26 months (range, 9-47), the 2-year overall survival and disease-free survival rate was 78% and 73%, respectively. At the last follow-up visit, the disease of all patients remained locally controlled. Adding external beam radiotherapy and PDR using the equivalent dose in 2-Gy fractions model, the median dose received by 100% and 90% of the target was 54.4 Gyα/β10 and 63.5 Gyα/β10 for the intermediate-risk clinical target volume and 61.6 Gyα/β10 and 74.9 Gyα/β10 for the high-risk clinical target volume, respectively. Of the 45 patients, 23 and 2 developed acute Grade 1-2 and Grade 3 complications, respectively; 21 patients presented with delayed Grade 1-2 complications. One other patient presented with Grade 3 vesicovaginal fistula. No Grade 4 or greater complications, whether acute or delayed, were observed. Conclusion: Magnetic resonance imaging-guided PDR brachytherapy with optimization integrating the limits of tolerance to critical organs allows for excellent local control rates. Moreover, the present results have confirmed that the ability to optimize dwell times can contribute to an improvement in local control rates with a low level of late side effects.

  9. Utility of reconstructed image from 3-D MRI in the region of oral cavity

    Murakami, Shumei; Kakimoto, Naoya; Nakatani, Atsutoshi; Furuya, Shigeo; Furukawa, Shouhei; Fuchihata, Hajime [Osaka Univ., Suita (Japan). School of Dentistry

    1998-12-01

    The 3-D MRI with short TR was performed in the region of oral cavity, jaw and face, and utility of the reconstructed image was examined. Subjects were 8 healthy volunteers and 12 patients. The 3-D MRI was performed using SPGR with the following parameters; TR: 8 or 9 msec, TE: 2 or 3 msec, and FA: 20-30 degrees. Imaging direction was vertical to body axis. The matrix number was 256 x 192, slice thickness was 1 mm, slice interval was 0 and slice number was 128. The obtained image was reconstructed using software Reformat``. Detectability of temporomandibular joint disc was not enough in 8 of 20 cases. Detectability of mandibular canal was clear in 18 of 20 cases. In panorama MRI, soft tissue such as submandibular gland was detected. But, in hard tissue such as teeth or maxilla, there was a more little information in panorama MRI than in panorama X-ray photography. (K.H.)

  10. High-resolution MRI of the labyrinth. Optimization of scan parameters with 3D-FSE

    The aim of our study was to optimize the parameters of high-resolution MRI of the labyrinth with a 3D fast spin-echo (3D-FSE) sequence. We investigated repetition time (TR), echo time (TE), Matrix, field of view (FOV), and coil selection in terms of CNR (contrast-to-noise ratio) and SNR (signal-to-noise ratio) by comparing axial images and/or three-dimensional images. The optimal 3D-FSE sequence parameters were as follows: 1.5 Tesla MR unit (Signa LX, GE Medical Systems), 3D-FSE sequence, dual 3-inch surface coil, acquisition time=12.08 min, TR=5000 msec, TE=300 msec, 3 number of excitations (NEX), FOV=12 cm, matrix=256 x 256, slice thickness=0.5 mm/0.0 sp, echo train=64, bandwidth=±31.5 kHz. High-resolution MRI of the labyrinth using the optimized 3D-FSE sequence parameters permits visualization of important anatomic details (such as scala tympani and scala vestibuli), making it possible to determine inner ear anomalies and the patency of cochlear turns. To obtain excellent heavily T2-weighted axial and three-dimensional images in the labyrinth, high CNR, SNR, and spatial resolution are significant factors at the present time. Furthermore, it is important not only to optimize the scan parameters of 3D-FSE but also to select an appropriate coil for high-resolution MRI of the labyrinth. (author)

  11. Automatic extraction of soft tissues from 3D MRI images of the head

    This paper presents an automatic extraction method of soft tissues from 3D MRI images of the head. A 3D region growing algorithm is used to extract soft tissues such as cerebrum, cerebellum and brain stem. Four information sources are used to control the 3D region growing. Model of each soft tissue has been constructed in advance and provides a 3D region growing space. Head skin area which is automatically extracted from input image provides an unsearchable area. Zero-crossing points are detected by using Laplacian operator, and by examining sign change between neighborhoods. They are used as a control condition in the 3D region growing process. Graylevels of voxels are also directly used to extract each tissue region as a control condition. Experimental results applied to 19 samples show that the method is successful. (author)

  12. A Visual Similarity-Based 3D Search Engine

    Lmaati, Elmustapha Ait; Oirrak, Ahmed El; M.N. Kaddioui

    2009-01-01

    Retrieval systems for 3D objects are required because 3D databases used around the web are growing. In this paper, we propose a visual similarity based search engine for 3D objects. The system is based on a new representation of 3D objects given by a 3D closed curve that captures all information about the surface of the 3D object. We propose a new 3D descriptor, which is a combination of three signatures of this new representation, and we implement it in our interactive web based search engin...

  13. Complex 3D Blood Flow Pathways in Two Cases of Aorta to Right Heart Fistulae: a 4D Flow MRI study

    Thakrar, Darshit; Popescu, Andrada; Gupta, Suraj; de Freitas, Andrew; Russell, Hyde; Carr, James; Markl, Michael

    2013-01-01

    We present an analysis of 3D blood flow in two cases of Sinus of Valsalva to right heart fistulae based on 4D flow MRI. Despite similar underlying pathology, 3D visualization revealed intricate differences in flow patterns connecting the systemic and pulmonary circulation. The cases illustrates the potential of 4D flow MRI to complement the evaluation of complex structural heart disease by assessing complex flow dynamics and providing quantitative information of flow ratios and flow rates.

  14. Microassembly for complex and solid 3D MEMS by 3D Vision-based control.

    Tamadazte, Brahim; Le Fort-Piat, Nadine; Marchand, Eric; Dembélé, Sounkalo

    2009-01-01

    This paper describes the vision-based methods developed for assembly of complex and solid 3D MEMS (micro electromechanical systems) structures. The microassembly process is based on sequential robotic operations such as planar positioning, gripping, orientation in space and insertion tasks. Each of these microassembly tasks is performed using a posebased visual control. To be able to control the microassembly process, a 3D model-based tracker is used. This tracker able to directly provides th...

  15. Direct 3D Painting with a Metaball-Based Paintbrush

    WAN Huagen; JIN Xiaogang; BAO Hujun

    2000-01-01

    This paper presents a direct 3D painting algorithm for polygonal models in 3D object-space with a metaball-based paintbrush in virtual environment.The user is allowed to directly manipulate the parameters used to shade the surface of the 3D shape by applying the pigment to its surface with direct 3D manipulation through a 3D flying mouse.

  16. Plaque characterization in ex vivo MRI evaluated by dense 3D correspondence with histology

    Engelen, A. van; de Bruijne, Marleen; Klein, S.;

    2011-01-01

    . Histological slices of human atherosclerotic plaques were manually segmented into necrotic core, fibrous tissue and calcification. Classification of these three components was voxelwise evaluated. As features the intensity, gradient magnitude and Laplacian in four MRI sequences after different degrees of......Automatic quantification of carotid artery plaque composition is important in the development of methods that distinguish vulnerable from stable plaques. MRI has shown to be capable of imaging different components noninvasively. We present a new plaque classification method which uses 3D...... registration of histology data with ex vivo MRI data, using non-rigid registration, both for training and evaluation. This is more objective than previously presented methods, as it eliminates selection bias that is introduced when 2D MRI slices are manually matched to histological slices before evaluation...

  17. Coronary Arteries Segmentation Based on the 3D Discrete Wavelet Transform and 3D Neutrosophic Transform

    Shuo-Tsung Chen

    2015-01-01

    Full Text Available Purpose. Most applications in the field of medical image processing require precise estimation. To improve the accuracy of segmentation, this study aimed to propose a novel segmentation method for coronary arteries to allow for the automatic and accurate detection of coronary pathologies. Methods. The proposed segmentation method included 2 parts. First, 3D region growing was applied to give the initial segmentation of coronary arteries. Next, the location of vessel information, HHH subband coefficients of the 3D DWT, was detected by the proposed vessel-texture discrimination algorithm. Based on the initial segmentation, 3D DWT integrated with the 3D neutrosophic transformation could accurately detect the coronary arteries. Results. Each subbranch of the segmented coronary arteries was segmented correctly by the proposed method. The obtained results are compared with those ground truth values obtained from the commercial software from GE Healthcare and the level-set method proposed by Yang et al., 2007. Results indicate that the proposed method is better in terms of efficiency analyzed. Conclusion. Based on the initial segmentation of coronary arteries obtained from 3D region growing, one-level 3D DWT and 3D neutrosophic transformation can be applied to detect coronary pathologies accurately.

  18. STAR3D: a stack-based RNA 3D structural alignment tool.

    Ge, Ping; Zhang, Shaojie

    2015-11-16

    The various roles of versatile non-coding RNAs typically require the attainment of complex high-order structures. Therefore, comparing the 3D structures of RNA molecules can yield in-depth understanding of their functional conservation and evolutionary history. Recently, many powerful tools have been developed to align RNA 3D structures. Although some methods rely on both backbone conformations and base pairing interactions, none of them consider the entire hierarchical formation of the RNA secondary structure. One of the major issues is that directly applying the algorithms of matching 2D structures to the 3D coordinates is particularly time-consuming. In this article, we propose a novel RNA 3D structural alignment tool, STAR3D, to take into full account the 2D relations between stacks without the complicated comparison of secondary structures. First, the 3D conserved stacks in the inputs are identified and then combined into a tree-like consensus. Afterward, the loop regions are compared one-to-one in accordance with their relative positions in the consensus tree. The experimental results show that the prediction of STAR3D is more accurate for both non-homologous and homologous RNAs than other state-of-the-art tools with shorter running time. PMID:26184875

  19. Automatic 3D segmentation of spinal cord MRI using propagated deformable models

    De Leener, B.; Cohen-Adad, J.; Kadoury, S.

    2014-03-01

    Spinal cord diseases or injuries can cause dysfunction of the sensory and locomotor systems. Segmentation of the spinal cord provides measures of atrophy and allows group analysis of multi-parametric MRI via inter-subject registration to a template. All these measures were shown to improve diagnostic and surgical intervention. We developed a framework to automatically segment the spinal cord on T2-weighted MR images, based on the propagation of a deformable model. The algorithm is divided into three parts: first, an initialization step detects the spinal cord position and orientation by using the elliptical Hough transform on multiple adjacent axial slices to produce an initial tubular mesh. Second, a low-resolution deformable model is iteratively propagated along the spinal cord. To deal with highly variable contrast levels between the spinal cord and the cerebrospinal fluid, the deformation is coupled with a contrast adaptation at each iteration. Third, a refinement process and a global deformation are applied on the low-resolution mesh to provide an accurate segmentation of the spinal cord. Our method was evaluated against a semi-automatic edge-based snake method implemented in ITK-SNAP (with heavy manual adjustment) by computing the 3D Dice coefficient, mean and maximum distance errors. Accuracy and robustness were assessed from 8 healthy subjects. Each subject had two volumes: one at the cervical and one at the thoracolumbar region. Results show a precision of 0.30 +/- 0.05 mm (mean absolute distance error) in the cervical region and 0.27 +/- 0.06 mm in the thoracolumbar region. The 3D Dice coefficient was of 0.93 for both regions.

  20. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    Hernandez D, J.; Cordova F, T. [Universidad de Guanajuato, Campus Leon, Departamento de Ingenieria Fisica, Loma del Bosque No. 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Cruz A, I., E-mail: hernandezdj.gto@gmail.com [CONACYT, Centro de Investigacion en Matematicas, A. C., Jalisco s/n, Col. Valenciana, 36000 Guanajuato, Gto. (Mexico)

    2015-10-15

    This paper presents a novel presents an approach based on differences of intensities for the identification of vascular structures in medical images from MRI studies of type time of flight method (TOF). The plating method hypothesis gave high intensities belonging to the vascular system image type TOF can be segmented by thresholding of the histogram. The enhanced vascular structures is performed using the filter Vesselness, upon completion of a decision based on fuzzy thresholding minimizes error in the selection of vascular structures. It will give a brief introduction to the vascular system problems and how the images have helped diagnosis, is summarized the physical history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, clear images and less noise compared with edge detection methods. (Author)

  1. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    This paper presents a novel presents an approach based on differences of intensities for the identification of vascular structures in medical images from MRI studies of type time of flight method (TOF). The plating method hypothesis gave high intensities belonging to the vascular system image type TOF can be segmented by thresholding of the histogram. The enhanced vascular structures is performed using the filter Vesselness, upon completion of a decision based on fuzzy thresholding minimizes error in the selection of vascular structures. It will give a brief introduction to the vascular system problems and how the images have helped diagnosis, is summarized the physical history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, clear images and less noise compared with edge detection methods. (Author)

  2. Validation of Continuously Tagged MRI for the Measurement of Dynamic 3D Skeletal Muscle Tissue Deformation

    Moerman, Kevin M; Simms, Ciaran K; Lamerichs, Rolf M; Stoker, Jaap; Nederveen, Aart J

    2016-01-01

    A SPAMM tagged MRI methodology is presented allowing continuous (3.3-3.6 Hz) sampling of 3D dynamic soft tissue deformation using non-segmented 3D acquisitions. The 3D deformation is reconstructed by the combination of 3 mutually orthogonal tagging directions, thus requiring only 3 repeated motion cycles. In addition a fully automatic post-processing framework is presented employing Gabor scale-space and filter-bank analysis for tag extrema segmentation and triangulated surface fitting aided by Gabor filter bank derived surface normals. Deformation is derived following tracking of tag surface triplet triangle intersections. The dynamic deformation measurements were validated using indentation tests (~20 mm deep at 12 mm/s) on a silicone gel soft tissue phantom containing contrasting markers which provide a reference measure of deformation. In addition, the techniques were evaluated in-vivo for dynamic skeletal muscle tissue deformation measurement during indentation of the biceps region of the upper arm in a ...

  3. Audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI

    Lee, D.; Greer, P. B.; Arm, J.; Keall, P.; Kim, T.

    2014-03-01

    The purpose of this study was to test the hypothesis that audiovisual (AV) biofeedback can improve image quality and reduce scan time for respiratory-gated 3D thoracic MRI. For five healthy human subjects respiratory motion guidance in MR scans was provided using an AV biofeedback system, utilizing real-time respiratory motion signals. To investigate the improvement of respiratory-gated 3D MR images between free breathing (FB) and AV biofeedback (AV), each subject underwent two imaging sessions. Respiratory-related motion artifacts and imaging time were qualitatively evaluated in addition to the reproducibility of external (abdominal) motion. In the results, 3D MR images in AV biofeedback showed more anatomic information such as a clear distinction of diaphragm, lung lobes and sharper organ boundaries. The scan time was reduced from 401±215 s in FB to 334±94 s in AV (p-value 0.36). The root mean square variation of the displacement and period of the abdominal motion was reduced from 0.4±0.22 cm and 2.8±2.5 s in FB to 0.1±0.15 cm and 0.9±1.3 s in AV (p-value of displacement biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI. These results suggest that AV biofeedback has the potential to be a useful motion management tool in medical imaging and radiation therapy procedures.

  4. A newly developed removable dental device for fused 3-D MRI/Meg imaging

    Kuboki, Takuo [Okayama Univ. (Japan). Dental School; Clark, G.T.; Akhtari, M.; Sutherling, W.W.

    1999-06-01

    Recently 3-D imaging techniques have been used to shed light on the role of abnormal brain functions in such conditions as nocturnal bruxism and orofacial pain. In order to achieve precise 3-D image fusion between magnetic resonance images (MRI) and magnetoencephalography (MEG) data, we developed a removable dental device which attaches rigidly to the teeth. Using this device, correlation of MEG and MRI data points was achieved by the co-registration of 3 or more fiducial points. Using a Polhemus 3-space digitizer the locations of the points were registered on MEG and then a small amount of high-water-content material was placed at each point for registering these same points on MRI. The mean reproducibility of interpoint distances, determined for 2 subjects, was between 0.59 and 0.82 mm. Using a Monte Carlo statistical analysis we determined that the accuracy of a posterior projection from the fiducial points to any point within the strata of the brain is {+-}3.3 mm. The value of this device is that it permits reasonably precise and repeatable co-registration of these points and yet it is easily removed and replaced by the patient. Obviously such a device could also be adapted for use in diagnosis and analysis of brain functions related with other various sensory and motor functions (e.g., taste, pain, clenching) in maxillofacial region using MRI and MEG. (author)

  5. A newly developed removable dental device for fused 3-D MRI/Meg imaging

    Recently 3-D imaging techniques have been used to shed light on the role of abnormal brain functions in such conditions as nocturnal bruxism and orofacial pain. In order to achieve precise 3-D image fusion between magnetic resonance images (MRI) and magnetoencephalography (MEG) data, we developed a removable dental device which attaches rigidly to the teeth. Using this device, correlation of MEG and MRI data points was achieved by the co-registration of 3 or more fiducial points. Using a Polhemus 3-space digitizer the locations of the points were registered on MEG and then a small amount of high-water-content material was placed at each point for registering these same points on MRI. The mean reproducibility of interpoint distances, determined for 2 subjects, was between 0.59 and 0.82 mm. Using a Monte Carlo statistical analysis we determined that the accuracy of a posterior projection from the fiducial points to any point within the strata of the brain is ±3.3 mm. The value of this device is that it permits reasonably precise and repeatable co-registration of these points and yet it is easily removed and replaced by the patient. Obviously such a device could also be adapted for use in diagnosis and analysis of brain functions related with other various sensory and motor functions (e.g., taste, pain, clenching) in maxillofacial region using MRI and MEG. (author)

  6. 2D and 3D MRI features of classic bladder exstrophy

    The bladder exstrophy–epispadias complex (EEC) represents a spectrum of rare and surgically correctable congenital anomalies. Classic bladder exstrophy (CBE) stands between epispadias and cloacal exstrophy (CE) in the severity spectrum, and is the most commonly encountered type. CBE involves congenital defects of the bladder, abdominal wall, pelvic floor, and bony pelvis. With the growing understanding of the detrimental effects of radiation in children, magnetic resonance imaging (MRI) is progressively been utilized in the preoperative work-up and post-surgical follow-up of these patients. MRI provides valuable information for planning and evaluating the optimal surgical techniques for closure of CBE. The aim of this paper is to provide a review of the two- (2D) and three-dimensional (3D) MRI features of CBE including a detailed analytical description of the anatomy of the pelvic floor in affected patients

  7. Random-Profiles-Based 3D Face Recognition System

    Joongrock Kim; Sunjin Yu; Sangyoun Lee

    2014-01-01

    In this paper, a noble nonintrusive three-dimensional (3D) face modeling system for random-profile-based 3D face recognition is presented. Although recent two-dimensional (2D) face recognition systems can achieve a reliable recognition rate under certain conditions, their performance is limited by internal and external changes, such as illumination and pose variation. To address these issues, 3D face recognition, which uses 3D face data, has recently received much attention. However, the perf...

  8. Regularization of DT-MRI Using 3D Median Filtering Methods

    Soondong Kwon; Dongyoun Kim; Bongsoo Han; Kiwoon Kwon

    2014-01-01

    DT-MRI (diffusion tensor magnetic resonance imaging) tractography is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of the principal eigenvectors obtained from tensor matrix, which is different from the conventional isotropic MRI. Tractography based on DT-MRI is known to need many computations and is highly sensitive to noise. Hence, adequate regularization methods, such as image processing techniques, are in demand. Among man...

  9. Meshless deformable models for 3D cardiac motion and strain analysis from tagged MRI.

    Wang, Xiaoxu; Chen, Ting; Zhang, Shaoting; Schaerer, Joël; Qian, Zhen; Huh, Suejung; Metaxas, Dimitris; Axel, Leon

    2015-01-01

    Tagged magnetic resonance imaging (TMRI) provides a direct and noninvasive way to visualize the in-wall deformation of the myocardium. Due to the through-plane motion, the tracking of 3D trajectories of the material points and the computation of 3D strain field call for the necessity of building 3D cardiac deformable models. The intersections of three stacks of orthogonal tagging planes are material points in the myocardium. With these intersections as control points, 3D motion can be reconstructed with a novel meshless deformable model (MDM). Volumetric MDMs describe an object as point cloud inside the object boundary and the coordinate of each point can be written in parametric functions. A generic heart mesh is registered on the TMRI with polar decomposition. A 3D MDM is generated and deformed with MR image tagging lines. Volumetric MDMs are deformed by calculating the dynamics function and minimizing the local Laplacian coordinates. The similarity transformation of each point is computed by assuming its neighboring points are making the same transformation. The deformation is computed iteratively until the control points match the target positions in the consecutive image frame. The 3D strain field is computed from the 3D displacement field with moving least squares. We demonstrate that MDMs outperformed the finite element method and the spline method with a numerical phantom. Meshless deformable models can track the trajectory of any material point in the myocardium and compute the 3D strain field of any particular area. The experimental results on in vivo healthy and patient heart MRI show that the MDM can fully recover the myocardium motion in three dimensions. PMID:25157446

  10. Role of 3D MRI with proset technique in the evaluation of lumbar radiculopathy.

    Grasso, D; Borreggine, C; Melchionda, D; Bristogiannis, C; Stoppino, L P; Macarini, L

    2013-01-01

    The aim of this study is to demonstrate the effectiveness of 3-Dimensional Magnetic Resonance Imaging (3D MRI) using the ProSet technique in the diagnosis of lumbar radiculopathy and to compare morphological findings with clinical and neurophysiological data. 40 patients suffering from L5 or S1 mono-radiculopathy caused by a disc herniation were evaluated through preliminary clinical assessment and electromyography (EMG) technique. Both conventional spin-echo sequences and 3D coronal FFE with selective water excitation (ProSet imaging) were acquired. Indentation, swelling and tilt angle of the nerve root were assessed by means of a 3D MR radiculography. 3D ProSet multiplanar reconstructions (MPR) were used for quantitative measurements of L5 and S1 nerve root widths. Widths of the symptomatic nerve root were compared with those of the contralateral nerve. Data were processed using Epi Info 3.3 software (CDC, Atlanta, GA, USA) and were compared through a paired t-Student test. We observed an abnormal tilt angle in 22 patients (57,2 percent, P less than 0.05). Morphologic alterations such as monolateral swelling or indentation of the involved roots were found in 36 patients (90 percent, P less than0.01) using 3D MR radiculography. In 10 patients, EMG revealed more nerve roots involved, while 3D FFE with ProSet technique shows a single root involved. In 2 patients, alterations were demonstrated only through EMG technique. We suggest that 3D MR radiculography can provide more information than other techniques about symptomatic disc herniation, supporting the detection of morphological changes of all nerve segments. 3D FFE with ProSet technique demonstrates high sensibility to exactly identify the level of the root involved and can provide an extremely useful tool to lead a surgical planning. PMID:24152846

  11. MRI of the cervical spine with 3D gradient echo sequence at 3 T: initial experience

    Aim: The aim of this study was to compare three-dimensional (3D) high resolution T2*-weighted gradient echo (3D FFE) magnetic resonance (MR) sequence with conventional 2D T2-weighted turbo spin echo (TSE) MR sequence for imaging of the cervical spine, especially to assess the detectability of the internal anatomy of the cervical spinal cord, i.e. to distinguish the grey and white matter. Methods: Fifteen volunteers were examined at 3.0T MR unit. Signal-to-noise (SNR), contrast-to-noise (CNR) and image homogeneity were evaluated. In the visual analysis, the visibility of anatomical structures of the cervical spine and artifacts were assessed. The nonparametric method of paired sample t-test was adopted to evaluate the differences between the sequences. Results: The 3D FFE sequence provided better results for CNR, cerebrospinal fluid (CSF) versus white matter, grey matter, disk and bone. Moreover, it yielded good results for the CNR grey matter versus white matter. The butterfly-shaped “H” is clearly displayed in the 3D FFE sequence. The statistical analysis revealed the statistically significant difference between the 2D TSE and 3D FFE sequences for the contrast of CSF versus spinal cord (both grey matter and white matter). Conclusion: The 3D FFE sequence in MR imaging of the cervical spinal cord is superior in delineation of spinal cord anatomical structures compared to 2D TSE sequence. -- Highlights: •We investigate the potential of 3D FFE sequence to distinguish the grey-white of the cervical spinal cord at 3T MRI system. •We optimized The 3D FFE sequence was optimized to increase the grey-white contrast. •Utilizing medium TE for T2W and the shortest TR for reduction of susceptibility related artifacts and motion artefacts. •This technique may increase the confidence in the diagnosis of disease with the improved delineation of cord anatomy

  12. Contrast-enhanced 3D MRI of lung perfusion in children with cystic fibrosis - initial results

    This paper is a feasibility study of magnetic resonance imaging (MRI) of lung perfusion in children with cystic fibrosis (CF) using contrast-enhanced 3D MRI. Correlation assessment of perfusion changes with structural abnormalities. Eleven CF patients (9 f, 2 m; median age 16 years) were examined at 1.5 T. Morphology: HASTE coronal, transversal (TR/TE/α/ST: 600 ms/28 ms/180 /6 mm), breath-hold 18 s. Perfusion: Time-resolved 3D GRE pulse sequence (FLASH, TE/TR/α: 0.8/1.9 ms/40 ), parallel imaging (GRAPPA, PAT 2). Twenty-five data sets were acquired after intravenous injection of 0.1 mmol/kg body weight of gadodiamide, 3-5 ml/s. A total of 198 lung segments were analyzed by two radiologists in consensus and scored for morphological and perfusion changes. Statistical analysis was performed by Mantel-Haenszel chi-square test. Results showed that perfusion defects were observed in all patients and present in 80% of upper, and 39% of lower lobes. Normal lung parenchyma showed homogeneous perfusion (86%, P<0.0001). Severe morphological changes led to perfusion defects (97%, P<0.0001). Segments with moderate morphological changes showed normal (53%) or impaired perfusion (47%). In conclusion, pulmonary perfusion is easy to judge in segments with normal parenchyma or severe changes. In moderately damaged segments, MRI of lung perfusion may help to better assess actual functional impairment. Contrast-enhanced 3D MRI of lung perfusion has the potential for early vascular functional assessment and therapy control in CF patients. (orig.)

  13. Random-Profiles-Based 3D Face Recognition System

    Joongrock Kim

    2014-03-01

    Full Text Available In this paper, a noble nonintrusive three-dimensional (3D face modeling system for random-profile-based 3D face recognition is presented. Although recent two-dimensional (2D face recognition systems can achieve a reliable recognition rate under certain conditions, their performance is limited by internal and external changes, such as illumination and pose variation. To address these issues, 3D face recognition, which uses 3D face data, has recently received much attention. However, the performance of 3D face recognition highly depends on the precision of acquired 3D face data, while also requiring more computational power and storage capacity than 2D face recognition systems. In this paper, we present a developed nonintrusive 3D face modeling system composed of a stereo vision system and an invisible near-infrared line laser, which can be directly applied to profile-based 3D face recognition. We further propose a novel random-profile-based 3D face recognition method that is memory-efficient and pose-invariant. The experimental results demonstrate that the reconstructed 3D face data consists of more than 50 k 3D point clouds and a reliable recognition rate against pose variation.

  14. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction.

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-03-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localization because of the large effective volume of the 3D point spread function (PSF). The inability to precisely locate the emitters at a high density causes poor temporal resolution of localization-based superresolution technique and significantly limits its application in 3D live cell imaging. To address this problem, we developed a 3D high-density superresolution imaging platform that allows us to precisely locate the positions of emitters, even when they are significantly overlapped in three dimensional space. Our platform involves a multi-focus system in combination with astigmatic optics and an ℓ 1-Homotopy optimization procedure. To reduce the intrinsic bias introduced by the discrete formulation of compressed sensing, we introduced a debiasing step followed by a 3D weighted centroid procedure, which not only increases the localization accuracy, but also increases the computation speed of image reconstruction. We implemented our algorithms on a graphic processing unit (GPU), which speeds up processing 10 times compared with central processing unit (CPU) implementation. We tested our method with both simulated data and experimental data of fluorescently labeled microtubules and were able to reconstruct a 3D microtubule image with 1000 frames (512×512) acquired within 20 seconds. PMID:25798314

  15. 3D CAD model reconstruction of a human femur from MRI images

    Benaissa EL FAHIME

    2013-05-01

    Full Text Available Medical practice and life sciences take full advantage of progress in engineering disciplines, in particular the computer assisted placement technique in hip surgery. This paper describes the three dimensional model reconstruction of human femur from MRI images. The developed program enables to obtain digital shape of 3D femur recognized by all CAD software and allows an accurate placement of the femoral component. This technic provides precise measurement of implant alignment during hip resurfacing or total hip arthroplasty, thereby reducing the risk of component mal-positioning and femoral neck notching.

  16. Plaque characterization in ex vivo MRI evaluated by dense 3D correspondence with histology

    van Engelen, Arna; de Bruijne, Marleen; Klein, Stefan; Verhagen, Hence; Groen, Harald; Wentzel, Jolanda; van der Lugt, Aad; Niessen, Wiro

    2011-03-01

    Automatic quantification of carotid artery plaque composition is important in the development of methods that distinguish vulnerable from stable plaques. MRI has shown to be capable of imaging different components noninvasively. We present a new plaque classification method which uses 3D registration of histology data with ex vivo MRI data, using non-rigid registration, both for training and evaluation. This is more objective than previously presented methods, as it eliminates selection bias that is introduced when 2D MRI slices are manually matched to histological slices before evaluation. Histological slices of human atherosclerotic plaques were manually segmented into necrotic core, fibrous tissue and calcification. Classification of these three components was voxelwise evaluated. As features the intensity, gradient magnitude and Laplacian in four MRI sequences after different degrees of Gaussian smoothing, and the distances to the lumen and the outer vessel wall, were used. Performance of linear and quadratic discriminant classifiers for different combinations of features was evaluated. Best accuracy (72.5 +/- 7.7%) was reached with the linear classifier when all features were used. Although this was only a minor improvement to the accuracy of a classifier that only included the intensities and distance features (71.6 +/- 7.9%), the difference was statistically significant (paired t-test, p<0.05). Good sensitivity and specificity for calcification was reached (83% and 95% respectively), however, differentiation between fibrous (sensitivity 85%, specificity 60%) and necrotic tissue (sensitivity 49%, specificity 89%) was more difficult.

  17. Audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI

    The purpose of this study was to test the hypothesis that audiovisual (AV) biofeedback can improve image quality and reduce scan time for respiratory-gated 3D thoracic MRI. For five healthy human subjects respiratory motion guidance in MR scans was provided using an AV biofeedback system, utilizing real-time respiratory motion signals. To investigate the improvement of respiratory-gated 3D MR images between free breathing (FB) and AV biofeedback (AV), each subject underwent two imaging sessions. Respiratory-related motion artifacts and imaging time were qualitatively evaluated in addition to the reproducibility of external (abdominal) motion. In the results, 3D MR images in AV biofeedback showed more anatomic information such as a clear distinction of diaphragm, lung lobes and sharper organ boundaries. The scan time was reduced from 401±215 s in FB to 334±94 s in AV (p-value 0.36). The root mean square variation of the displacement and period of the abdominal motion was reduced from 0.4±0.22 cm and 2.8±2.5 s in FB to 0.1±0.15 cm and 0.9±1.3 s in AV (p-value of displacement <0.01 and p-value of period 0.12). This study demonstrated that audiovisual biofeedback improves image quality and reduces scan time for respiratory-gated 3D MRI. These results suggest that AV biofeedback has the potential to be a useful motion management tool in medical imaging and radiation therapy procedures.

  18. Inclined nanoimprinting lithography-based 3D nanofabrication

    We report a 'top–down' 3D nanofabrication approach combining non-conventional inclined nanoimprint lithography (INIL) with reactive ion etching (RIE), contact molding and 3D metal nanotransfer printing (nTP). This integration of processes enables the production and conformal transfer of 3D polymer nanostructures of varying heights to a variety of other materials including a silicon-based substrate, a silicone stamp and a metal gold (Au) thin film. The process demonstrates the potential of reduced fabrication cost and complexity compared to existing methods. Various 3D nanostructures in technologically useful materials have been fabricated, including symmetric and asymmetric nanolines, nanocircles and nanosquares. Such 3D nanostructures have potential applications such as angle-resolved photonic crystals, plasmonic crystals and biomimicking anisotropic surfaces. This integrated INIL-based strategy shows great promise for 3D nanofabrication in the fields of photonics, plasmonics and surface tribology

  19. Tablet-Based Interaction for Immersive 3D Data Exploration

    Lopez, David; Oehlberg, Lora; Doger, Candemir; Isenberg, Tobias

    2014-01-01

    Our overall vision is to enable researchers to explore 3D datasets with as much immersion as possible, arising both from visuals as well as from interaction . We therefore explore ways to combine an immersive large view of the 3D data with means to intuitively control this view with touch input on a separate mobile monoscopic tablet. This combination has the potential to increase people's acceptance of stereoscopic environments for 3D data visualization since--through touch-based interaction-...

  20. Review: Polymeric-Based 3D Printing for Tissue Engineering

    Wu, Geng-Hsi; Hsu, Shan-hui

    2015-01-01

    Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue ...

  1. 3D {sup 23}Na MRI of human skeletal muscle at 7 Tesla: initial experience

    Chang, Gregory; Wang, Ligong; Regatte, Ravinder R. [Center for Biomedical Imaging/Hospital for Joint Diseases, Department of Radiology, NYU Langone Medical Center, New York, NY (United States); Schweitzer, Mark E. [Ottawa General Hospital, Department of Diagnostic Imaging, Ottawa, ON (Canada)

    2010-08-15

    To evaluate healthy skeletal muscle pre- and post-exercise via 7 T {sup 23}Na MRI and muscle proton T{sub 2} mapping, and to evaluate diabetic muscle pre- and post-exercise via 7 T {sup 23}Na MRI. The calves of seven healthy subjects underwent imaging pre- and post-exercise via 7 T {sup 23}Na MRI (3D fast low angle shot, TR/TE = 80 ms/0.160 ms, 4 mm x 4 mm x 4 mm) and 1 week later by {sup 1}H MRI (multiple spin-echo sequence, TR/TE = 3,000 ms/15-90 ms). Four type 2 diabetics also participated in the {sup 23}Na MRI protocol. Pre- and post-exercise sodium signal intensity (SI) and proton T{sub 2} relaxation values were measured/calculated for soleus (S), gastrocnemius (G), and a control, tibialis anterior (TA). Two-tailed t tests were performed. In S/G in healthy subjects post-exercise, sodium SI increased 8-13% (p < 0.03), then decreased (t{sub 1/2} = 22 min), and {sup 1}H T{sub 2} values increased 12-17% (p < 0.03), then decreased (t{sub 1/2} = 12-15 min). In TA, no significant changes in sodium SI or {sup 1}H T{sub 2} values were seen (-2.4 to 1%, p > 0.17). In S/G in diabetics, sodium SI increased 10-11% (p < 0.04), then decreased (t{sub 1/2} = 27-37 min) without significant change in the TA SI (-3.6%, p = 0.066). It is feasible to evaluate skeletal muscle via 3D {sup 23}Na MRI at 7 T. Post-exercise muscle {sup 1}H T{sub 2} values return to baseline more rapidly than sodium SI. Diabetics may demonstrate delayed muscle sodium SI recovery compared with healthy subjects. (orig.)

  2. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-01-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localiza...

  3. Octree-based Robust Watermarking for 3D Model

    Su Cai

    2011-02-01

    Full Text Available Three robust blind watermarking methods of 3D models based on Octree are proposed in this paper: OTC-W, OTP-W and Zero-W. Primary Component Analysis and Octree partition are used on 3D meshes. A scrambled binary image for OTC-W and a scrambled RGB image for OTP-W are separately embedded adaptively into the single child nodes at the bottom level of Octree structure. The watermark can be extracted without the original image and 3D model. Those two methods have high embedding capacity for 3D meshes. Meanwhile, they are robust against geometric transformation (like translation, rotation, uniform scaling and vertex reordering attacks. For Zero-W, higher nodes of Octree are used to construct ‘Zero-watermark’, which can resist simplification, noise and remeshing attacks. All those three methods are fit for 3D point cloud data and arbitrary 3D meshes.Three robust blind watermarking methods of 3D models based on Octree are proposed in this paper: OTC-W, OTP-W and Zero-W. Primary Component Analysis and Octree partition are used on 3D meshes. A scrambled binary image for OTC-W and a scrambled RGB image for OTP-W are separately embedded adaptively into the single child nodes at the bottom level of Octree structure. The watermark can be extracted without the original image and 3D model. Those two methods have high embedding capacity for 3D meshes. Meanwhile, they are robust against geometric transformation (like translation, rotation, uniform scaling and vertex reordering attacks. For Zero-W, higher nodes of Octree are used to construct ‘Zero-watermark’, which can resist simplification, noise and remeshing attacks. All those three methods are fit for 3D point cloud data and arbitrary 3D meshes.

  4. 3D Wavelet-Based Filter and Method

    Moss, William C.; Haase, Sebastian; Sedat, John W.

    2008-08-12

    A 3D wavelet-based filter for visualizing and locating structural features of a user-specified linear size in 2D or 3D image data. The only input parameter is a characteristic linear size of the feature of interest, and the filter output contains only those regions that are correlated with the characteristic size, thus denoising the image.

  5. Image based 3D city modeling : Comparative study

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  6. Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI

    Mogalle, Katja; Perez-Rovira, Adria; Ciet, Pierluigi; Wens, Stephan C. A.; van Doorn, Pieter A.; Tiddens, Harm A. W. M.; van der Ploeg, Ans T.; de Bruijne, Marleen

    2016-01-01

    Background Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness. Methods The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle. Results Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls) of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls. Conclusion Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response. PMID:27391236

  7. Combining supine MRI and 3D optical scanning for improved surgical planning of breast conserving surgeries

    Pallone, Matthew J.; Poplack, Steven P.; Barth, Richard J., Jr.; Paulsen, Keith D.

    2012-02-01

    Image-guided wire localization is the current standard of care for the excision of non-palpable carcinomas during breast conserving surgeries (BCS). The efficacy of this technique depends upon the accuracy of wire placement, maintenance of the fixed wire position (despite patient movement), and the surgeon's understanding of the spatial relationship between the wire and tumor. Notably, breast shape can vary significantly between the imaging and surgical positions. Despite this method of localization, re-excision is needed in approximately 30% of patients due to the proximity of cancer to the specimen margins. These limitations make wire localization an inefficient and imprecise procedure. Alternatively, we investigate a method of image registration and finite element (FE) deformation which correlates preoperative supine MRIs with 3D optical scans of the breast surface. MRI of the breast can accurately define the extents of very small cancers. Furthermore, supine breast MR reduces the amount of tissue deformation between the imaging and surgical positions. At the time of surgery, the surface contour of the breast may be imaged using a handheld 3D laser scanner. With the MR images segmented by tissue type, the two scans are approximately registered using fiducial markers present in both acquisitions. The segmented MRI breast volume is then deformed to match the optical surface using a FE mechanical model of breast tissue. The resulting images provide the surgeon with 3D views and measurements of the tumor shape, volume, and position within the breast as it appears during surgery which may improve surgical guidance and obviate the need for wire localization.

  8. 3D MRI findings of anterior cruciate ligament reconstruction at follow-up

    Objective: To investigate the postoperative 3D MRI appearances and their evolvement patterns of ACL grafts and bone tunnels at follow-up. Methods: There were 2,6 double bundles ACL reconstructions and 16 single bundle ACL reconstructions, and a total of 56 follow-up 3D MR Imaging. MR images were reconstructed with MPR technique to evaluate grafts, bone tunnels, fixers and associated complications. Proportions of grafts with hypointensity or hyperintensity and occurrence rates of marrow edema around bone tunnels were calculated respectively among groups of different periods after operation. Results: There were 2, 4 grafts of hypointensity and 32 grafts of hyperintensity. Grafts of 2 cases were suspended with cross pins within femoral tunnels, graft of 1 case was suspended with an endobutton within the femoral tunnel, and grafts of other sites were fixed with interference screws. In the three periods as 3 months, 6 to 9 months and over 12 months after cruciate ligament reconstruction, proportions of hypointensive grafts were 20/25, 0/14 and 4/10 respectively, while proportions of hyperintensive grafts were 5/25, 14/14 and 6/10 respectively, occurrence proportions of marrow edema around bone tunnels were 54/54, 10/32 and 4/26 respectively. There was 1 tear graft, 4 tibial tunnels placed anteriorly with ACL graft impingement on the intercondylar roof, 3 femoral tunnels placed anteriorly, and 2 bone tunnels with mismatching interference screws. Conclusion: 3D MRI can accurately demonstrate the state of ACL grafts, bone tunnels, fixers and associated complications. Intensity of grafts presented a rise and reduce pattern after operation. (authors)

  9. Quantification of Diaphragm Mechanics in Pompe Disease Using Dynamic 3D MRI.

    Katja Mogalle

    Full Text Available Diaphragm weakness is the main reason for respiratory dysfunction in patients with Pompe disease, a progressive metabolic myopathy affecting respiratory and limb-girdle muscles. Since respiratory failure is the major cause of death among adult patients, early identification of respiratory muscle involvement is necessary to initiate treatment in time and possibly prevent irreversible damage. In this paper we investigate the suitability of dynamic MR imaging in combination with state-of-the-art image analysis methods to assess respiratory muscle weakness.The proposed methodology relies on image registration and lung surface extraction to quantify lung kinematics during breathing. This allows for the extraction of geometry and motion features of the lung that characterize the independent contribution of the diaphragm and the thoracic muscles to the respiratory cycle.Results in 16 3D+t MRI scans (10 Pompe patients and 6 controls of a slow expiratory maneuver show that kinematic analysis from dynamic 3D images reveals important additional information about diaphragm mechanics and respiratory muscle involvement when compared to conventional pulmonary function tests. Pompe patients with severely reduced pulmonary function showed severe diaphragm weakness presented by minimal motion of the diaphragm. In patients with moderately reduced pulmonary function, cranial displacement of posterior diaphragm parts was reduced and the diaphragm dome was oriented more horizontally at full inspiration compared to healthy controls.Dynamic 3D MRI provides data for analyzing the contribution of both diaphragm and thoracic muscles independently. The proposed image analysis method has the potential to detect less severe diaphragm weakness and could thus be used to determine the optimal start of treatment in adult patients with Pompe disease in prospect of increased treatment response.

  10. 3D cardiac motion reconstruction from CT data and tagged MRI.

    Wang, Xiaoxu; Mihalef, Viorel; Qian, Zhen; Voros, Szilard; Metaxas, Dimitris

    2012-01-01

    In this paper we present a novel method for left ventricle (LV) endocardium motion reconstruction using high resolution CT data and tagged MRI. High resolution CT data provide anatomic details on the LV endocardial surface, such as the papillary muscle and trabeculae carneae. Tagged MRI provides better time resolution. The combination of these two imaging techniques can give us better understanding on left ventricle motion. The high resolution CT images are segmented with mean shift method and generate the LV endocardium mesh. The meshless deformable model built with high resolution endocardium surface from CT data fit to the tagged MRI of the same phase. 3D deformation of the myocardium is computed with the Lagrangian dynamics and local Laplacian deformation. The segmented inner surface of left ventricle is compared with the heart inner surface picture and show high agreement. The papillary muscles are attached to the inner surface with roots. The free wall of the left ventricle inner surface is covered with trabeculae carneae. The deformation of the heart wall and the papillary muscle in the first half of the cardiac cycle is presented. The motion reconstruction results are very close to the live heart video. PMID:23366825

  11. A Legendre orthogonal moment based 3D edge operator

    ZHANG Hui; SHU Huazhong; LUO Limin; J. L. Dillenseger

    2005-01-01

    This paper presents a new 3D edge operator based on Legendre orthogonal moments. This operator can be used to extract the edge of 3D object in any window size,with more accurate surface orientation and more precise surface location. It also has full geometry meaning. Process of calculation is considered in the moment based method.We can greatly speed up the computation by calculating out the masks in advance. We integrate this operator into our rendering of medical image data based on ray casting algorithm. Experimental results show that it is an effective 3D edge operator that is more accurate in position and orientation.

  12. Knowledge Base Approach for 3D Objects Detection in Point Clouds Using 3D Processing and Specialists Knowledge

    Ben Hmida, Helmi; Cruz, Christophe; Boochs, Frank; Nicolle, Christophe

    2013-01-01

    International audience This paper presents a knowledge-based detection of objects approach using the OWL ontology language, the Semantic Web Rule Language, and 3D processing built-ins aiming at combining geometrical analysis of 3D point clouds and specialist's knowledge. Here, we share our experience regarding the creation of 3D semantic facility model out of unorganized 3D point clouds. Thus, a knowledge-based detection approach of objects using the OWL ontology language is presented. Thi...

  13. Diagnostic imaging of the lumbar disc herniation for radiculopathy by 3D-MRI (MR-myelography)

    Taira, Gaku; Imakiire, Atsuhiro; Endo, Kenji [Tokyo Medical Coll. (Japan); Ichimaru, Katuji

    2002-02-01

    We have developed a new method of three-dimensional MRI (3D-MRI) which enables a stereoscopic view of the spinal cord and both sides of spinal nerve roots in one image. Anatomical study for normal subjects, the S1 angulations and length were significantly smaller than those of others. The S1 DRG was oval and was the largest. In a pathological study the use of 3D-MRI defects the signal changes following damage to the spinal nerve roots or ganglion in lumbar disc herniation. With regard to signal changes in damaged root ganglion, a good correlation between root compression and root inflammation was detected by experiments. We are currently examining the relationship between the damaged root ganglion, pain sensory disturbance. This study showed that the dorsal root ganglion plays an important role in sensory control of radiculopathy on 3D-MRI. (author)

  14. Diagnostic imaging of the lumbar disc herniation for radiculopathy by 3D-MRI (MR-myelography)

    We have developed a new method of three-dimensional MRI (3D-MRI) which enables a stereoscopic view of the spinal cord and both sides of spinal nerve roots in one image. Anatomical study for normal subjects, the S1 angulations and length were significantly smaller than those of others. The S1 DRG was oval and was the largest. In a pathological study the use of 3D-MRI defects the signal changes following damage to the spinal nerve roots or ganglion in lumbar disc herniation. With regard to signal changes in damaged root ganglion, a good correlation between root compression and root inflammation was detected by experiments. We are currently examining the relationship between the damaged root ganglion, pain sensory disturbance. This study showed that the dorsal root ganglion plays an important role in sensory control of radiculopathy on 3D-MRI. (author)

  15. Terahertz Quantum Cascade Laser Based 3D Imaging Project

    National Aeronautics and Space Administration — LongWave Photonics proposes a terahertz quantum-cascade laser based swept-source optical coherence tomography (THz SS-OCT) system for single-sided, 3D,...

  16. 3D Motion Parameters Determination Based on Binocular Sequence Images

    2006-01-01

    Exactly capturing three dimensional (3D) motion information of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision system and a method for determining 3D motion parameters of an object from binocular sequence images are introduced. The main steps include camera calibration, the matching of motion and stereo images, 3D feature point correspondences and resolving the motion parameters. Finally, the experimental results of acquiring the motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned method are presented.

  17. Powder-based 3D printing for bone tissue engineering.

    Brunello, G; Sivolella, S; Meneghello, R; Ferroni, L; Gardin, C; Piattelli, A; Zavan, B; Bressan, E

    2016-01-01

    Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed. PMID:27086202

  18. A Primitive-Based 3D Object Recognition System

    Dhawan, Atam P.

    1988-08-01

    A knowledge-based 3D object recognition system has been developed. The system uses the hierarchical structural, geometrical and relational knowledge in matching the 3D object models to the image data through pre-defined primitives. The primitives, we have selected, to begin with, are 3D boxes, cylinders, and spheres. These primitives as viewed from different angles covering complete 3D rotation range are stored in a "Primitive-Viewing Knowledge-Base" in form of hierarchical structural and relational graphs. The knowledge-based system then hypothesizes about the viewing angle and decomposes the segmented image data into valid primitives. A rough 3D structural and relational description is made on the basis of recognized 3D primitives. This description is now used in the detailed high-level frame-based structural and relational matching. The system has several expert and knowledge-based systems working in both stand-alone and cooperative modes to provide multi-level processing. This multi-level processing utilizes both bottom-up (data-driven) and top-down (model-driven) approaches in order to acquire sufficient knowledge to accept or reject any hypothesis for matching or recognizing the objects in the given image.

  19. Fast imaging of laboratory core floods using 3D compressed sensing RARE MRI

    Ramskill, N. P.; Bush, I.; Sederman, A. J.; Mantle, M. D.; Benning, M.; Anger, B. C.; Appel, M.; Gladden, L. F.

    2016-09-01

    Three-dimensional (3D) imaging of the fluid distributions within the rock is essential to enable the unambiguous interpretation of core flooding data. Magnetic resonance imaging (MRI) has been widely used to image fluid saturation in rock cores; however, conventional acquisition strategies are typically too slow to capture the dynamic nature of the displacement processes that are of interest. Using Compressed Sensing (CS), it is possible to reconstruct a near-perfect image from significantly fewer measurements than was previously thought necessary, and this can result in a significant reduction in the image acquisition times. In the present study, a method using the Rapid Acquisition with Relaxation Enhancement (RARE) pulse sequence with CS to provide 3D images of the fluid saturation in rock core samples during laboratory core floods is demonstrated. An objective method using image quality metrics for the determination of the most suitable regularisation functional to be used in the CS reconstructions is reported. It is shown that for the present application, Total Variation outperforms the Haar and Daubechies3 wavelet families in terms of the agreement of their respective CS reconstructions with a fully-sampled reference image. Using the CS-RARE approach, 3D images of the fluid saturation in the rock core have been acquired in 16 min. The CS-RARE technique has been applied to image the residual water saturation in the rock during a water-water displacement core flood. With a flow rate corresponding to an interstitial velocity of vi = 1.89 ± 0.03 ft day-1, 0.1 pore volumes were injected over the course of each image acquisition, a four-fold reduction when compared to a fully-sampled RARE acquisition. Finally, the 3D CS-RARE technique has been used to image the drainage of dodecane into the water-saturated rock in which the dynamics of the coalescence of discrete clusters of the non-wetting phase are clearly observed. The enhancement in the temporal resolution

  20. Automatic "pipeline" analysis of 3-D MRI data for clinical trials: application to multiple sclerosis.

    Zijdenbos, Alex P; Forghani, Reza; Evans, Alan C

    2002-10-01

    The quantitative analysis of magnetic resonance imaging (MRI) data has become increasingly important in both research and clinical studies aiming at human brain development, function, and pathology. Inevitably, the role of quantitative image analysis in the evaluation of drug therapy will increase, driven in part by requirements imposed by regulatory agencies. However, the prohibitive length of time involved and the significant intraand inter-rater variability of the measurements obtained from manual analysis of large MRI databases represent major obstacles to the wider application of quantitative MRI analysis. We have developed a fully automatic "pipeline" image analysis framework and have successfully applied it to a number of large-scale, multicenter studies (more than 1,000 MRI scans). This pipeline system is based on robust image processing algorithms, executed in a parallel, distributed fashion. This paper describes the application of this system to the automatic quantification of multiple sclerosis lesion load in MRI, in the context of a phase III clinical trial. The pipeline results were evaluated through an extensive validation study, revealing that the obtained lesion measurements are statistically indistinguishable from those obtained by trained human observers. Given that intra- and inter-rater measurement variability is eliminated by automatic analysis, this system enhances the ability to detect small treatment effects not readily detectable through conventional analysis techniques. While useful for clinical trial analysis in multiple sclerosis, this system holds widespread potential for applications in other neurological disorders, as well as for the study of neurobiology in general. PMID:12585710

  1. MR neurography with multiplanar reconstruction of 3D MRI datasets: an anatomical study and clinical applications

    Freund, Wolfgang; Aschoff, Andrik J.; Stuber, Gregor; Schmitz, Bernd [University Hospitals Ulm, Clinic for Diagnostic and Interventional Radiology, Ulm (Germany); Brinkmann, Alexander; Wagner, Florian; Dinse, Alexander [University Hospitals Ulm, Department of Anesthesiology, Ulm (Germany)

    2007-04-15

    Extracranial MR neurography has so far mainly been used with 2D datasets. We investigated the use of 3D datasets for peripheral neurography of the sciatic nerve. A total of 40 thighs (20 healthy volunteers) were examined with a coronally oriented magnetization-prepared rapid acquisition gradient echo sequence with isotropic voxels of 1 x 1 x 1 mm and a field of view of 500 mm. Anatomical landmarks were palpated and marked with MRI markers. After MR scanning, the sciatic nerve was identified by two readers independently in the resulting 3D dataset. In every volunteer, the sciatic nerve could be identified bilaterally over the whole length of the thigh, even in areas of close contact to isointense muscles. The landmark of the greater trochanter was falsely palpated by 2.2 cm, and the knee joint by 1 cm. The mean distance between the bifurcation of the sciatic nerve and the knee-joint gap was 6 cm ({+-}1.8 cm). The mean results of the two readers differed by 1-6%. With the described method of MR neurography, the sciatic nerve was depicted reliably and objectively in great anatomical detail over the whole length of the thigh. Important anatomical information can be obtained. The clinical applications of MR neurography for the brachial plexus and lumbosacral plexus/sciatic nerve are discussed. (orig.)

  2. Detailed Primitive-Based 3d Modeling of Architectural Elements

    Remondino, F.; Lo Buglio, D.; Nony, N.; De Luca, L.

    2012-07-01

    The article describes a pipeline, based on image-data, for the 3D reconstruction of building façades or architectural elements and the successive modeling using geometric primitives. The approach overcome some existing problems in modeling architectural elements and deliver efficient-in-size reality-based textured 3D models useful for metric applications. For the 3D reconstruction, an opensource pipeline developed within the TAPENADE project is employed. In the successive modeling steps, the user manually selects an area containing an architectural element (capital, column, bas-relief, window tympanum, etc.) and then the procedure fits geometric primitives and computes disparity and displacement maps in order to tie visual and geometric information together in a light but detailed 3D model. Examples are reported and commented.

  3. 3D Visual SLAM Based on Multiple Iterative Closest Point

    Chunguang Li; Chongben Tao; Guodong Liu

    2015-01-01

    With the development of novel RGB-D visual sensors, data association has been a basic problem in 3D Visual Simultaneous Localization and Mapping (VSLAM). To solve the problem, a VSLAM algorithm based on Multiple Iterative Closest Point (MICP) is presented. By using both RGB and depth information obtained from RGB-D camera, 3D models of indoor environment can be reconstructed, which provide extensive knowledge for mobile robots to accomplish tasks such as VSLAM and Human-Robot Interaction. Due...

  4. Contour-based 3d motion recovery while zooming

    Martínez Marroquín, Elisa; Torras Genís, Carme

    2003-01-01

    This paper considers the problem of 3D motion recovery from a sequence of monocular images while zooming. Unlike the common trend based on point matches, the proposed method relies on the deformation of an active contour fitted to a reference object. We derive the relation between the contour deformation and the 3D motion components, assuming time-varying focal length and principal point. This relation allows us to present a method to extract the rotation matrix and the scaled translation alo...

  5. 3D documentation and visualization of external injury findings by integration of simple photography in CT/MRI data sets (IprojeCT).

    Campana, Lorenzo; Breitbeck, Robert; Bauer-Kreuz, Regula; Buck, Ursula

    2016-05-01

    This study evaluated the feasibility of documenting patterned injury using three dimensions and true colour photography without complex 3D surface documentation methods. This method is based on a generated 3D surface model using radiologic slice images (CT) while the colour information is derived from photographs taken with commercially available cameras. The external patterned injuries were documented in 16 cases using digital photography as well as highly precise photogrammetry-supported 3D structured light scanning. The internal findings of these deceased were recorded using CT and MRI. For registration of the internal with the external data, two different types of radiographic markers were used and compared. The 3D surface model generated from CT slice images was linked with the photographs, and thereby digital true-colour 3D models of the patterned injuries could be created (Image projection onto CT/IprojeCT). In addition, these external models were merged with the models of the somatic interior. We demonstrated that 3D documentation and visualization of external injury findings by integration of digital photography in CT/MRI data sets is suitable for the 3D documentation of individual patterned injuries to a body. Nevertheless, this documentation method is not a substitution for photogrammetry and surface scanning, especially when the entire bodily surface is to be recorded in three dimensions including all external findings, and when precise data is required for comparing highly detailed injury features with the injury-inflicting tool. PMID:26496803

  6. The developing role of knee MRI in musculo-skeletal radiology: the progression to 3-D imaging

    The purpose of this paper, following a comprehensive and systematic review of the available literature, is to provide both a historical record of the development of knee MRI and outline its progression to new 'state of the art' three dimensional reconstruction techniques. while preliminary work has been done to qualitatively- explore the application of 3D knee MR in controlled research settings the true clinical value of such applications has not yet been clearly established. lt was found that in the absence of valid research findings, much of the reported work in this area relied heavily on both anecdotal evidence and hypothetical expressions of likelihood. Much work must still be done to validate the reliability and clinical usefulness of this new diagnostic tool. In following with the reports of previous authors, the likely benefits of a 3-D computer reconstructed model of the knee include improved display of complex anatomical relationships, clarification of anatomical structures, clear demonstration of anatomy/pathology for those unfamiliar with tomographic or sectional images,and reduced examination time. Work has also suggested that 3-D MR may allow accurate pre-surgical classification of lesions while facilitating operative planning and real time intra-operative navigation. Other areas of cutting edge research also include applications toward surgical robotics, simulated surgical procedures, tele surgery, bone and prosthesis modeling, and virtual endoscopy/arthroscopy One of the more practical potential benefits of 3-D image displays may lie in assisting the radiologist to communicate the appearance of normal anatomy or pathological processes to other medical staff likely to be less familiar with the interpretation of routine two dimensional images. Such a method may also prove useful in aiding clinicians to convey their diagnoses and means of treatment to patients. It is hoped that this review will provide a base point from which future work can be

  7. AR based ornament design system for 3D printing

    Hiroshi Aoki

    2015-01-01

    Full Text Available In recent years, 3D printers have become popular as a means of outputting geometries designed on CAD or 3D graphics systems. However, the complex user interfaces of standard 3D software can make it difficult for ordinary consumers to design their own objects. Furthermore, models designed on 3D graphics software often have geometrical problems that make them impossible to output on a 3D printer. We propose a novel AR (augmented reality 3D modeling system with an air-spray like interface. We also propose a new data structure (octet voxel for representing designed models in such a way that the model is guaranteed to be a complete solid. The target shape is based on a regular polyhedron, and the octet voxel representation is suitable for designing geometrical objects having the same symmetries as the base regular polyhedron. Finally, we conducted a user test and confirmed that users can intuitively design their own ornaments in a short time with a simple user interface.

  8. Validity and reliability of 3D US for the detection of erosions in patients with rheumatoid arthritis using MRI as the gold standard

    Ellegaard, K; Bliddal, H; Møller Døhn, U;

    2014-01-01

    PURPOSE: To test the reliability and validity of a 3D US erosion score in RA using MRI as the gold standard. MATERIALS AND METHODS: RA patients were examined with 3D US and 3 T MRI over the 2nd and 3rd metacarpophalangeal joints. 3D blocks were evaluated by two investigators. The erosions were es...

  9. Assessing cerebrospinal fluid flow connectivity using 3D gradient echo phase contrast velocity encoded MRI

    The aim of this study is to investigate the feasibility of using three-directional velocity encoded 3D gradient echo (GE) phase contrast (PC) imaging to assess cerebrospinal fluid (CSF) flow connectivity in the human brain. Five healthy volunteers were scanned using low velocity sensitivity (Venc = 0.04–0.05 m s−1). Flow–time curves were compared to standard 2D PC scans. The 3D data were used to reconstruct in vivo CSF flow volumes based on time-averaged phase-difference information, and the patency of the CSF flow pathways was assessed using nearest-neighbour connectivity. A pulsatile flow phantom was used to gauge the measurement accuracy of the CSF flow volumes at low flow velocities. Flow connectivity from the lateral ventricles down to the cisterna magna was successfully demonstrated in all volunteers. The phantom tests showed a good distinction between the flow cavities and the background noise. 3D PC imaging results in CSF flow waveforms with similar pulsatility but underestimated peak velocities compared to 2D PC data. 3D time-resolved velocity encoded GE imaging has successfully been applied to assess CSF flow connectivity in normal subjects

  10. A web-based 3D geological information visualization system

    Song, Renbo; Jiang, Nan

    2013-03-01

    Construction of 3D geological visualization system has attracted much more concern in GIS, computer modeling, simulation and visualization fields. It not only can effectively help geological interpretation and analysis work, but also can it can help leveling up geosciences professional education. In this paper, an applet-based method was introduced for developing a web-based 3D geological information visualization system. The main aims of this paper are to explore a rapid and low-cost development method for constructing a web-based 3D geological system. First, the borehole data stored in Excel spreadsheets was extracted and then stored in SQLSERVER database of a web server. Second, the JDBC data access component was utilized for providing the capability of access the database. Third, the user interface was implemented with applet component embedded in JSP page and the 3D viewing and querying functions were implemented with PickCanvas of Java3D. Last, the borehole data acquired from geological survey were used for test the system, and the test results has shown that related methods of this paper have a certain application values.

  11. Decreased 3D observer variation with matched CT-MRI, for target delineation in Nasopharynx cancer

    Kaanders Johannes HAM

    2010-03-01

    Full Text Available Abstract Purpose To determine the variation in target delineation of nasopharyngeal carcinoma and the impact of measures to minimize this variation. Materials and methods For ten nasopharyngeal cancer patients, ten observers each delineated the Clinical Target Volume (CTV and the CTV elective. After 3D analysis of the delineated volumes, a second delineation was performed. This implied improved delineation instructions, a combined delineation on CT and co-registered MRI, forced use of sagittal reconstructions, and an on-line anatomical atlas. Results Both for the CTV and the CTV elective delineations, the 3D SD decreased from Phase 1 to Phase 2, from 4.4 to 3.3 mm for the CTV and from 5.9 to 4.9 mm for the elective. There was an increase agreement, where the observers intended to delineate the same structure, from 36 to 64 surface % (p = 0.003 for the CTV and from 17 to 59% (p = 0.004 for the elective. The largest variations were at the caudal border of the delineations but these were smaller when an observer utilized the sagittal window. Hence, the use of sagittal side windows was enforced in the second phase and resulted in a decreased standard deviation for this area from 7.7 to 3.3 mm (p = 0.001 for the CTV and 7.9 to 5.6 mm (p = 0.03 for the CTV elective. Discussion Attempts to decrease the variation need to be tailored to the specific causes of the variation. Use of delineation instructions multimodality imaging, the use of sagittal windows and an on-line atlas result in a higher agreement on the intended target.

  12. Decreased 3D observer variation with matched CT-MRI, for target delineation in Nasopharynx cancer

    To determine the variation in target delineation of nasopharyngeal carcinoma and the impact of measures to minimize this variation. For ten nasopharyngeal cancer patients, ten observers each delineated the Clinical Target Volume (CTV) and the CTV elective. After 3D analysis of the delineated volumes, a second delineation was performed. This implied improved delineation instructions, a combined delineation on CT and co-registered MRI, forced use of sagittal reconstructions, and an on-line anatomical atlas. Both for the CTV and the CTV elective delineations, the 3D SD decreased from Phase 1 to Phase 2, from 4.4 to 3.3 mm for the CTV and from 5.9 to 4.9 mm for the elective. There was an increase agreement, where the observers intended to delineate the same structure, from 36 to 64 surface % (p = 0.003) for the CTV and from 17 to 59% (p = 0.004) for the elective. The largest variations were at the caudal border of the delineations but these were smaller when an observer utilized the sagittal window. Hence, the use of sagittal side windows was enforced in the second phase and resulted in a decreased standard deviation for this area from 7.7 to 3.3 mm (p = 0.001) for the CTV and 7.9 to 5.6 mm (p = 0.03) for the CTV elective. Attempts to decrease the variation need to be tailored to the specific causes of the variation. Use of delineation instructions multimodality imaging, the use of sagittal windows and an on-line atlas result in a higher agreement on the intended target

  13. 3D MRI of impaired hyperpolarized 129Xe uptake in a rat model of pulmonary fibrosis.

    Cleveland, Zackary I; Virgincar, Rohan S; Qi, Yi; Robertson, Scott H; Degan, Simone; Driehuys, Bastiaan

    2014-12-01

    A variety of pulmonary pathologies, in particular interstitial lung diseases, are characterized by thickening of the pulmonary blood-gas barrier, and this thickening results in reduced gas exchange. Such diffusive impairment is challenging to quantify spatially, because the distributions of the metabolically relevant gases (CO2 and O2) cannot be detected directly within the lungs. Hyperpolarized (HP) (129)Xe is a promising surrogate for these metabolic gases, because MR spectroscopy and imaging allow gaseous alveolar (129)Xe to be detected separately from (129)Xe dissolved in the red blood cells (RBCs) and the adjacent tissues, which comprise blood plasma and lung interstitium. Because (129)Xe reaches the RBCs by diffusing across the same barrier tissues (blood plasma and interstitium) as O2, barrier thickening will delay (129)Xe transit and, thus, reduce RBC-specific (129)Xe MR signal. Here we have exploited these properties to generate 3D, MR images of (129)Xe uptake by the RBCs in two groups of rats. In the experimental group, unilateral fibrotic injury was generated prior to imaging by instilling bleomycin into one lung. In the control group, a unilateral sham instillation of saline was performed. Uptake of (129)Xe by the RBCs, quantified as the fraction of RBC signal relative to total dissolved (129)Xe signal, was significantly reduced (P = 0.03) in the injured lungs of bleomycin-treated animals. In contrast, no significant difference (P = 0.56) was observed between the saline-treated and untreated lungs of control animals. Together, these results indicate that 3D MRI of HP (129)Xe dissolved in the pulmonary tissues can provide useful biomarkers of impaired diffusive gas exchange resulting from fibrotic thickening. PMID:24816478

  14. Deep MRI brain extraction: A 3D convolutional neural network for skull stripping.

    Kleesiek, Jens; Urban, Gregor; Hubert, Alexander; Schwarz, Daniel; Maier-Hein, Klaus; Bendszus, Martin; Biller, Armin

    2016-04-01

    Brain extraction from magnetic resonance imaging (MRI) is crucial for many neuroimaging workflows. Current methods demonstrate good results on non-enhanced T1-weighted images, but struggle when confronted with other modalities and pathologically altered tissue. In this paper we present a 3D convolutional deep learning architecture to address these shortcomings. In contrast to existing methods, we are not limited to non-enhanced T1w images. When trained appropriately, our approach handles an arbitrary number of modalities including contrast-enhanced scans. Its applicability to MRI data, comprising four channels: non-enhanced and contrast-enhanced T1w, T2w and FLAIR contrasts, is demonstrated on a challenging clinical data set containing brain tumors (N=53), where our approach significantly outperforms six commonly used tools with a mean Dice score of 95.19. Further, the proposed method at least matches state-of-the-art performance as demonstrated on three publicly available data sets: IBSR, LPBA40 and OASIS, totaling N=135 volumes. For the IBSR (96.32) and LPBA40 (96.96) data set the convolutional neuronal network (CNN) obtains the highest average Dice scores, albeit not being significantly different from the second best performing method. For the OASIS data the second best Dice (95.02) results are achieved, with no statistical difference in comparison to the best performing tool. For all data sets the highest average specificity measures are evaluated, whereas the sensitivity displays about average results. Adjusting the cut-off threshold for generating the binary masks from the CNN's probability output can be used to increase the sensitivity of the method. Of course, this comes at the cost of a decreased specificity and has to be decided application specific. Using an optimized GPU implementation predictions can be achieved in less than one minute. The proposed method may prove useful for large-scale studies and clinical trials. PMID:26808333

  15. 3D Medical Image Segmentation Based on Rough Set Theory

    CHEN Shi-hao; TIAN Yun; WANG Yi; HAO Chong-yang

    2007-01-01

    This paper presents a method which uses multiple types of expert knowledge together in 3D medical image segmentation based on rough set theory. The focus of this paper is how to approximate a ROI (region of interest) when there are multiple types of expert knowledge. Based on rough set theory, the image can be split into three regions:positive regions; negative regions; boundary regions. With multiple knowledge we refine ROI as an intersection of all of the expected shapes with single knowledge. At last we show the results of implementing a rough 3D image segmentation and visualization system.

  16. MUTUAL INFORMATION BASED 3D NON-RIGID REGISTRATION OF CT/MR ABDOMEN IMAGES

    2001-01-01

    A mutual information based 3D non-rigid registration approach was proposed for the registration of deformable CT/MR body abdomen images. The Parzen Windows Density Estimation (PWDE) method is adopted to calculate the mutual information between the two modals of CT and MRI abdomen images. By maximizing MI between the CT and MR volume images, the overlapping part of them reaches the biggest, which means that the two body images of CT and MR matches best to each other. Visible Human Project (VHP) Male abdomen CT and MRI Data are used as experimental data sets. The experimental results indicate that this approach of non-rigid 3D registration of CT/MR body abdominal images can be achieved effectively and automatically, without any prior processing procedures such as segmentation and feature extraction, but has a main drawback of very long computation time. Key words: medical image registration; multi-modality; mutual information; non-rigid; Parzen window density estimation

  17. Design and development of a 3D cadastral prototype based on the LADM and 3D topology

    Ying, S.; Guo, R.; Li, L.; Van Oosterom, P.J.M.; Ledoux, H.; Stoter, J.E.

    2011-01-01

    In this paper the design and development of a prototype 3D Cadastral system will be presented. The key aspects of this system are that the model is based on Land Administration Domain Model (LADM) and that the spatial profile is based on a full 3D topological structure. The prototype development sta

  18. Characteristics of neurovascular compression in facial neuralgia patients by 3D high-resolution MRI and fusion technology

    Zi-Yi Guo; Jing Chen; Guang Yang; Qian-Yu Tang; Cai-Xiang Chen; Shui-Xi Fu; Dan Yu

    2012-01-01

    Objective: To evaluate the anatomical characteristics and patterns of neurovascular compression in patients suffering trigeminal neuralgia, using 3D high-resolution magnetic resonance imaging methods and fusion technologies. Methods: The analysis of the anatomy of the facial nerve, brain stem and the vascular structures related to this nerve was made in 100 consecutive patients for TN. 3D high resolution MRI studies (3D SPGR, T1 enhanced 3D MP-RAGE and T2/T1 3D FIESTA) simultaneous visualization were used to assessed using the software 3D DOCTOR. Results: In 93 patients (93%), there were one or several locals of neurovascular compression (NVC). The superior cerebellar artery was involved in 71 cases (76%), the other vessels including the antero-inferior cerebellar artery, the basilar artery, the vertebral artery, and some venous structures. The mean distance between NVC and nerve origin site in the brainstem was (3.76 ± 2.90) mm). In 39 patients (42%), the vascular compression was located proximally and in 42 (45%) the compression was located distally. Nerve dislocation or distortion by the vessel was observed in 30 cases (32%). Conclusions: This 3D high resolution MRI and image fusion technology could be useful for diagnostic and therapeutic decisions in TN.

  19. 3D printer as fixed equipment of MRI used in medical rescue%3D 打印技术在医疗救援中的应用

    刘志超; 杨炯; 王晓枫; 刘海峰

    2014-01-01

    Objective To manufacture a model or an auxiliary medical appliance by 3D printing technology,to make diagnosis and treatment of medical rescue process intuitive,convenient and accurate.Methods Using the 3D printing device of MRI system and FDM technology, the thermoplastic material under the control of the computer, the rapid production of various dies and auxiliary medi-cal appliances.Results Using the 3D printing device equipped in a vehicle with mounted MRI system can not only make the RF re-ceiving coil mould, also can be applied to the medical rescue in preoperative planning, intraoperative navigation, customized operation auxiliary instrumentand, and custom-made prosthesis in actual rescue scene.Conclusions 3D printer as matching equipment of MRI system plays an important role in the clinical diagnosis and therapy in the rescue scene.%目的:通过3D打印技术制作实物模型或医疗辅助器械,使医疗救援过程中的诊治方法更加直观化、便捷化、精确化。方法利用车载式磁共振成像系统配套装备的3D打印设备,借助熔融沉积制造( fused deposition modeling,FDM)技术,使用热塑性材料在计算机的控制下,快速制作各种实物模具和医疗辅助器械。结果利用车载式MRI系统配备的3D打印设备不仅能够制作射频接收线圈模具,还可应用于医疗救援中术前策划、术中导航、定制手术辅助器械,以及定制假体等,满足救援现场需求。结论3D打印技术作为车载式MRI的配套设备在救援现场诊断及治疗方面可发挥重要作用。

  20. Image-driven, model-based 3D abdominal motion estimation for MR-guided radiotherapy

    Stemkens, Bjorn; Tijssen, Rob H. N.; de Senneville, Baudouin Denis; Lagendijk, Jan J. W.; van den Berg, Cornelis A. T.

    2016-07-01

    Respiratory motion introduces substantial uncertainties in abdominal radiotherapy for which traditionally large margins are used. The MR-Linac will open up the opportunity to acquire high resolution MR images just prior to radiation and during treatment. However, volumetric MRI time series are not able to characterize 3D tumor and organ-at-risk motion with sufficient temporal resolution. In this study we propose a method to estimate 3D deformation vector fields (DVFs) with high spatial and temporal resolution based on fast 2D imaging and a subject-specific motion model based on respiratory correlated MRI. In a pre-beam phase, a retrospectively sorted 4D-MRI is acquired, from which the motion is parameterized using a principal component analysis. This motion model is used in combination with fast 2D cine-MR images, which are acquired during radiation, to generate full field-of-view 3D DVFs with a temporal resolution of 476 ms. The geometrical accuracies of the input data (4D-MRI and 2D multi-slice acquisitions) and the fitting procedure were determined using an MR-compatible motion phantom and found to be 1.0–1.5 mm on average. The framework was tested on seven healthy volunteers for both the pancreas and the kidney. The calculated motion was independently validated using one of the 2D slices, with an average error of 1.45 mm. The calculated 3D DVFs can be used retrospectively for treatment simulations, plan evaluations, or to determine the accumulated dose for both the tumor and organs-at-risk on a subject-specific basis in MR-guided radiotherapy.

  1. 3-D carotid multi-region MRI segmentation by globally optimal evolution of coupled surfaces.

    Ukwatta, Eranga; Yuan, Jing; Rajchl, Martin; Qiu, Wu; Tessier, David; Fenster, Aaron

    2013-04-01

    In this paper, we propose a novel global optimization based 3-D multi-region segmentation algorithm for T1-weighted black-blood carotid magnetic resonance (MR) images. The proposed algorithm partitions a 3-D carotid MR image into three regions: wall, lumen, and background. The algorithm performs such partitioning by simultaneously evolving two coupled 3-D surfaces of carotid artery adventitia boundary (AB) and lumen-intima boundary (LIB) while preserving their anatomical inter-surface consistency such that the LIB is always located within the AB. In particular, we show that the proposed algorithm results in a fully time implicit scheme that propagates the two linearly ordered surfaces of the AB and LIB to their globally optimal positions during each discrete time frame by convex relaxation. In this regard, we introduce the continuous max-flow model and prove its duality/equivalence to the convex relaxed optimization problem with respect to each evolution step. We then propose a fully parallelized continuous max-flow-based algorithm, which can be readily implemented on a GPU to achieve high computational efficiency. Extensive experiments, with four users using 12 3T MR and 26 1.5T MR images, demonstrate that the proposed algorithm yields high accuracy and low operator variability in computing vessel wall volume. In addition, we show the algorithm outperforms previous methods in terms of high computational efficiency and robustness with fewer user interactions. PMID:23303689

  2. Optical 3D watermark based digital image watermarking for telemedicine

    Li, Xiao Wei; Kim, Seok Tae

    2013-12-01

    Region of interest (ROI) of a medical image is an area including important diagnostic information and must be stored without any distortion. This algorithm for application of watermarking technique for non-ROI of the medical image preserving ROI. The paper presents a 3D watermark based medical image watermarking scheme. In this paper, a 3D watermark object is first decomposed into 2D elemental image array (EIA) by a lenslet array, and then the 2D elemental image array data is embedded into the host image. The watermark extraction process is an inverse process of embedding. The extracted EIA through the computational integral imaging reconstruction (CIIR) technique, the 3D watermark can be reconstructed. Because the EIA is composed of a number of elemental images possesses their own perspectives of a 3D watermark object. Even though the embedded watermark data badly damaged, the 3D virtual watermark can be successfully reconstructed. Furthermore, using CAT with various rule number parameters, it is possible to get many channels for embedding. So our method can recover the weak point having only one transform plane in traditional watermarking methods. The effectiveness of the proposed watermarking scheme is demonstrated with the aid of experimental results.

  3. Monocular model-based 3D tracking of rigid objects

    Lepetit, Vincent

    2014-01-01

    Many applications require tracking complex 3D objects. These include visual serving of robotic arms on specific target objects, Augmented Reality systems that require real time registration of the object to be augmented, and head tracking systems that sophisticated interfaces can use. Computer vision offers solutions that are cheap, practical and non-invasive. ""Monocular Model-Based 3D Tracking of Rigid Objects"" reviews the different techniques and approaches that have been developed by industry and research. First, important mathematical tools are introduced: camera representation, robust e

  4. Geometric Deformations Based on 3D Volume Morphing

    JIN Xiaogang; WAN Huagen; PENG Qunsheng

    2001-01-01

    This paper presents a new geometric deformation method based on 3D volume morphing by using a new concept called directional polar coordinate. The user specifies the source control object and the destination control object which act as the embedded spaces.The source and the destination control objects determine a 3D volume morphing which maps the space enclosed in the source control object to that of the destination control object. By embedding the object to be deformed into the source control object, the 3D volume morphing determines the deformed object automatically without the tiring moving of control points.Experiments show that this deformation model is efficient and intuitive, and it can achieve some deformation effects which are difficult to achieve for traditional methods.

  5. Robust model-based 3d/3D fusion using sparse matching for minimally invasive surgery.

    Neumann, Dominik; Grbic, Sasa; John, Matthias; Navab, Nassir; Hornegger, Joachim; Ionasec, Razvan

    2013-01-01

    Classical surgery is being disrupted by minimally invasive and transcatheter procedures. As there is no direct view or access to the affected anatomy, advanced imaging techniques such as 3D C-arm CT and C-arm fluoroscopy are routinely used for intra-operative guidance. However, intra-operative modalities have limited image quality of the soft tissue and a reliable assessment of the cardiac anatomy can only be made by injecting contrast agent, which is harmful to the patient and requires complex acquisition protocols. We propose a novel sparse matching approach for fusing high quality pre-operative CT and non-contrasted, non-gated intra-operative C-arm CT by utilizing robust machine learning and numerical optimization techniques. Thus, high-quality patient-specific models can be extracted from the pre-operative CT and mapped to the intra-operative imaging environment to guide minimally invasive procedures. Extensive quantitative experiments demonstrate that our model-based fusion approach has an average execution time of 2.9 s, while the accuracy lies within expert user confidence intervals. PMID:24505663

  6. 3D ear identification based on sparse representation.

    Lin Zhang

    Full Text Available Biometrics based personal authentication is an effective way for automatically recognizing, with a high confidence, a person's identity. Recently, 3D ear shape has attracted tremendous interests in research field due to its richness of feature and ease of acquisition. However, the existing ICP (Iterative Closet Point-based 3D ear matching methods prevalent in the literature are not quite efficient to cope with the one-to-many identification case. In this paper, we aim to fill this gap by proposing a novel effective fully automatic 3D ear identification system. We at first propose an accurate and efficient template-based ear detection method. By utilizing such a method, the extracted ear regions are represented in a common canonical coordinate system determined by the ear contour template, which facilitates much the following stages of feature extraction and classification. For each extracted 3D ear, a feature vector is generated as its representation by making use of a PCA-based local feature descriptor. At the stage of classification, we resort to the sparse representation based classification approach, which actually solves an l1-minimization problem. To the best of our knowledge, this is the first work introducing the sparse representation framework into the field of 3D ear identification. Extensive experiments conducted on a benchmark dataset corroborate the effectiveness and efficiency of the proposed approach. The associated Matlab source code and the evaluation results have been made publicly online available at http://sse.tongji.edu.cn/linzhang/ear/srcear/srcear.htm.

  7. Probabilistic reasoning for assembly-based 3D modeling

    Chaudhuri, Siddhartha

    2011-01-01

    Assembly-based modeling is a promising approach to broadening the accessibility of 3D modeling. In assembly-based modeling, new models are assembled from shape components extracted from a database. A key challenge in assembly-based modeling is the identification of relevant components to be presented to the user. In this paper, we introduce a probabilistic reasoning approach to this problem. Given a repository of shapes, our approach learns a probabilistic graphical model that encodes semantic and geometric relationships among shape components. The probabilistic model is used to present components that are semantically and stylistically compatible with the 3D model that is being assembled. Our experiments indicate that the probabilistic model increases the relevance of presented components. © 2011 ACM.

  8. 3D face recognition with asymptotic cones based principal curvatures

    Tang, Yinhang

    2015-05-01

    The classical curvatures of smooth surfaces (Gaussian, mean and principal curvatures) have been widely used in 3D face recognition (FR). However, facial surfaces resulting from 3D sensors are discrete meshes. In this paper, we present a general framework and define three principal curvatures on discrete surfaces for the purpose of 3D FR. These principal curvatures are derived from the construction of asymptotic cones associated to any Borel subset of the discrete surface. They describe the local geometry of the underlying mesh. First two of them correspond to the classical principal curvatures in the smooth case. We isolate the third principal curvature that carries out meaningful geometric shape information. The three principal curvatures in different Borel subsets scales give multi-scale local facial surface descriptors. We combine the proposed principal curvatures with the LNP-based facial descriptor and SRC for recognition. The identification and verification experiments demonstrate the practicability and accuracy of the third principal curvature and the fusion of multi-scale Borel subset descriptors on 3D face from FRGC v2.0.

  9. Vascular centerline extraction in 3D MR angiograms for phase contrast MRI blood flow measurement

    Hernandez Hoyos, M. [CREATIS, CNRS 5515 et INSERM U630 Research Unit, INSA de Lyon, 69 - Villeurbanne (France); Universidad de los Andes, Bogota (Colombia). Grupo Imagine, Grupo de Ingenieria Biomedica; Orlowski, P.; Piatkowska-Janko, E.; Bogorodzki, P. [Warsaw Univ. of Tech. (Poland). ZEJM-BINSK, Inst. of Radioelectronics; Orkisz, M. [CREATIS, CNRS 5515 et INSERM U630 Research Unit, INSA de Lyon, 69 - Villeurbanne (France)

    2006-03-15

    The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction, multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment between its normal vector and the centerlines' tangent vectors. The method was evaluated on a phantom and on 35 patients, by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries. In the phantom, difference of orientation and of height between known and calculated planes was 1.2 and 2.5 mm, respectively. In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12 per artery. Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA. (orig.)

  10. Vascular centerline extraction in 3D MR angiograms for phase contrast MRI blood flow measurement

    The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction, multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment between its normal vector and the centerlines' tangent vectors. The method was evaluated on a phantom and on 35 patients, by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries. In the phantom, difference of orientation and of height between known and calculated planes was 1.2 and 2.5 mm, respectively. In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12 per artery. Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA. (orig.)

  11. Early survival prediction after intra-arterial therapies: a 3D quantitative MRI assessment of tumour response after TACE or radioembolization of colorectal cancer metastases to the liver

    Chapiro, Julius; Savic, Lynn Jeanette [The Johns Hopkins Hospital, Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology, Baltimore, MD (United States); Charite Universitaetsmedizin, Department of Diagnostic and Interventional Radiology, Berlin (Germany); Duran, Rafael; Schernthaner, Ruediger; Wang, Zhijun; Geschwind, Jean-Francois [The Johns Hopkins Hospital, Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology, Baltimore, MD (United States); Lin, MingDe [The Johns Hopkins Hospital, Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology, Baltimore, MD (United States); U/S Imaging and Interventions (UII), Philips Research North America, Briarcliff Manor, NY (United States); Lesage, David [Philips Research, Medisys, Suresnes (France)

    2015-07-15

    This study evaluated the predictive role of 1D, 2D and 3D quantitative, enhancement-based MRI regarding overall survival (OS) in patients with colorectal liver metastases (CLM) following intra-arterial therapies (IAT). This retrospective analysis included 29 patients who underwent transarterial chemoembolization (TACE) or radioembolization and received MRI within 6 weeks after therapy. Tumour response was assessed using 1D and 2D criteria (such as European Association for the Study of the Liver guidelines [EASL] and modified Response Evaluation Criteria in Solid Tumors [mRECIST]). In addition, a segmentation-based 3D quantification of overall (volumetric [v] RECIST) and enhancing lesion volume (quantitative [q] EASL) was performed on portal venous phase MRI. Accordingly, patients were classified as responders (R) and non-responders (NR). Survival was evaluated using Kaplan-Meier analysis and compared using Cox proportional hazard ratios (HR). Only enhancement-based criteria identified patients as responders. EASL and mRECIST did not predict patient survival (P = 0.27 and P = 0.44, respectively). Using uni- and multivariate analysis, qEASL was identified as the sole predictor of patient survival (9.9 months for R, 6.9 months for NR; P = 0.038; HR 0.4). The ability of qEASL to predict survival early after IAT provides evidence for potential advantages of 3D quantitative tumour analysis. (orig.)

  12. Early survival prediction after intra-arterial therapies: a 3D quantitative MRI assessment of tumour response after TACE or radioembolization of colorectal cancer metastases to the liver

    Chapiro, Julius; Duran, Rafael; Lin, MingDe; Schernthaner, Rüdiger; Lesage, David; Wang, Zhijun; Savic, Lynn Jeanette; Geschwind, Jean-François

    2015-01-01

    Objectives This study evaluated the predictive role of 1D, 2D and 3D quantitative, enhancement-based MRI regarding overall survival (OS) in patients with colorectal liver metastases (CLM) following intra-arterial therapies (IAT). Methods This retrospective analysis included 29 patients who underwent transarterial chemoembolization (TACE) or radioembolization and received MRI within 6 weeks after therapy. Tumour response was assessed using 1D and 2D criteria (such as European Association for the Study of the Liver guidelines [EASL] and modified Response Evaluation Criteria in Solid Tumors [mRECIST]). In addition, a segmentation-based 3D quantification of overall (volumetric [v] RECIST) and enhancing lesion volume (quantitative [q] EASL) was performed on portal venous phase MRI. Accordingly, patients were classified as responders (R) and non-responders (NR). Survival was evaluated using Kaplan–Meier analysis and compared using Cox proportional hazard ratios (HR). Results Only enhancement-based criteria identified patients as responders. EASL and mRECIST did not predict patient survival (P = 0.27 and P = 0.44, respectively). Using uni- and multivariate analysis, qEASL was identified as the sole predictor of patient survival (9.9 months for R, 6.9 months for NR; P = 0.038; HR 0.4). Conclusion The ability of qEASL to predict survival early after IAT provides evidence for potential advantages of 3D quantitative tumour analysis. PMID:25636420

  13. A discriminative model-constrained EM approach to 3D MRI brain tissue classification and intensity non-uniformity correction

    We describe a fully automated method for tissue classification, which is the segmentation into cerebral gray matter (GM), cerebral white matter (WM), and cerebral spinal fluid (CSF), and intensity non-uniformity (INU) correction in brain magnetic resonance imaging (MRI) volumes. It combines supervised MRI modality-specific discriminative modeling and unsupervised statistical expectation maximization (EM) segmentation into an integrated Bayesian framework. While both the parametric observation models and the non-parametrically modeled INUs are estimated via EM during segmentation itself, a Markov random field (MRF) prior model regularizes segmentation and parameter estimation. Firstly, the regularization takes into account knowledge about spatial and appearance-related homogeneity of segments in terms of pairwise clique potentials of adjacent voxels. Secondly and more importantly, patient-specific knowledge about the global spatial distribution of brain tissue is incorporated into the segmentation process via unary clique potentials. They are based on a strong discriminative model provided by a probabilistic boosting tree (PBT) for classifying image voxels. It relies on the surrounding context and alignment-based features derived from a probabilistic anatomical atlas. The context considered is encoded by 3D Haar-like features of reduced INU sensitivity. Alignment is carried out fully automatically by means of an affine registration algorithm minimizing cross-correlation. Both types of features do not immediately use the observed intensities provided by the MRI modality but instead rely on specifically transformed features, which are less sensitive to MRI artifacts. Detailed quantitative evaluations on standard phantom scans and standard real-world data show the accuracy and robustness of the proposed method. They also demonstrate relative superiority in comparison to other state-of-the-art approaches to this kind of computational task: our method achieves average

  14. Rapidly 3D Texture Reconstruction Based on Oblique Photography

    ZHANG Chunsen

    2015-07-01

    Full Text Available This paper proposes a city texture fast reconstruction method based on aerial tilt image for reconstruction of three-dimensional city model. Based on the photogrammetry and computer vision theory and using the city building digital surface model obtained by prior treatment, through collinear equation calculation geometric projection of object and image space, to obtain the three-dimensional information and texture information of the structure and through certain the optimal algorithm selecting the optimal texture on the surface of the object, realize automatic extraction of the building side texture and occlusion handling of the dense building texture. The real image texture reconstruction results show that: the method to the 3D city model texture reconstruction has the characteristics of high degree of automation, vivid effect and low cost and provides a means of effective implementation for rapid and widespread real texture rapid reconstruction of city 3D model.

  15. 3-D model-based tracking for UAV indoor localization.

    Teulière, Céline; Marchand, Eric; Eck, Laurent

    2015-05-01

    This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights. PMID:25099967

  16. Development Of 3D Woven Fabric Based Pressure Switch

    Shaker Khubab

    2015-06-01

    Full Text Available This paper introduces a 3D woven fabric-based approach for the development of pressure switch. A fabric substrate, being elastic and extendable is very useful in addition to its high breaking strength and low cost. The developed resistive-type switch is based on the multilayer interlock 3D fabrics. In the top and bottom layers, certain number of conductive yarns are woven separated by cotton yarns in both transversal and thickness direction. Application of pressure makes the layers of conductive yarn to come in contact, resulting in a short circuit, which may be recorded using multi-meters. Removing the pressure cause the connection points to separate away and it depends on the weave design. Such switch can be used as an on/off switch for usage in security systems, can be sewn into carpets and wearable garments for a number of purposes.

  17. Method for 3D Rendering Based on Intersection Image Display Which Allows Representation of Internal Structure of 3D objects

    Kohei Arai

    2013-01-01

    Method for 3D rendering based on intersection image display which allows representation of internal structure is proposed. The proposed method is essentially different from the conventional volume rendering based on solid model which allows representation of just surface of the 3D objects. By using afterimage, internal structure can be displayed through exchanging the intersection images with internal structure for the proposed method. Through experiments with CT scan images, the proposed met...

  18. GPU-accelerated 3-D model-based tracking

    Model-based approaches to tracking the pose of a 3-D object in video are effective but computationally demanding. While statistical estimation techniques, such as the particle filter, are often employed to minimize the search space, real-time performance remains unachievable on current generation CPUs. Recent advances in graphics processing units (GPUs) have brought massively parallel computational power to the desktop environment and powerful developer tools, such as NVIDIA Compute Unified Device Architecture (CUDA), have provided programmers with a mechanism to exploit it. NVIDIA GPUs' single-instruction multiple-thread (SIMT) programming model is well-suited to many computer vision tasks, particularly model-based tracking, which requires several hundred 3-D model poses to be dynamically configured, rendered, and evaluated against each frame in the video sequence. Using 6 degree-of-freedom (DOF) rigid hand tracking as an example application, this work harnesses consumer-grade GPUs to achieve real-time, 3-D model-based, markerless object tracking in monocular video.

  19. 3D MRI of non-Gaussian 3He gas diffusion in the rat lung

    Jacob, Richard E.; Laicher, Gernot; Minard, Kevin R.

    2007-10-01

    In 3He magnetic resonance images of pulmonary air spaces, the confining architecture of the parenchymal tissue results in a non-Gaussian distribution of signal phase that non-exponentially attenuates image intensity as diffusion weighting is increased. Here, two approaches previously used for the analysis of non-Gaussian effects in the lung are compared and related using diffusion-weighted 3He MR images of mechanically ventilated rats. One approach is model-based and was presented by Yablonskiy et al., while the other approach utilizes the second order decay contribution that is predicted from the cumulant expansion theorem. Total lung coverage is achieved using a hybrid 3D pulse sequence that combines conventional phase encoding with sparse radial sampling for efficient gas usage. This enables the acquisition of nine 3D images using a total of only ˜1 L of hyperpolarized 3He gas. Diffusion weighting ranges from 0 s/cm 2 to 40 s/cm 2. Results show that the non-Gaussian effects of 3He gas diffusion in healthy rat lungs are directly attributed to the anisotropic geometry of lung microstructure as predicted by the Yablonskiy model, and that quantitative analysis over the entire lung can be reliably repeated in time-course studies of the same animal.

  20. Automated scoring of regional lung perfusion in children from contrast enhanced 3D MRI

    Heimann, Tobias; Eichinger, Monika; Bauman, Grzegorz; Bischoff, Arved; Puderbach, Michael; Meinzer, Hans-Peter

    2012-03-01

    MRI perfusion images give information about regional lung function and can be used to detect pulmonary pathologies in cystic fibrosis (CF) children. However, manual assessment of the percentage of pathologic tissue in defined lung subvolumes features large inter- and intra-observer variation, making it difficult to determine disease progression consistently. We present an automated method to calculate a regional score for this purpose. First, lungs are located based on thresholding and morphological operations. Second, statistical shape models of left and right children's lungs are initialized at the determined locations and used to precisely segment morphological images. Segmentation results are transferred to perfusion maps and employed as masks to calculate perfusion statistics. An automated threshold to determine pathologic tissue is calculated and used to determine accurate regional scores. We evaluated the method on 10 MRI images and achieved an average surface distance of less than 1.5 mm compared to manual reference segmentations. Pathologic tissue was detected correctly in 9 cases. The approach seems suitable for detecting early signs of CF and monitoring response to therapy.

  1. 3D-TOF MRA与MRI联合应用在颅内动脉瘤的诊断价值%Evaluation of 3D-TOF MRA Combined with MRI in the Diagnosis of Intracranial Aneurysms

    沈文东; 曹志宏; 吴立伟; 单海荣

    2012-01-01

    Objective To assess the Evaluation of 3D-TOF MRA combined with MRI in the diagnosis of intracranial aneurysms. Methods 18 cases of intracranial aneurysms were confirmed by digital subtraction angiography(DSA),To retrospectively analyze the MRA and MRI information. MRA was done with 3D-TOF sequences and MRI was performed with SET1 and T2 weighted suquences. Results 21 aneurysms were proved by in 18 cases, 19 aneurysms were found on 3D-TOF MRA. 17 aneurysms were found on MRI. all aneurysms were found on 3D-TOF MRA combined with MRi. Conclusion 3D-TOF MRA combined with MRI may improve the diagnostic accuracy.%目的 探讨3D-TOF MRA与MRI联合应用在颅内动脉瘤中的诊断价值.方法 选择经DSA证实为颅内动脉瘤且资料齐全的18例患者,回顾性分析其MRA、MRI资料.MRA采用三维时间飞跃法(3D-TOF),MRI采用SE T1WI、T2WI成像.结果 18例患者共计21个病灶,3D-TOF MRA显示19个病灶,MRI显示17个病灶,3D-TOF MRA联合MRI则全部显示病灶并确诊.结论 3D-TOF MRA与MRI联合应用可极大地提高颅内动脉瘤的发现率及确诊率.

  2. 3D Medical Image Interpolation Based on Parametric Cubic Convolution

    2007-01-01

    In the process of display, manipulation and analysis of biomedical image data, they usually need to be converted to data of isotropic discretization through the process of interpolation, while the cubic convolution interpolation is widely used due to its good tradeoff between computational cost and accuracy. In this paper, we present a whole concept for the 3D medical image interpolation based on cubic convolution, and the six methods, with the different sharp control parameter, which are formulated in details. Furthermore, we also give an objective comparison for these methods using data sets with the different slice spacing. Each slice in these data sets is estimated by each interpolation method and compared with the original slice using three measures: mean-squared difference, number of sites of disagreement, and largest difference. According to the experimental results, we present a recommendation for 3D medical images under the different situations in the end.

  3. Technical illustration based on 3D CSG models

    GENG Wei-dong; DING Lei; YU Hong-feng; PAN Yun-he

    2005-01-01

    This paper presents an automatic non-photorealistic rendering approach to generating technical illustration from 3D models. It first decomposes the 3D object into a set of CSG primitives, and then performs the hidden surface removal based on the prioritized list, in which the rendition order of CSG primitives is sorted out by depth. Then, each primitive is illustrated by the pre-defined empirical lighting model, and the system mimics the stroke-drawing by user-specified style. In order to artistically and flexibly modulate the illumination, the empirical lighting model is defined by three major components: parameters of multi-level lighting intensities, parametric spatial occupations for each lighting level, and an interpolation method to calculate the lighting units into the spatial occupation of CSG primitives, instead of"pixel-by-pixel" painting. This region-by-region shading facilitates the simulation of illustration styles.

  4. Gesture Interaction Browser-Based 3D Molecular Viewer.

    Virag, Ioan; Stoicu-Tivadar, Lăcrămioara; Crişan-Vida, Mihaela

    2016-01-01

    The paper presents an open source system that allows the user to interact with a 3D molecular viewer using associated hand gestures for rotating, scaling and panning the rendered model. The novelty of this approach is that the entire application is browser-based and doesn't require installation of third party plug-ins or additional software components in order to visualize the supported chemical file formats. This kind of solution is suitable for instruction of users in less IT oriented environments, like medicine or chemistry. For rendering various molecular geometries our team used GLmol (a molecular viewer written in JavaScript). The interaction with the 3D models is made with Leap Motion controller that allows real-time tracking of the user's hand gestures. The first results confirmed that the resulting application leads to a better way of understanding various types of translational bioinformatics related problems in both biomedical research and education. PMID:27350455

  5. 3D Visual SLAM Based on Multiple Iterative Closest Point

    Chunguang Li

    2015-01-01

    Full Text Available With the development of novel RGB-D visual sensors, data association has been a basic problem in 3D Visual Simultaneous Localization and Mapping (VSLAM. To solve the problem, a VSLAM algorithm based on Multiple Iterative Closest Point (MICP is presented. By using both RGB and depth information obtained from RGB-D camera, 3D models of indoor environment can be reconstructed, which provide extensive knowledge for mobile robots to accomplish tasks such as VSLAM and Human-Robot Interaction. Due to the limited views of RGB-D camera, additional information about the camera pose is needed. In this paper, the motion of the RGB-D camera is estimated by a motion capture system after a calibration process. Based on the estimated pose, the MICP algorithm is used to improve the alignment. A Kinect mobile robot which is running Robot Operating System and the motion capture system has been used for experiments. Experiment results show that not only the proposed VSLAM algorithm achieved good accuracy and reliability, but also the 3D map can be generated in real time.

  6. 3D GIS spatial operation based on extended Euler operators

    Xu, Hongbo; Lu, Guonian; Sheng, Yehua; Zhou, Liangchen; Guo, Fei; Shang, Zuoyan; Wang, Jing

    2008-10-01

    The implementation of 3 dimensions spatial operations, based on certain data structure, has a lack of universality and is not able to treat with non-manifold cases, at present. ISO/DIS 19107 standard just presents the definition of Boolean operators and set operators for topological relationship query, and OGC GeoXACML gives formal definitions for several set functions without implementation detail. Aiming at these problems, based mathematical foundation on cell complex theory, supported by non-manifold data structure and using relevant research in the field of non-manifold geometry modeling for reference, firstly, this paper according to non-manifold Euler-Poincaré formula constructs 6 extended Euler operators and inverse operators to carry out creating, updating and deleting 3D spatial elements, as well as several pairs of supplementary Euler operators to convenient for implementing advanced functions. Secondly, we change topological element operation sequence of Boolean operation and set operation as well as set functions defined in GeoXACML into combination of extended Euler operators, which separates the upper functions and lower data structure. Lastly, we develop underground 3D GIS prototype system, in which practicability and credibility of extended Euler operators faced to 3D GIS presented by this paper are validated.

  7. Vision based error detection for 3D printing processes

    Baumann Felix

    2016-01-01

    Full Text Available 3D printers became more popular in the last decade, partly because of the expiration of key patents and the supply of affordable machines. The origin is located in rapid prototyping. With Additive Manufacturing (AM it is possible to create physical objects from 3D model data by layer wise addition of material. Besides professional use for prototyping and low volume manufacturing they are becoming widespread amongst end users starting with the so called Maker Movement. The most prevalent type of consumer grade 3D printers is Fused Deposition Modelling (FDM, also Fused Filament Fabrication FFF. This work focuses on FDM machinery because of their widespread occurrence and large number of open problems like precision and failure. These 3D printers can fail to print objects at a statistical rate depending on the manufacturer and model of the printer. Failures can occur due to misalignment of the print-bed, the print-head, slippage of the motors, warping of the printed material, lack of adhesion or other reasons. The goal of this research is to provide an environment in which these failures can be detected automatically. Direct supervision is inhibited by the recommended placement of FDM printers in separate rooms away from the user due to ventilation issues. The inability to oversee the printing process leads to late or omitted detection of failures. Rejects effect material waste and wasted time thus lowering the utilization of printing resources. Our approach consists of a camera based error detection mechanism that provides a web based interface for remote supervision and early failure detection. Early failure detection can lead to reduced time spent on broken prints, less material wasted and in some cases salvaged objects.

  8. Dixon imaging-based partial volume correction improves quantification of choline detected by breast 3D-MRSI

    Minarikova, Lenka; Gruber, Stephan; Bogner, Wolfgang; Trattnig, Siegfried; Chmelik, Marek [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, MR Center of Excellence, Vienna (Austria); Pinker-Domenig, Katja; Baltzer, Pascal A.T.; Helbich, Thomas H. [Medical University of Vienna, Department of Biomedical Imaging and Image-guided Therapy, Division of Molecular and Gender Imaging, Vienna (Austria)

    2014-09-14

    Our aim was to develop a partial volume (PV) correction method of choline (Cho) signals detected by breast 3D-magnetic resonance spectroscopic imaging (3D-MRSI), using information from water/fat-Dixon MRI. Following institutional review board approval, five breast cancer patients were measured at 3 T. 3D-MRSI (1 cm{sup 3} resolution, duration ∝11 min) and Dixon MRI (1 mm{sup 3}, ∝2 min) were measured in vivo and in phantoms. Glandular/lesion tissue was segmented from water/fat-Dixon MRI and transformed to match the resolution of 3D-MRSI. The resulting PV values were used to correct Cho signals. Our method was validated on a two-compartment phantom (choline/water and oil). PV values were correlated with the spectroscopic water signal. Cho signal variability, caused by partial-water/fat content, was tested in 3D-MRSI voxels located in/near malignant lesions. Phantom measurements showed good correlation (r = 0.99) with quantified 3D-MRSI water signals, and better homogeneity after correction. The dependence of the quantified Cho signal on the water/fat voxel composition was significantly (p < 0.05) reduced using Dixon MRI-based PV correction, compared to the original uncorrected data (1.60-fold to 3.12-fold) in patients. The proposed method allows quantification of the Cho signal in glandular/lesion tissue independent of water/fat composition in breast 3D-MRSI. This can improve the reproducibility of breast 3D-MRSI, particularly important for therapy monitoring. (orig.)

  9. Virtual reality 3D headset based on DMD light modulators

    Bernacki, Bruce E.; Evans, Allan; Tang, Edward

    2014-06-13

    We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micro-mirror devices (DMD). Our approach leverages silicon micro mirrors offering 720p resolution displays in a small form-factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high resolution and low power consumption. Applications include night driving, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design is described in which light from the DMD is imaged to infinity and the user’s own eye lens forms a real image on the user’s retina.

  10. Estimation of Pulmonary Motion in Healthy Subjects and Patients with Intrathoracic Tumors Using 3D-Dynamic MRI: Initial Results

    Plathow, Christian; Schoebinger, Max; Meinzer, Heinz Peter [German Cancer Research Center, Heidelberg (Germany); Herth, Felix; Tuengerthal, Siegfried [Clinic of Thoracic Disease, Heidelberg (Germany); Kauczor, Hans Ulrich [University of Heidelberg, Heidelberg (Germany)

    2009-12-15

    To estimate a new technique for quantifying regional lung motion using 3D-MRI in healthy volunteers and to apply the technique in patients with intra- or extrapulmonary tumors. Intraparenchymal lung motion during a whole breathing cycle was quantified in 30 healthy volunteers using 3D-dynamic MRI (FLASH [fast low angle shot] 3D, TRICKS [time-resolved interpolated contrast kinetics]). Qualitative and quantitative vector color maps and cumulative histograms were performed using an introduced semiautomatic algorithm. An analysis of lung motion was performed and correlated with an established 2D-MRI technique for verification. As a proof of concept, the technique was applied in five patients with non-small cell lung cancer (NSCLC) and 5 patients with malignant pleural mesothelioma (MPM). The correlation between intraparenchymal lung motion of the basal lung parts and the 2D-MRI technique was significant (r = 0.89, p < 0.05). Also, the vector color maps quantitatively illustrated regional lung motion in all healthy volunteers. No differences were observed between both hemithoraces, which was verified by cumulative histograms. The patients with NSCLC showed a local lack of lung motion in the area of the tumor. In the patients with MPM, there was global diminished motion of the tumor bearing hemithorax, which improved significantly after chemotherapy (CHT) (assessed by the 2D- and 3D-techniques) (p < 0.01). Using global spirometry, an improvement could also be shown (vital capacity 2.9 {+-} 0.5 versus 3.4 L {+-} 0.6, FEV1 0.9 {+-} 0.2 versus 1.4 {+-} 0.2 L) after CHT, but this improvement was not significant. A 3D-dynamic MRI is able to quantify intraparenchymal lung motion. Local and global parenchymal pathologies can be precisely located and might be a new tool used to quantify even slight changes in lung motion (e.g. in therapy monitoring, follow-up studies or even benign lung diseases)

  11. Estimation of Pulmonary Motion in Healthy Subjects and Patients with Intrathoracic Tumors Using 3D-Dynamic MRI: Initial Results

    To estimate a new technique for quantifying regional lung motion using 3D-MRI in healthy volunteers and to apply the technique in patients with intra- or extrapulmonary tumors. Intraparenchymal lung motion during a whole breathing cycle was quantified in 30 healthy volunteers using 3D-dynamic MRI (FLASH [fast low angle shot] 3D, TRICKS [time-resolved interpolated contrast kinetics]). Qualitative and quantitative vector color maps and cumulative histograms were performed using an introduced semiautomatic algorithm. An analysis of lung motion was performed and correlated with an established 2D-MRI technique for verification. As a proof of concept, the technique was applied in five patients with non-small cell lung cancer (NSCLC) and 5 patients with malignant pleural mesothelioma (MPM). The correlation between intraparenchymal lung motion of the basal lung parts and the 2D-MRI technique was significant (r = 0.89, p < 0.05). Also, the vector color maps quantitatively illustrated regional lung motion in all healthy volunteers. No differences were observed between both hemithoraces, which was verified by cumulative histograms. The patients with NSCLC showed a local lack of lung motion in the area of the tumor. In the patients with MPM, there was global diminished motion of the tumor bearing hemithorax, which improved significantly after chemotherapy (CHT) (assessed by the 2D- and 3D-techniques) (p < 0.01). Using global spirometry, an improvement could also be shown (vital capacity 2.9 ± 0.5 versus 3.4 L ± 0.6, FEV1 0.9 ± 0.2 versus 1.4 ± 0.2 L) after CHT, but this improvement was not significant. A 3D-dynamic MRI is able to quantify intraparenchymal lung motion. Local and global parenchymal pathologies can be precisely located and might be a new tool used to quantify even slight changes in lung motion (e.g. in therapy monitoring, follow-up studies or even benign lung diseases)

  12. Fast vision-based catheter 3D reconstruction

    Moradi Dalvand, Mohsen; Nahavandi, Saeid; Howe, Robert D.

    2016-07-01

    Continuum robots offer better maneuverability and inherent compliance and are well-suited for surgical applications as catheters, where gentle interaction with the environment is desired. However, sensing their shape and tip position is a challenge as traditional sensors can not be employed in the way they are in rigid robotic manipulators. In this paper, a high speed vision-based shape sensing algorithm for real-time 3D reconstruction of continuum robots based on the views of two arbitrary positioned cameras is presented. The algorithm is based on the closed-form analytical solution of the reconstruction of quadratic curves in 3D space from two arbitrary perspective projections. High-speed image processing algorithms are developed for the segmentation and feature extraction from the images. The proposed algorithms are experimentally validated for accuracy by measuring the tip position, length and bending and orientation angles for known circular and elliptical catheter shaped tubes. Sensitivity analysis is also carried out to evaluate the robustness of the algorithm. Experimental results demonstrate good accuracy (maximum errors of  ±0.6 mm and  ±0.5 deg), performance (200 Hz), and robustness (maximum absolute error of 1.74 mm, 3.64 deg for the added noises) of the proposed high speed algorithms.

  13. Several 3D graphics software study based on Linux

    This paper introduces the request of single event display in BES III online data acquisition system and presents OpenGL, ROOT, VRML, Java3D 3D graphics software. After making comparison with these software in effect and performance, finally we choose Java3D technology for developing single event display. (authors)

  14. Comparison of 3D and 2D FSE T2-weighted MRI in the diagnosis of deep pelvic endometriosis: Preliminary results

    Aim: To evaluate image quality and diagnostic accuracy of two- (2D) and three-dimensional (3D) T2-weighted magnetic resonance imaging (MRI) for the evaluation of deep infiltrating endometriosis (DIE). Materials and methods: One hundred and ten consecutive patients with suspicion of endometriosis were recruited at two institutions over a 5-month period. Twenty-three women underwent surgery, 18 had DIE at histology. Two readers independently evaluated 3D and 2D MRI for image quality and diagnosis of DIE. Descriptive analysis, chi-square test for categorical or nominal variables, McNemar test for comparison between 3D and 2D T2-weighted MRI, and weighted “statistics” for intra- and interobserver agreement were used for statistical analysis. Results: Both readers found that 3D yielded significantly lower image quality than 2D MRI (p < 0.0001). Acquisition time for 3D was significantly shorter than 2D MRI (p < 0.01). 3D offered similar accuracy to diagnose DIE compared to 2D MRI. For all locations of endometriosis, a high or variable intra-observer agreement was observed for reader 1 and 2, respectively. Conclusions: Despite a lower overall image quality, 3D provides significant time saving and similar accuracy than multiplanar 2D MRI in the diagnosis of specific DIE locations.

  15. Realistic terrain visualization based on 3D virtual world technology

    Huang, Fengru; Lin, Hui; Chen, Bin; Xiao, Cai

    2010-11-01

    The rapid advances in information technologies, e.g., network, graphics processing, and virtual world, have provided challenges and opportunities for new capabilities in information systems, Internet applications, and virtual geographic environments, especially geographic visualization and collaboration. In order to achieve meaningful geographic capabilities, we need to explore and understand how these technologies can be used to construct virtual geographic environments to help to engage geographic research. The generation of three-dimensional (3D) terrain plays an important part in geographical visualization, computer simulation, and virtual geographic environment applications. The paper introduces concepts and technologies of virtual worlds and virtual geographic environments, explores integration of realistic terrain and other geographic objects and phenomena of natural geographic environment based on SL/OpenSim virtual world technologies. Realistic 3D terrain visualization is a foundation of construction of a mirror world or a sand box model of the earth landscape and geographic environment. The capabilities of interaction and collaboration on geographic information are discussed as well. Further virtual geographic applications can be developed based on the foundation work of realistic terrain visualization in virtual environments.

  16. EEG-based usability assessment of 3D shutter glasses

    Wenzel, Markus A.; Schultze-Kraft, Rafael; Meinecke, Frank C.; Cardinaux, Fabien; Kemp, Thomas; Müller, Klaus-Robert; Curio, Gabriel; Blankertz, Benjamin

    2016-02-01

    Objective. Neurotechnology can contribute to the usability assessment of products by providing objective measures of neural workload and can uncover usability impediments that are not consciously perceived by test persons. In this study, the neural processing effort imposed on the viewer of 3D television by shutter glasses was quantified as a function of shutter frequency. In particular, we sought to determine the critical shutter frequency at which the ‘neural flicker’ vanishes, such that visual fatigue due to this additional neural effort can be prevented by increasing the frequency of the system. Approach. Twenty-three participants viewed an image through 3D shutter glasses, while multichannel electroencephalogram (EEG) was recorded. In total ten shutter frequencies were employed, selected individually for each participant to cover the range below, at and above the threshold of flicker perception. The source of the neural flicker correlate was extracted using independent component analysis and the flicker impact on the visual cortex was quantified by decoding the state of the shutter from the EEG. Main Result. Effects of the shutter glasses were traced in the EEG up to around 67 Hz—about 20 Hz over the flicker perception threshold—and vanished at the subsequent frequency level of 77 Hz. Significance. The impact of the shutter glasses on the visual cortex can be detected by neurotechnology even when a flicker is not reported by the participants. Potential impact. Increasing the shutter frequency from the usual 50 Hz or 60 Hz to 77 Hz reduces the risk of visual fatigue and thus improves shutter-glass-based 3D usability.

  17. 3D Printed Paper-Based Microfluidic Analytical Devices

    Yong He

    2016-06-01

    Full Text Available As a pump-free and lightweight analytical tool, paper-based microfluidic analytical devices (μPADs attract more and more interest. If the flow speed of μPAD can be programmed, the analytical sequences could be designed and they will be more popular. This reports presents a novel μPAD, driven by the capillary force of cellulose powder, printed by a desktop three-dimensional (3D printer, which has some promising features, such as easy fabrication and programmable flow speed. First, a suitable size-scale substrate with open microchannels on its surface is printed. Next, the surface of the substrate is covered with a thin layer of polydimethylsiloxane (PDMS to seal the micro gap caused by 3D printing. Then, the microchannels are filled with a mixture of cellulose powder and deionized water in an appropriate proportion. After drying in an oven at 60 °C for 30 min, it is ready for use. As the different channel depths can be easily printed, which can be used to achieve the programmable capillary flow speed of cellulose powder in the microchannels. A series of microfluidic analytical experiments, including quantitative analysis of nitrite ion and fabrication of T-sensor were used to demonstrate its capability. As the desktop 3D printer (D3DP is very cheap and accessible, this device can be rapidly printed at the test field with a low cost and has a promising potential in the point-of-care (POC system or as a lightweight platform for analytical chemistry.

  18. 3D morphology of the rear foot from MRI data: technical validation and clinical description

    Stindel, Eric; Udupa, Jayaram K.; Hirsch, Bruce E.; Odhner, Dewey; Couture, Christine

    1998-06-01

    The purpose of this work is to characterize the 3D morphology of the bones of the rear foot using MR data. This work has two subaims: (1) to study the variability of the various computed architectural measures as a result of the subjectivity and variations in the various processing operations; (2) to study the morphology of the bones included in the peritalar complex. Each image data set utilized in this study consists of 60 longitudinal slices of the foot acquired on a 1.5 T commercial GE MR system. Our description of the rear foot morphology is based mainly on the principal axes, which represent the inertia axes of the bones, as well as on the bone surfaces. We use the live-wire method for segmenting and forming the surfaces of the bones. In the first part of this work, we focus on the dependence of the principal axes system on segmentation and on scan orientation. In the second part, we describe the normal morphology of the rear foot considering the four bones (calcaneus, cuboid, navicular, talus) and compare them to a population from the Upper Pleistocene. We conclude that this non-invasive method can be used in live patients to characterize the bone morphology or as a comparative method to classify population of bones. in spite of the variations involved in the various processing operations.

  19. Multidimensional morphometric 3D MRI analyses for detecting brain abnormalities in children: impact of control population.

    Wilke, Marko; Rose, Douglas F; Holland, Scott K; Leach, James L

    2014-07-01

    Automated morphometric approaches are used to detect epileptogenic structural abnormalities in 3D MR images in adults, using the variance of a control population to obtain z-score maps in an individual patient. Due to the substantial changes the developing human brain undergoes, performing such analyses in children is challenging. This study investigated six features derived from high-resolution T1 datasets in four groups: normal children (1.5T or 3T data), normal clinical scans (3T data), and patients with structural brain lesions (3T data), with each n = 10. Normative control data were obtained from the NIH study on normal brain development (n = 401). We show that control group size substantially influences the captured variance, directly impacting the patient's z-scores. Interestingly, matching on gender does not seem to be beneficial, which was unexpected. Using data obtained at higher field scanners produces slightly different base rates of suprathreshold voxels, as does using clinically derived normal studies, suggesting a subtle but systematic effect of both factors. Two approaches for controlling suprathreshold voxels in a multidimensional approach (combining features and requiring a minimum cluster size) were shown to be substantial and effective in reducing this number. Finally, specific strengths and limitations of such an approach could be demonstrated in individual cases. PMID:25050423

  20. Method for 3D Rendering Based on Intersection Image Display Which Allows Representation of Internal Structure of 3D objects

    Kohei Arai

    2013-06-01

    Full Text Available Method for 3D rendering based on intersection image display which allows representation of internal structure is proposed. The proposed method is essentially different from the conventional volume rendering based on solid model which allows representation of just surface of the 3D objects. By using afterimage, internal structure can be displayed through exchanging the intersection images with internal structure for the proposed method. Through experiments with CT scan images, the proposed method is validated. Also one of other applicable areas of the proposed for design of 3D pattern of Large Scale Integrated Circuit: LSI is introduced. Layered patterns of LSI can be displayed and switched by using human eyes only. It is confirmed that the time required for displaying layer pattern and switching the pattern to the other layer by using human eyes only is much faster than that using hands and fingers.

  1. Ultra-realistic 3-D imaging based on colour holography

    Bjelkhagen, H. I.

    2013-02-01

    A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

  2. 3-D MRI for lumbar degenerative diseases; Visualization of nerve roots

    Aota, Yoichi; Kumano, Kiyoshi; Hirabayashi, Shigeru; Ogawa, Yu; Izumi, Yasujiro; Yoshikawa, Koki (Kanto Rosai Hospital, Kawasaki (Japan)); Yamazaki, Tatsuo

    1993-07-01

    Three-dimensional (3-D) magnetic resonance (MR) images obtained from 10 patients with lumbar degenerative diseases were retrospectively reviewed to determine how far 3-D MR imaging is capable of demonstrating nerve roots. In 8 of the 10 patients, the area up to the dorsal root ganglion was visualized on 3-D MR images. Thus, it is capable of detecting a wide area of nerve roots, thereby allowing the determination of running of nerve root, and size and location of dorsal root ganglion. In delineating the area from the dural canal to root cyst, 3-D MR imaging was equal to conventional myelography. The former was superior to the latter in detecting the positional relation between the degenerative intervertebral disc and the nerve root, and herniation-compressed root cyst. In 3 of 9 patients who presented with root symptoms, disturbed nerve roots were of high signal on 3-D MR images. This may suggest that it has the potential for selectively detecting root nerves associated with clinical manifestations. (N.K.).

  3. Improving 3D Wavelet-Based Compression of Hyperspectral Images

    Klimesh, Matthew; Kiely, Aaron; Xie, Hua; Aranki, Nazeeh

    2009-01-01

    Two methods of increasing the effectiveness of three-dimensional (3D) wavelet-based compression of hyperspectral images have been developed. (As used here, images signifies both images and digital data representing images.) The methods are oriented toward reducing or eliminating detrimental effects of a phenomenon, referred to as spectral ringing, that is described below. In 3D wavelet-based compression, an image is represented by a multiresolution wavelet decomposition consisting of several subbands obtained by applying wavelet transforms in the two spatial dimensions corresponding to the two spatial coordinate axes of the image plane, and by applying wavelet transforms in the spectral dimension. Spectral ringing is named after the more familiar spatial ringing (spurious spatial oscillations) that can be seen parallel to and near edges in ordinary images reconstructed from compressed data. These ringing phenomena are attributable to effects of quantization. In hyperspectral data, the individual spectral bands play the role of edges, causing spurious oscillations to occur in the spectral dimension. In the absence of such corrective measures as the present two methods, spectral ringing can manifest itself as systematic biases in some reconstructed spectral bands and can reduce the effectiveness of compression of spatially-low-pass subbands. One of the two methods is denoted mean subtraction. The basic idea of this method is to subtract mean values from spatial planes of spatially low-pass subbands prior to encoding, because (a) such spatial planes often have mean values that are far from zero and (b) zero-mean data are better suited for compression by methods that are effective for subbands of two-dimensional (2D) images. In this method, after the 3D wavelet decomposition is performed, mean values are computed for and subtracted from each spatial plane of each spatially-low-pass subband. The resulting data are converted to sign-magnitude form and compressed in a

  4. Lossless 3D Steganography Based on MST and Connectivity Modification

    Amat, Philippe; Puech, William; Druon, Sébastien; Pedeboy, Jean-Pierre

    2010-01-01

    International audience Data hiding has become increasingly important for many applications, like confidential transmission, video surveillance, military and medical applications. In this paper we present a new approach of 3D object data hiding without changing the position of vertices in the 3D space. The main idea of the proposed method is to find and to synchronize particular areas of the 3D objects used to embed the message. The embedding is carried out by changing the connectivity of e...

  5. 3D Healpix-based Skymaps Visualization using Java

    Joliet, E.; O'Mullane, W.; Górski, K. M.; Banday, A. J.; Hivon, E.; Carr, R.

    2008-08-01

    HEALPix {http://healpix.jpl.nasa.gov/} is useful for data analysis and visualization. Gaia is the ESA space astrometry cornerstone mission the main objective of wich is to astrometrically and spectro-photometrically map 10^{9} celestial objects (mostly in our galaxy) with unprecedented accuracy. The data will be organized and stored in a central database at ESAC (Spain). The data treatment needs data analysis and visualization tools to accomplish a successful mission. The 3D Healpix-based skymaps are used as part of the interactive diagnostic tools as well as within the core processing. We present the HEALPix Java library and give some examples of its use within Gaia and Planck processing.

  6. Decreased 3D observer variation with matched CT-MRI, for target delineation in nasopharynx cancer

    Rasch, C.R.; Steenbakkers, R.J.; Fitton, I.; Duppen, J.C.; Nowak, P.J.; Pameijer, F.A.; Eisbruch, A.; Kaanders, J.H.A.M.; Paulsen, F.; Herk, M. van

    2010-01-01

    PURPOSE: To determine the variation in target delineation of nasopharyngeal carcinoma and the impact of measures to minimize this variation. MATERIALS AND METHODS: For ten nasopharyngeal cancer patients, ten observers each delineated the Clinical Target Volume (CTV) and the CTV elective. After 3D an

  7. Influence of Maturation, Pathology and Functional Lateralization on 3D Sulcal Morphology using MRI

    Jensen, Betina Vase

    morphometry using Magnetic Resonance Imaging (MRI) and spatial statistical methods. The sulcal morphology has been studied with respect to: the normal development of a central sulcus; in relation to functional lateralization of the motor hand area in central sulcus and, finally, in relation to a pathological...

  8. Evaluation of grading of preoperative internal derangement of knee joint by MRI with 3D-COSMIC sequence

    Usefulness of 3D-coherent oscillatory state acquisition for the manipulation of image contrast (COSMIC) sequence is evaluated by comparison of grades of the MR image before surgery and of postoperative finding for the cartilage, ligament and meniscus. The sequence can give images with intensive signals of the joint parts essentially having low T2/T1 values. Subjects are 18 cases (8 M/10 F, average age of 41 y) with degenerated cartilage (15 knees), injured anterior cruciate ligament (9) and meniscus (16). MRI machine used is GE Signa HD x 1.5 T ver. 14 M 5, and coronary and sagittal sections of the knee are COSMIC acquisited with repetition time 8.3 msec, echo time 4.1 msec, bandwidth 50 kHz and slice thickness 2 mm. The cartilage degeneration is graded from Grade 0 to 4 along with Outerbridge's classification by postoperative findings and with 5 defined grades of preoperative morphological MRI findings. Ligament injury is definitively graded in Grade 0-2 with post-/pre-operative findings. Meniscal injury is graded in 0-3 with defined postoperative findings and with modified Mink's classification of preoperative MRI findings. All images are assessed by 3 radiological doctors. Sensitivity, specificity and diagnostic accuracy are evaluated for each joint part above: the accuracies in grading (0-4/3) and region for the cartilage are respectively 69.4-100% and 61.1-83.3%; for ligament, 88.9-83.3% and 88.9%; and for meniscus, 69.4-61.1% and 61.1-77.8%. Grading of the preoperative MRI with 3D-COSMIC sequence is thus shown useful for diagnosing the degree and region of knee derangement. (T.T.)

  9. Hydrogel-based reinforcement of 3D bioprinted constructs.

    Melchels, Ferry P W; Blokzijl, Maarten M; Levato, Riccardo; Peiffer, Quentin C; Ruijter, Mylène de; Hennink, Wim E; Vermonden, Tina; Malda, Jos

    2016-01-01

    Progress within the field of biofabrication is hindered by a lack of suitable hydrogel formulations. Here, we present a novel approach based on a hybrid printing technique to create cellularized 3D printed constructs. The hybrid bioprinting strategy combines a reinforcing gel for mechanical support with a bioink to provide a cytocompatible environment. In comparison with thermoplastics such as [Formula: see text]-polycaprolactone, the hydrogel-based reinforcing gel platform enables printing at cell-friendly temperatures, targets the bioprinting of softer tissues and allows for improved control over degradation kinetics. We prepared amphiphilic macromonomers based on poloxamer that form hydrolysable, covalently cross-linked polymer networks. Dissolved at a concentration of 28.6%w/w in water, it functions as reinforcing gel, while a 5%w/w gelatin-methacryloyl based gel is utilized as bioink. This strategy allows for the creation of complex structures, where the bioink provides a cytocompatible environment for encapsulated cells. Cell viability of equine chondrocytes encapsulated within printed constructs remained largely unaffected by the printing process. The versatility of the system is further demonstrated by the ability to tune the stiffness of printed constructs between 138 and 263 kPa, as well as to tailor the degradation kinetics of the reinforcing gel from several weeks up to more than a year. PMID:27431861

  10. 3D texture analysis reveals imperceptible MRI textural alterations in the thalamus and putamen in progressive myoclonic epilepsy type 1, EPM1.

    Sanna Suoranta

    Full Text Available Progressive myoclonic epilepsy type 1 (EPM1 is an autosomal recessively inherited neurodegenerative disorder characterized by young onset age, myoclonus and tonic-clonic epileptic seizures. At the time of diagnosis, the visual assessment of the brain MRI is usually normal, with no major changes found later. Therefore, we utilized texture analysis (TA to characterize and classify the underlying properties of the affected brain tissue by means of 3D texture features. Sixteen genetically verified patients with EPM1 and 16 healthy controls were included in the study. TA was performed upon 3D volumes of interest that were placed bilaterally in the thalamus, amygdala, hippocampus, caudate nucleus and putamen. Compared to the healthy controls, EPM1 patients had significant textural differences especially in the thalamus and right putamen. The most significantly differing texture features included parameters that measure the complexity and heterogeneity of the tissue, such as the co-occurrence matrix-based entropy and angular second moment, and also the run-length matrix-based parameters of gray-level non-uniformity, short run emphasis and long run emphasis. This study demonstrates the usability of 3D TA for extracting additional information from MR images. Textural alterations which suggest complex, coarse and heterogeneous appearance were found bilaterally in the thalamus, supporting the previous literature on thalamic pathology in EPM1. The observed putamenal involvement is a novel finding. Our results encourage further studies on the clinical applications, feasibility, reproducibility and reliability of 3D TA.

  11. Energy harvesting “3-D knitted spacer” based piezoelectric textiles

    Anand, S.; Soin, N.; Shah, T. H.; Siores, E.

    2016-07-01

    The piezoelectric effect in Poly(vinylidene fluoride), PVDF, was discovered over four decades ago and since then, significant work has been carried out aiming at the production of high p-phase fibres and their integration into fabric structures for energy harvesting. However, little work has been done in the area of production of “true piezoelectric fabric structures” based on flexible polymeric materials such as PVDF. In this work, we demonstrate “3-D knitted spacer” technology based all-fibre piezoelectric fabrics as power generators and energy harvesters. The knitted single-structure piezoelectric generator consists of high p-phase (~80%) piezoelectric PVDF monofilaments as the spacer yarn interconnected between silver (Ag) coated polyamide multifilament yarn layers acting as the top and bottom electrodes. The novel and unique textile structure provides an output power density in the range of 1.105.10 gWcm-2 at applied impact pressures in the range of 0.02-0.10 MPa, thus providing significantly higher power outputs and efficiencies over the existing 2-D woven and nonwoven piezoelectric structures. The high energy efficiency, mechanical durability and comfort of the soft, flexible and all-fibre based power generator is highly attractive for a variety of potential applications such as wearable electronic systems and energy harvesters charged from ambient environment or by human movement.

  12. 3D+t brain MRI segmentation using robust 4D Hidden Markov Chain.

    Lavigne, François; Collet, Christophe; Armspach, Jean-Paul

    2014-01-01

    In recent years many automatic methods have been developed to help physicians diagnose brain disorders, but the problem remains complex. In this paper we propose a method to segment brain structures on two 3D multi-modal MR images taken at different times (longitudinal acquisition). A bias field correction is performed with an adaptation of the Hidden Markov Chain (HMC) allowing us to take into account the temporal correlation in addition to spatial neighbourhood information. To improve the robustness of the segmentation of the principal brain structures and to detect Multiple Sclerosis Lesions as outliers the Trimmed Likelihood Estimator (TLE) is used during the process. The method is validated on 3D+t brain MR images. PMID:25571045

  13. Epileptogenic lesion quantification in MRI using contralateral 3D texture comparisons

    Jiménez del Toro, Oscar Alfonso; Foncubierta-Rodríguez, Antonio; Vargas Gomez, Maria-Isabel; Müller, Henning; Depeursinge, Adrien

    2014-01-01

    Epilepsy is a disorder of the brain that can lead to acute crisis and if possible an intervention can help patients. The exact localization of epileptogenic lesions influences the outcome of epilepsy surgery. Magnetic resonance (MR) imaging is clinically used for lesion detection and treatment planning, mainly through simple visual analysis. However, visual inspection in MR imaging can be highly subjective and subtle 3D structural abnormalities can be missclassified or not resected completely...

  14. MRI ANALYSIS OF 3D NORMAL AND POST-GLOSSECTOMY TONGUE MOTION IN SPEECH

    Xing, Fangxu; Murano, Emi Z.; Lee, Junghoon; Woo, Jonghye; Stone, Maureen; Prince, Jerry L.

    2013-01-01

    Measuring the internal muscular motion and deformation of the tongue during natural human speech is of high interest to head and neck surgeons and speech language pathologists. A pipeline for calculating 3D tongue motion from dynamic cine and tagged Magnetic Resonance (MR) images during speech has been developed. This paper presents the result of a complete analysis of eleven subjects’ (seven normal controls and four glossectomy patients) global tongue motion during speech obtained through MR...

  15. Fully Automatic 3D Glioma Extraction in Multi-contrast MRI

    Dvořák, Pavel; Bartušek, Karel

    Berlin: Springer, 2014, s. 239-246. ISBN 978-3-319-11755-3. [International Conference on Image Analysis and Recognition /11./ (ICAR 2014). Vilamoura (PT), 22.10.2014-24.10.2014] R&D Projects: GA ČR GAP102/12/1104; GA MŠk(CZ) LD14069 Institutional support: RVO:68081731 Keywords : brain tumor * image segmentation * MRI * multi-resolution analysis * symmetry analysis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  16. 3D Model Retrieval Based on Semantic and Shape Indexes

    Kassimi, My Abdellah

    2011-01-01

    The size of 3D models used on the web or stored in databases is becoming increasingly high. Then, an efficient method that allows users to find similar 3D objects for a given 3D model query has become necessary. Keywords and the geometry of a 3D model cannot meet the needs of users' retrieval because they do not include the semantic information. In this paper, a new method has been proposed to 3D models retrieval using semantic concepts combined with shape indexes. To obtain these concepts, we use the machine learning methods to label 3D models by k-means algorithm in measures and shape indexes space. Moreover, semantic concepts have been organized and represented by ontology language OWL and spatial relationships are used to disambiguate among models of similar appearance. The SPARQL query language has been used to question the information displayed in this language and to compute the similarity between two 3D models. We interpret our results using the Princeton Shape Benchmark Database and the results show ...

  17. 3D reconstruction based on spatial vanishing information

    Yuan Shu; Zheng Tan

    2005-01-01

    An approach for the three-dimensional (3D) reconstruction of architectural scenes from two un-calibrated images is described in this paper. From two views of one architectural structure, three pairs of corresponding vanishing points of three major mutual orthogonal directions can be extracted. The simple but powerful constraints of parallelism and orthogonal lines in architectural scenes can be used to calibrate the cameras and to recover the 3D information of the structure. This approach is applied to the real images of architectural scenes, and a 3D model of a building in virtual reality modelling language (VRML) format is presented which illustrates the method with successful performance.

  18. Virtual reality 3D headset based on DMD light modulators

    Bernacki, Bruce E.; Evans, Allan; Tang, Edward

    2014-06-01

    We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micromirror devices (DMD). Current methods for presenting information for virtual reality are focused on either polarizationbased modulators such as liquid crystal on silicon (LCoS) devices, or miniature LCD or LED displays often using lenses to place the image at infinity. LCoS modulators are an area of active research and development, and reduce the amount of viewing light by 50% due to the use of polarization. Viewable LCD or LED screens may suffer low resolution, cause eye fatigue, and exhibit a "screen door" or pixelation effect due to the low pixel fill factor. Our approach leverages a mature technology based on silicon micro mirrors delivering 720p resolution displays in a small form-factor with high fill factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high-definition resolution and low power consumption, and many of the design methods developed for DMD projector applications can be adapted to display use. Potential applications include night driving with natural depth perception, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design concept is described in which light from the DMD is imaged to infinity and the user's own eye lens forms a real image on the user's retina resulting in a virtual retinal display.

  19. PACS-based interface for 3D anatomical structure visualization and surgical planning

    Koehl, Christophe; Soler, Luc; Marescaux, Jacques

    2002-05-01

    The interpretation of radiological image is routine but it remains a rather difficult task for physicians. It requires complex mental processes, that permit translation from 2D slices into 3D localization and volume determination of visible diseases. An easier and more extensive visualization and exploitation of medical images can be reached through the use of computer-based systems that provide real help from patient admission to post-operative followup. In this way, we have developed a 3D visualization interface linked to a PACS database that allows manipulation and interaction on virtual organs delineated from CT-scan or MRI. This software provides the 3D real-time surface rendering of anatomical structures, an accurate evaluation of volumes and distances and the improvement of radiological image analysis and exam annotation through a negatoscope tool. It also provides a tool for surgical planning allowing the positioning of an interactive laparoscopic instrument and the organ resection. The software system could revolutionize the field of computerized imaging technology. Indeed, it provides a handy and portable tool for pre-operative and intra-operative analysis of anatomy and pathology in various medical fields. This constitutes the first step of the future development of augmented reality and surgical simulation systems.

  20. Location based augmented reality application on Unity 3D

    Serra Font, Antoni

    2013-01-01

    This document presents the development and steps taken in order to create an augmented reality application using the Unity 3D software using a mobile handheld device. The steps of the development will be explained and the performance evaluated.

  1. Symmetry-Based Conflict Detection and Resolution Method towards Web3D-based Collaborative Design

    Mingjiu Yu; Hongming Cai; Xiaoming Ma; Lihong Jiang

    2016-01-01

    In the process of web3D-based collaborative design, it is necessary to completely prevent operation conflicts among designers due to distributed environments and complex 3D models. Therefore, conflict detection and conflict resolution are of great significance to attain an acceptable result. In order to facilitate effective and smooth design work, a symmetry-based collaborative design framework is proposed using the X3D operation models. Combined considerations cover both models and operation...

  2. Vision based error detection for 3D printing processes

    Baumann Felix; Roller Dieter

    2016-01-01

    3D printers became more popular in the last decade, partly because of the expiration of key patents and the supply of affordable machines. The origin is located in rapid prototyping. With Additive Manufacturing (AM) it is possible to create physical objects from 3D model data by layer wise addition of material. Besides professional use for prototyping and low volume manufacturing they are becoming widespread amongst end users starting with the so called Maker Movement. The most prevalent type...

  3. Gis-Based Smart Cartography Using 3d Modeling

    Malinverni, E. S.; Tassetti, A. N.

    2013-08-01

    3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.

  4. Creation of 3D digital anthropomorphic phantoms which model actual patient non-rigid body motion as determined from MRI and position tracking studies of volunteers

    Connolly, C. M.; Konik, A.; Dasari, P. K. R.; Segars, P.; Zheng, S.; Johnson, K. L.; Dey, J.; King, M. A.

    2011-03-01

    Patient motion can cause artifacts, which can lead to difficulty in interpretation. The purpose of this study is to create 3D digital anthropomorphic phantoms which model the location of the structures of the chest and upper abdomen of human volunteers undergoing a series of clinically relevant motions. The 3D anatomy is modeled using the XCAT phantom and based on MRI studies. The NURBS surfaces of the XCAT are interactively adapted to fit the MRI studies. A detailed XCAT phantom is first developed from an EKG triggered Navigator acquisition composed of sagittal slices with a 3 x 3 x 3 mm voxel dimension. Rigid body motion states are then acquired at breath-hold as sagittal slices partially covering the thorax, centered on the heart, with 9 mm gaps between them. For non-rigid body motion requiring greater sampling, modified Navigator sequences covering the entire thorax with 3 mm gaps between slices are obtained. The structures of the initial XCAT are then adapted to fit these different motion states. Simultaneous to MRI imaging the positions of multiple reflective markers on stretchy bands about the volunteer's chest and abdomen are optically tracked in 3D via stereo imaging. These phantoms with combined position tracking will be used to investigate both imaging-data-driven and motion-tracking strategies to estimate and correct for patient motion. Our initial application will be to cardiacperfusion SPECT imaging where the XCAT phantoms will be used to create patient activity and attenuation distributions for each volunteer with corresponding motion tracking data from the markers on the body-surface. Monte Carlo methods will then be used to simulate SPECT acquisitions, which will be used to evaluate various motion estimation and correction strategies.

  5. Math world: A game-based 3D Virtual Learning Environment (3D VLE) for second graders

    Jean Maitem; Rosmina Joy Cabauatan; Lorena Rabago; Bartolome Tanguilig III

    2012-01-01

    This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educatio...

  6. Math World: A Game-Based 3D Virtual Learning Environment (3D VLE) for Second Graders

    Jean Maitem; Rosmina Joy Cabauatan; Lorena Rabago

    2012-01-01

    This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World...

  7. 3D source localization of interictal spikes in epilepsy patients with MRI lesions

    Ding, Lei; Worrell, Gregory A.; Lagerlund, Terrence D.; He, Bin

    2006-08-01

    The present study aims to accurately localize epileptogenic regions which are responsible for epileptic activities in epilepsy patients by means of a new subspace source localization approach, i.e. first principle vectors (FINE), using scalp EEG recordings. Computer simulations were first performed to assess source localization accuracy of FINE in the clinical electrode set-up. The source localization results from FINE were compared with the results from a classic subspace source localization approach, i.e. MUSIC, and their differences were tested statistically using the paired t-test. Other factors influencing the source localization accuracy were assessed statistically by ANOVA. The interictal epileptiform spike data from three adult epilepsy patients with medically intractable partial epilepsy and well-defined symptomatic MRI lesions were then studied using both FINE and MUSIC. The comparison between the electrical sources estimated by the subspace source localization approaches and MRI lesions was made through the coregistration between the EEG recordings and MRI scans. The accuracy of estimations made by FINE and MUSIC was also evaluated and compared by R2 statistic, which was used to indicate the goodness-of-fit of the estimated sources to the scalp EEG recordings. The three-concentric-spheres head volume conductor model was built for each patient with three spheres of different radii which takes the individual head size and skull thickness into consideration. The results from computer simulations indicate that the improvement of source spatial resolvability and localization accuracy of FINE as compared with MUSIC is significant when simulated sources are closely spaced, deep, or signal-to-noise ratio is low in a clinical electrode set-up. The interictal electrical generators estimated by FINE and MUSIC are in concordance with the patients' structural abnormality, i.e. MRI lesions, in all three patients. The higher R2 values achieved by FINE than MUSIC

  8. 3D source localization of interictal spikes in epilepsy patients with MRI lesions

    The present study aims to accurately localize epileptogenic regions which are responsible for epileptic activities in epilepsy patients by means of a new subspace source localization approach, i.e. first principle vectors (FINE), using scalp EEG recordings. Computer simulations were first performed to assess source localization accuracy of FINE in the clinical electrode set-up. The source localization results from FINE were compared with the results from a classic subspace source localization approach, i.e. MUSIC, and their differences were tested statistically using the paired t-test. Other factors influencing the source localization accuracy were assessed statistically by ANOVA. The interictal epileptiform spike data from three adult epilepsy patients with medically intractable partial epilepsy and well-defined symptomatic MRI lesions were then studied using both FINE and MUSIC. The comparison between the electrical sources estimated by the subspace source localization approaches and MRI lesions was made through the coregistration between the EEG recordings and MRI scans. The accuracy of estimations made by FINE and MUSIC was also evaluated and compared by R2 statistic, which was used to indicate the goodness-of-fit of the estimated sources to the scalp EEG recordings. The three-concentric-spheres head volume conductor model was built for each patient with three spheres of different radii which takes the individual head size and skull thickness into consideration. The results from computer simulations indicate that the improvement of source spatial resolvability and localization accuracy of FINE as compared with MUSIC is significant when simulated sources are closely spaced, deep, or signal-to-noise ratio is low in a clinical electrode set-up. The interictal electrical generators estimated by FINE and MUSIC are in concordance with the patients' structural abnormality, i.e. MRI lesions, in all three patients. The higher R2 values achieved by FINE than MUSIC

  9. Qualitative and quantitative assessment of wrist MRI at 3.0T - Comparison between isotropic 3D turbo spin echo and isotropic 3D fast field echo and 2D turbo spin echo

    Jung, Jee Young [Dept. of Radiology, Chungang Univ. Hospital, School of Medicine, Chungang Univ. (Korea, Republic of); Yoon, Young Cheol [Dept. of Radiology, Samsung Medical Center, School of Medicine, Sungkyunkwan Univ. (Korea, Republic of)], e-mail: ycyoon@skku.edu; Jung, Jin Young [Dept. of Radiology, Saint Paul' s Hospital, The Catholic Univ. (Korea, Republic of); Choe, Bong-Keun [Dept. of Preventive Medicine, School of Medicine, Kyung Hee Univ., Seoul (Korea, Republic of)

    2013-04-15

    Background: Isotropic three-dimensional (3D) magnetic resonance imaging (MRI) has been applied to various joints. However, comparison for image quality between isotropic 3D MRI and two-dimensional (2D) turbo spin echo (TSE) sequence of the wrist at a 3T MR system has not been investigated. Purpose: To compare the image quality of isotropic 3D MRI including TSE intermediate-weighted (VISTA) sequence and fast field echo (FFE) sequence with 2D TSE intermediate-weighted sequence of the wrist joint at 3.0 T. Material and Methods: MRI was performed in 10 wrists of 10 healthy volunteers with isotropic 3D sequences (VISTA and FFE) and 2D TSE intermediate-weighted sequences at 3.0 T. The signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Contrast ratios (CRs) were calculated between fluid and cartilage, triangular fibrocartilage complex (TFCC), and the scapholunate ligament. Two radiologists independently assessed the visibility of TFCC, carpal ligaments, cartilage, tendons and nerves with a four-point grading scale. Statistical analysis to compare CRs (one way ANOVA with a Tukey test) and grades of visibility (Kruskal-Wallis test) between three sequences and those for inter-observer agreement (kappa analysis) were performed. Results: The SNR of 2D TSE (46.26) was higher than those of VISTA (23.34) and 3D FFE (19.41). CRs were superior in 2D TSE than VISTA (P = 0.02) for fluid-cartilage and in 2D TSE than 3D FFE (P < 0.01) for fluid-TFCC. The visibility was best in 2D TSE (P < 0.01) for TFCC and in VISTA (P = 0.01) for scapholunate ligament. The visibility was better in 2D TSE and 3D FFE (P 0.04) for cartilage and in VISTA than 3D FFE (P < 0.01) for TFCC. The inter-observer agreement for the visibility of anatomic structures was moderate or substantial. Conclusion: Image quality of 2D TSE was superior to isotropic 3D MR imaging for cartilage, and TFCC. 3D FFE has better visibility for cartilage than VISTA and VISTA has superior visibility for

  10. Prospective comparison of T2w-MRI and dynamic-contrast-enhanced MRI, 3D-MR spectroscopic imaging or diffusion-weighted MRI in repeat TRUS-guided biopsies

    Portalez, Daniel [Clinique Pasteur, 45, Department of Radiology, Toulouse (France); Rollin, Gautier; Mouly, Patrick; Jonca, Frederic; Malavaud, Bernard [Hopital de Rangueil, Department of Urology, Toulouse Cedex 9 (France); Leandri, Pierre [Clinique Saint Jean, 20, Department of Urology, Toulouse (France); Elman, Benjamin [Clinique Pasteur, 45, Department of Urology, Toulouse (France)

    2010-12-15

    To compare T2-weighted MRI and functional MRI techniques in guiding repeat prostate biopsies. Sixty-eight patients with a history of negative biopsies, negative digital rectal examination and elevated PSA were imaged before repeat biopsies. Dichotomous criteria were used with visual validation of T2-weighted MRI, dynamic contrast-enhanced MRI and literature-derived cut-offs for 3D-spectroscopy MRI (choline-creatine-to-citrate ratio >0.86) and diffusion-weighted imaging (ADC x 10{sup 3} mm{sup 2}/s < 1.24). For each segment and MRI technique, results were rendered as being suspicious/non-suspicious for malignancy. Sextant biopsies, transition zone biopsies and at least two additional biopsies of suspicious areas were taken. In the peripheral zones, 105/408 segments and in the transition zones 19/136 segments were suspicious according to at least one MRI technique. A total of 28/68 (41.2%) patients were found to have cancer. Diffusion-weighted imaging exhibited the highest positive predictive value (0.52) compared with T2-weighted MRI (0.29), dynamic contrast-enhanced MRI (0.33) and 3D-spectroscopy MRI (0.25). Logistic regression showed the probability of cancer in a segment increasing 12-fold when T2-weighted and diffusion-weighted imaging MRI were both suspicious (63.4%) compared with both being non-suspicious (5.2%). The proposed system of analysis and reporting could prove clinically relevant in the decision whether to repeat targeted biopsies. (orig.)

  11. Prospective comparison of T2w-MRI and dynamic-contrast-enhanced MRI, 3D-MR spectroscopic imaging or diffusion-weighted MRI in repeat TRUS-guided biopsies

    To compare T2-weighted MRI and functional MRI techniques in guiding repeat prostate biopsies. Sixty-eight patients with a history of negative biopsies, negative digital rectal examination and elevated PSA were imaged before repeat biopsies. Dichotomous criteria were used with visual validation of T2-weighted MRI, dynamic contrast-enhanced MRI and literature-derived cut-offs for 3D-spectroscopy MRI (choline-creatine-to-citrate ratio >0.86) and diffusion-weighted imaging (ADC x 103 mm2/s < 1.24). For each segment and MRI technique, results were rendered as being suspicious/non-suspicious for malignancy. Sextant biopsies, transition zone biopsies and at least two additional biopsies of suspicious areas were taken. In the peripheral zones, 105/408 segments and in the transition zones 19/136 segments were suspicious according to at least one MRI technique. A total of 28/68 (41.2%) patients were found to have cancer. Diffusion-weighted imaging exhibited the highest positive predictive value (0.52) compared with T2-weighted MRI (0.29), dynamic contrast-enhanced MRI (0.33) and 3D-spectroscopy MRI (0.25). Logistic regression showed the probability of cancer in a segment increasing 12-fold when T2-weighted and diffusion-weighted imaging MRI were both suspicious (63.4%) compared with both being non-suspicious (5.2%). The proposed system of analysis and reporting could prove clinically relevant in the decision whether to repeat targeted biopsies. (orig.)

  12. Collaboration on Scene Graph Based 3D Data

    Ammon, Lorenz; Bieri, Hanspeter

    Professional 3D digital content creation tools, like Alias Maya or discreet 3ds max, offer only limited support for a team of artists to work on a 3D model collaboratively. We present a scene graph repository system that enables fine-grained collaboration on scenes built using standard 3D DCC tools by applying the concept of collaborative versions to a general attributed scene graph. Artists can work on the same scene in parallel without locking out each other. The artists' changes to a scene are regularly merged to ensure that all artists can see each others progress and collaborate on current data. We introduce the concept of indirect changes and indirect conflicts to systematically inspect the effects that collaborative changes have on a scene. Inspecting indirect conflicts helps maintaining scene consistency by systematically looking for inconsistencies at the right places.

  13. Toward a Network Based 3D Printing Service

    Ndikuriyo, Laurier; Abdulla, Mohammad

    2013-01-01

    This bachelor’s thesis has given us an opportunity to gain insight into how to create a service from scratch and to develop it into a fully functional service. The 3D printer service starts when a customer uploads a file containing the 3D design that they want to have made via a website. The file is stored and the printing request is placed into a queue. After that the client simply waits until the object is printed, with all of the various steps being handled automatically. The uploaded file...

  14. Microseismic network design assessment based on 3D ray tracing

    Näsholm, Sven Peter; Wuestefeld, Andreas; Lubrano-Lavadera, Paul; Lang, Dominik; Kaschwich, Tina; Oye, Volker

    2016-04-01

    There is increasing demand on the versatility of microseismic monitoring networks. In early projects, being able to locate any triggers was considered a success. These early successes led to a better understanding of how to extract value from microseismic results. Today operators, regulators, and service providers work closely together in order to find the optimum network design to meet various requirements. In the current study we demonstrate an integrated and streamlined network capability assessment approach. It is intended for use during the microseismic network design process prior to installation. The assessments are derived from 3D ray tracing between a grid of event points and the sensors. Three aspects are discussed: 1) Magnitude of completeness or detection limit; 2) Event location accuracy; and 3) Ground-motion hazard. The network capability parameters 1) and 2) are estimated at all hypothetic event locations and are presented in the form of maps given a seismic sensor coordinate scenario. In addition, the ray tracing traveltimes permit to estimate the point-spread-functions (PSFs) at the event grid points. PSFs are useful in assessing the resolution and focusing capability of the network for stacking-based event location and imaging methods. We estimate the performance for a hypothetical network case with 11 sensors. We consider the well-documented region around the San Andreas Fault Observatory at Depth (SAFOD) located north of Parkfield, California. The ray tracing is done through a detailed velocity model which covers a 26.2 by 21.2 km wide area around the SAFOD drill site with a resolution of 200 m both for the P-and S-wave velocities. Systematic network capability assessment for different sensor site scenarios prior to installation facilitates finding a final design which meets the survey objectives.

  15. Mapping motion from 4D-MRI to 3D-CT for use in 4D dose calculations: A technical feasibility study

    Purpose: Target sites affected by organ motion require a time resolved (4D) dose calculation. Typical 4D dose calculations use 4D-CT as a basis. Unfortunately, 4D-CT images have the disadvantage of being a “snap-shot” of the motion during acquisition and of assuming regularity of breathing. In addition, 4D-CT acquisitions involve a substantial additional dose burden to the patient making many, repeated 4D-CT acquisitions undesirable. Here the authors test the feasibility of an alternative approach to generate patient specific 4D-CT data sets. Methods: In this approach motion information is extracted from 4D-MRI. Simulated 4D-CT data sets [which the authors call 4D-CT(MRI)] are created by warping extracted deformation fields to a static 3D-CT data set. The employment of 4D-MRI sequences for this has the advantage that no assumptions on breathing regularity are made, irregularities in breathing can be studied and, if necessary, many repeat imaging studies (and consequently simulated 4D-CT data sets) can be performed on patients and/or volunteers. The accuracy of 4D-CT(MRI)s has been validated by 4D proton dose calculations. Our 4D dose algorithm takes into account displacements as well as deformations on the originating 4D-CT/4D-CT(MRI) by calculating the dose of each pencil beam based on an individual time stamp of when that pencil beam is applied. According to corresponding displacement and density-variation-maps the position and the water equivalent range of the dose grid points is adjusted at each time instance. Results: 4D dose distributions, using 4D-CT(MRI) data sets as input were compared to results based on a reference conventional 4D-CT data set capturing similar motion characteristics. Almost identical 4D dose distributions could be achieved, even though scanned proton beams are very sensitive to small differences in the patient geometry. In addition, 4D dose calculations have been performed on the same patient, but using 4D-CT(MRI) data sets based on

  16. Role of combined DWIBS/3D-CE-T1w whole-body MRI in tumor staging: Comparison with PET-CT

    Objectives: To assess the diagnostic performance of whole-body magnetic resonance imaging (WB-MRI) by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) in malignant tumor detection and the potential diagnostic advantages in generating fused DWIBS/3D-contrast enhanced T1w (3D-CE-T1w) images. Methods: 45 cancer patients underwent 18F-FDG PET-CT and WB-MRI for staging purpose. Fused DWIBS/3D-CE T1w images were generated off-line. 3D-CE-T1w, DWIBS images alone and fused with 3D-CE T1w were compared by two readers groups for detection of primary diseases and local/distant metastases. Diagnostic performance between the three WB-MRI data sets was assessed using receiver operating characteristic (ROC) curve analysis. Imaging exams and histopathological results were used as standard of references. Results: Areas under the ROC curves of DWIBS vs. 3D-CE-T1w vs. both sequences in fused fashion were 0.97, 0.978, and 1.00, respectively. The diagnostic performance in tumor detection of fused DWIBS/3D-CE-T1w images were statistically superior to DWIBS (p < 0.001) and 3D-CE-T1w (p ≤ 0.002); while the difference between DWIBS and 3D-CE-T1w did not show statistical significance difference. Detection rates of malignancy did not differ between WB-MRI with DWIBS and 18F-FDG PET-CT. Conclusion: WB-MRI with DWIBS is to be considered as alternative tool to conventional whole-body methods for tumor staging and during follow-up in cancer patients.

  17. Role of combined DWIBS/3D-CE-T1w whole-body MRI in tumor staging: Comparison with PET-CT

    Manenti, Guglielmo, E-mail: guggi@tiscali.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Ciccio, Carmelo, E-mail: carmeciccio@libero.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Squillaci, Ettore, E-mail: ettoresquillaci@tiscali.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Strigari, Lidia, E-mail: strigari@ifo.it [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Via Elio Chianesi 53, 00144 Rome (Italy); Calabria, Ferdinando, E-mail: ferdinandocalabria@hotmail.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); Danieli, Roberta, E-mail: roberta.danieli@ptvonline.it [Department of Diagnostic and Molecular Imaging, Interventional Radiology and Radiotherapy, University ' Tor Vergata' , PTV Foundation - Policlinic ' Tor Vergata' , Viale Oxford 81, 00133 Rome (Italy); and others

    2012-08-15

    Objectives: To assess the diagnostic performance of whole-body magnetic resonance imaging (WB-MRI) by diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) in malignant tumor detection and the potential diagnostic advantages in generating fused DWIBS/3D-contrast enhanced T1w (3D-CE-T1w) images. Methods: 45 cancer patients underwent 18F-FDG PET-CT and WB-MRI for staging purpose. Fused DWIBS/3D-CE T1w images were generated off-line. 3D-CE-T1w, DWIBS images alone and fused with 3D-CE T1w were compared by two readers groups for detection of primary diseases and local/distant metastases. Diagnostic performance between the three WB-MRI data sets was assessed using receiver operating characteristic (ROC) curve analysis. Imaging exams and histopathological results were used as standard of references. Results: Areas under the ROC curves of DWIBS vs. 3D-CE-T1w vs. both sequences in fused fashion were 0.97, 0.978, and 1.00, respectively. The diagnostic performance in tumor detection of fused DWIBS/3D-CE-T1w images were statistically superior to DWIBS (p < 0.001) and 3D-CE-T1w (p {<=} 0.002); while the difference between DWIBS and 3D-CE-T1w did not show statistical significance difference. Detection rates of malignancy did not differ between WB-MRI with DWIBS and 18F-FDG PET-CT. Conclusion: WB-MRI with DWIBS is to be considered as alternative tool to conventional whole-body methods for tumor staging and during follow-up in cancer patients.

  18. Software-based geometry operations for 3D computer graphics

    Sima, M.; Iancu, D.; Glossner, J.; Schulte, M.; Mamidi, S.

    2006-01-01

    In order to support a broad dynamic range and a high degree of precision, many of 3D renderings fundamental algorithms have been traditionally performed in floating-point. However, fixed-point data representation is preferable over floatingpoint representation in graphics applications on embedded de

  19. 3D dosimetric verification of IMRT using polymer gel and MRI

    Full text: To investigate the feasibility of using polymer gel for verifying the 3D dose distribution generated by intensity modulated treatment planning. A gel-filled spherical glass phantom was CT-scanned. A C-shaped target that circumscribed an organ at risk was defined and an intensity modulated treatment plan with seven coplanar fields was generated using the Helios software (Varian Medical Systems). Intensity modulation was achieved by the sliding-window technique and irradiation of the phantom was performed using a linear accelerator (Varian 2300 C/D) with a 120 leaf dynamic MLC. The prescribed dose to the target volume was 7.35 Gy (±5%, 7 to 7.7 Gy). The dose to the organ at risk (OAR) was planned to be below 7 Gy and no more than 30% of the OAR volume received above 80% of the prescribed target dose. After irradiation the gel phantom was evaluated in an MR scanner (Magnetom Vision, 1.5 T) using a multi echo sequence and a slice thickness of 3 mm. The measured gel dose distribution was compared with the calculated dose distribution with regard to absorbed dose distribution, dose volume histograms (DVHs) and dose profiles. The separation in absorbed dose between the target region and the OAR is larger for the calculated plan than for the measurement made using polymer gel. This can be seen both in dose distributions, DVHs and dose profiles. There are several factors that can explain these discrepancies, including methods for MR-evaluation, image processing and matching. There are also uncertainties in the calculation of the treatment planning system when the target size is small in relation to the MLC leaves, as is the case in this study. We conclude that the method presented is promising for verification of 3D dose distributions in IMRT applications. However, further studies are needed as well as comparisons with other detector systems such as ionisation chamber, film and TLD. Copyright (2000) Australasian College of Physical Scientists and Engineers in

  20. 3-D cardiac MRI in free-breathing newborns and infants: when is respiratory gating necessary?

    Seeger, Achim [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); University Hospital of Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Tuebingen (Germany); Krumm, Patrick; Schaefer, Juergen F.; Kramer, Ulrich [University Hospital of Tuebingen, Department of Diagnostic and Interventional Radiology, Tuebingen (Germany); Hornung, Andreas; Sieverding, Ludger [University Hospital of Tuebingen, Department of Pediatric Cardiology, Tuebingen (Germany)

    2015-09-15

    Newborns and small infants have shallow breathing. To suggest criteria for when respiratory gating is necessary during cardiac MRI in newborns and infants. One-hundred ten data sets of newborns and infants with (n = 92, mean age: 1.9 ± 1.7 [SD] years) and without (n = 18, mean age: 1.6 ± 1.8 [SD] years) navigator gating were analysed retrospectively. The respiratory motion of the right hemidiaphragm was recorded and correlated to age, weight, body surface area and qualitative image quality on a 4-point score. Quantitative image quality assessment was performed (sharpness of the delineation of the ventricular septal wall) as well as a matched-pair comparison between navigator-gated and non-gated data sets. No significant differences were found in overall image quality or in the sharpness of the ventricular septal wall between gated and non-gated scans. A navigator acceptance of >80% was frequently found in patients ages <12 months, body surface area <0.40 m{sup 2}, body weight <10 kg and a size of <80 cm. Sequences without respiratory gating may be used in newborns and small infants, in particular if age <12 months, body surface area <0.40 m{sup 2}, body weight <10 kg and height <80 cm. (orig.)

  1. 3-D cardiac MRI in free-breathing newborns and infants: when is respiratory gating necessary?

    Newborns and small infants have shallow breathing. To suggest criteria for when respiratory gating is necessary during cardiac MRI in newborns and infants. One-hundred ten data sets of newborns and infants with (n = 92, mean age: 1.9 ± 1.7 [SD] years) and without (n = 18, mean age: 1.6 ± 1.8 [SD] years) navigator gating were analysed retrospectively. The respiratory motion of the right hemidiaphragm was recorded and correlated to age, weight, body surface area and qualitative image quality on a 4-point score. Quantitative image quality assessment was performed (sharpness of the delineation of the ventricular septal wall) as well as a matched-pair comparison between navigator-gated and non-gated data sets. No significant differences were found in overall image quality or in the sharpness of the ventricular septal wall between gated and non-gated scans. A navigator acceptance of >80% was frequently found in patients ages <12 months, body surface area <0.40 m2, body weight <10 kg and a size of <80 cm. Sequences without respiratory gating may be used in newborns and small infants, in particular if age <12 months, body surface area <0.40 m2, body weight <10 kg and height <80 cm. (orig.)

  2. Design and Evaluation of a Fiber-Optic Grip Force Sensor with Compliant 3D-Printable Structure for (fMRI Applications

    Tobias L. Bützer

    2016-01-01

    Full Text Available Grip force sensors compatible with magnetic resonance imaging (MRI are used in human motor control and decision-making research, providing objective and sensitive behavioral outcome measures. Commercial sensors are expensive, cover limited force ranges, rely on pneumatic force transmission that cannot detect fast force changes, or are electrically active, which increases the risk of electromagnetic interference. We present the design and evaluation of a low-cost, 3D-printed, inherently MRI-compatible grip force sensor based on a commercial intensity-based fiber-optic sensor. A compliant monobloc structure with flexible hinges transduces grip force to a linear displacement captured by the fiber-optic sensor. The structure can easily be adapted for different force ranges by changing the hinge thickness. A prototype designed for forces up to 800 N was manufactured and showed a highly linear behavior (nonlinearity of 2.37% and an accuracy of 1.57% in a range between zero and 500 N. It can be printed and assembled within one day and for less than $300. Accurate performance was confirmed, both inside and outside a 3 T MRI scanner within a pilot study. Given its simple design allowing for customization of sensing properties and ergonomics for different applications and requirements, the proposed grip force handle offers researchers a valuable scientific tool.

  3. Automatic training and reliability estimation for 3D ASM applied to cardiac MRI segmentation

    Tobon-Gomez, Catalina; Sukno, Federico M.; Butakoff, Constantine; Huguet, Marina; Frangi, Alejandro F.

    2012-07-01

    Training active shape models requires collecting manual ground-truth meshes in a large image database. While shape information can be reused across multiple imaging modalities, intensity information needs to be imaging modality and protocol specific. In this context, this study has two main purposes: (1) to test the potential of using intensity models learned from MRI simulated datasets and (2) to test the potential of including a measure of reliability during the matching process to increase robustness. We used a population of 400 virtual subjects (XCAT phantom), and two clinical populations of 40 and 45 subjects. Virtual subjects were used to generate simulated datasets (MRISIM simulator). Intensity models were trained both on simulated and real datasets. The trained models were used to segment the left ventricle (LV) and right ventricle (RV) from real datasets. Segmentations were also obtained with and without reliability information. Performance was evaluated with point-to-surface and volume errors. Simulated intensity models obtained average accuracy comparable to inter-observer variability for LV segmentation. The inclusion of reliability information reduced volume errors in hypertrophic patients (EF errors from 17 ± 57% to 10 ± 18% LV MASS errors from -27 ± 22 g to -14 ± 25 g), and in heart failure patients (EF errors from -8 ± 42% to -5 ± 14%). The RV model of the simulated images needs further improvement to better resemble image intensities around the myocardial edges. Both for real and simulated models, reliability information increased segmentation robustness without penalizing accuracy.

  4. Modeling Perception of 3D Forms Using Fuzzy Knowledge Bases

    Achiche, Sofiane; Ahmed, Saeema

    the aesthetics of their products are likely to be perceived are of value. In this paper the authors propose an approach to formalize the relationship between geometric information of a 3D object and the intended perception using fuzzy logic. 3D objects (shapes) created by design engineering students...... to evoke a certain perception were analysed. Three different fuzzy logic models, with different input variables, for evaluating massiveness and lightness in a form are proposed. The uthors identified geometric information as inputs of the fuzzy model and developed a set of fuzzy if/then rules to map...... the relationships between the fuzzy sets on each input premise and the output premise. In our case the output premise of the fuzzy logic model is the level of belonging to the design context (perception). An evaluation of how users perceived the shapes was conducted to validate the fuzzy logic models...

  5. 3D Spatial Data Infrastructures for web-based Visualization

    Schilling, Arne

    2014-01-01

    In this thesis, concepts for developing Spatial Data Infrastructures with an emphasis on visualizing 3D landscape and city models in distributed environments are discussed. Spatial Data Infrastructures are important for public authorities in order to perform tasks on a daily basis, and serve as research topic in geo-informatics. Joint initiatives at national and international level exist for harmonizing procedures and technologies. Interoperability is an important aspect in this context - as ...

  6. Multi-slice CT (MSCT) in cardiac function imaging: threshold-value-supported 3D volume reconstructions to determine the left ventricular ejection fraction in comparison to MRI

    Purpose: To assess MSCT of the heart to determining left ventricular ejection fraction (EF) based on threshold-value-supported 3D volume reconstructions compared to MRI. Methods: Cardiac MSCT was performed in 7 patients. Images were reconstructed during end-systolic and end-diastolic phases of the cardiac cycle and transformed to 3D volumes to determine end-systolic (ESV) and end-diastolic volume (EDV) by using different lower threshold values: besides fixed lower threshold values, identical for each image sequence, individual lower threshold values dependent on contrast enhancement of the left ventricle were applied. The latter represent the mean value calculated by combining the average CT-density of the myocardium and the contrast-enhanced blood in the left ventricle. The EF derived from ESV and EDV. Results: The best correlation with MR imaging was obtained for ESV and EDV by using the individual lower threshold values for the respective sequence. The correlation coefficient for ESV was 0.95 and for EDV it was 0.93. On average, the ESV was overestimated by 3.72 ml, while the ESD was underestimated by 2.85 ml. The respective standard deviation for the ESV was 14,87 ml, for the EDV it was 26.83 ml. On average, the EF was underestimated by 3.57% with a standard deviation of 9.43% and a correlation coefficient of 0.83 in comparison to MRI. Conclusion: The threshold-value-supported 3D volume reconstruction of the left ventricle represents a good method to determine the left ventricular function parameters. Due to the differences in the contrast enhancement, the use of an individual lower threshold value for every image sequence is of particular importance. (orig.)

  7. Value of 3D MRI in the anterior cruciate ligament tear%前交叉韧带损伤的3D MRI诊断价值

    邓军; 梁碧玲; 陈健宇; 钟镜联; 宋玲玲

    2008-01-01

    目的 评价3D MRI在前交叉韧带(ACL)损伤诊断中的价值.方法 对膝关节损伤拟行关节镜检查的病人行术前MRI扫描,46只患膝在常规MRI序列完成后加扫3D MRI序列.在不知道病人信息和病史的情况下先评估常规MR图像,然后评估3D MR图像.评估内容限于ACL完整或撕裂的表现.最后以关节镜检查结果为准,分别计算常规MRI和3D MRI诊断ACI.损伤的敏感性、特异性和准确性.结果 常规MRI诊断ACL损伤的敏感性、特异性和准确性分别为92.0%、95.2%和93.5%;3D MRI诊断ACL损伤的敏感性、特异性和准确性分别为96.0%、100%和97.8%.结论 3DMRI可以提高前交义韧带损伤诊断的敏感性、特异性和准确性.

  8. Single Monocular Moving Camera based 3-D Segmentation

    R. Senthilnathan

    2012-06-01

    Full Text Available Three dimensional (3-D vision techniques in the field of Computer Vision aims mainly at reconstructing a scene to find its three dimensional geometrical information. Passive 3-D vision techniques such as computational stereo vision method do surface reconstruction from disparities arising in images of the same scene taken from multiple views. For reconstruction leading to metrical information of the 3-D geometry of the scene the camera pose with respect to some world reference frame and the camera parameters such as the focal length, sensor size has to be accurately known. Such information especially the pose of the camera might not be known in many applications such as in agricultural, underwater explorations since a unique universal frame of reference is not possible. Also the constancy of the internal camera parameters will not be valid in many applications requiring good accuracy in reconstruction. In such cases the cameras used for passive triangulation is said to be un-calibrated. Stereo vision technique generally requires two images and which need not be from two different cameras. The paper is an attempt to use a single moving camera with which the image of the same scene is acquired from two different views. Since the scene geometry and the pose of the camera are unknown the problem to be addressed is close to so called Structure from Motion (SfM problem in Computer Vision. The reconstruction method developed in the paper is extended further to segment top surfaces of cuboid shaped object considered as the object of interest in the scene reconstruction process. Though the information in the case considered is non-metrical the applications that pose such un-calibrated camera as a demand are plenty.

  9. Camera Based 3D Mine-Shaft Inspection System

    Wohlfeil, Jürgen; Spreckels, Volker; Strackenbrock, Bernhard; Schlienkamp, Andreas; Choinowski, André

    2015-01-01

    This paper describes the development of an Optical 3D Shaft Inspection System needed for the survey and monitoring of Water Handling Shafts in the German Ruhrgebiet. The development is part of the RAG R&D project “ABSMon”. The end of the German hard coal mining at the end of 2018 has been determined with the Steinkohlefinanzierungsgesetz (SteinkohleFinG) from 2007-12-20. About three hundred years before now the near surface hard coal mining began in the southern Ruhr Area an...

  10. Image-Based 3D Face Modeling System

    Vladimir Vezhnevets

    2005-08-01

    Full Text Available This paper describes an automatic system for 3D face modeling using frontal and profile images taken by an ordinary digital camera. The system consists of four subsystems including frontal feature detection, profile feature detection, shape deformation, and texture generation modules. The frontal and profile feature detection modules automatically extract the facial parts such as the eye, nose, mouth, and ear. The shape deformation module utilizes the detected features to deform the generic head mesh model such that the deformed model coincides with the detected features. A texture is created by combining the facial textures augmented from the input images and the synthesized texture and mapped onto the deformed generic head model. This paper provides a practical system for 3D face modeling, which is highly automated by aggregating, customizing, and optimizing a bunch of individual computer vision algorithms. The experimental results show a highly automated process of modeling, which is sufficiently robust to various imaging conditions. The whole model creation including all the optional manual corrections takes only 2∼3 minutes.

  11. A Survey of Recent View-based 3D Model Retrieval Methods

    Liu, Qiong

    2012-01-01

    Extensive research efforts have been dedicated to 3D model retrieval in recent decades. Recently, view-based methods have attracted much research attention due to the high discriminative property of multi-views for 3D object representation. In this report, we summarize the view-based 3D model methods and provide the further research trends. This paper focuses on the scheme for matching between multiple views of 3D models and the application of bag-of-visual-words method in 3D model retrieval....

  12. Design and Evaluation of a Fiber-Optic Grip Force Sensor with Compliant 3D-Printable Structure for (f)MRI Applications

    Bützer, Tobias L.; Rinderknecht, Mike D.; Johannes, Gunda H.; Popp, Werner L.; Rea Lehner; Olivier Lambercy; Roger Gassert

    2016-01-01

    Grip force sensors compatible with magnetic resonance imaging (MRI) are used in human motor control and decision-making research, providing objective and sensitive behavioral outcome measures. Commercial sensors are expensive, cover limited force ranges, rely on pneumatic force transmission that cannot detect fast force changes, or are electrically active, which increases the risk of electromagnetic interference. We present the design and evaluation of a low-cost, 3D-printed, inherently MRI-c...

  13. MRI of the popliteofibular ligament: isotropic 3D WE-DESS versus coronal oblique fat-suppressed T2W MRI

    Rajeswaran, G.; Lee, J.C.; Healy, J.C. [Chelsea and Westminster Hospital, Department of Radiology, London (United Kingdom)

    2007-12-15

    The objective was to compare isotropic 3D water excitation double-echo steady state (WE-DESS) MRI with coronal oblique fat-suppressed T2-weighted (FS T2W) images in the identification of the popliteofibular ligament (PFL). A prospective analysis of 122 consecutive knee MRIs was performed in patients referred for knee pain from the orthopaedic clinic. In addition to the standard knee sequences, isotropic WE-DESS volume acquisition through the whole knee and coronal oblique FS T2W fast spin echo sequences through the posterolateral corner were obtained. The presence of the popliteus and biceps femoris tendons, lateral collateral and PFL was documented. Anterior cruciate ligament injury was present in 33 cases and these were excluded from the study because of the risk of associated PFL injury, leaving a total of 89 cases. Of the 42 patients in whom arthroscopic evaluation was subsequently obtained, none were found to have an injury to the PFL. The lateral collateral ligament, biceps femoris and popliteus tendon were identified in all cases on all sequences. The PFL was seen in 81 (91.0%; 95% CI 85.1-97.0%) patients using the WE-DESS sequence and 63 (70.8%; 95% CI 61.3-80.2%) patients using the coronal oblique FS T2W sequence, a statistically significant difference (p < 0.00005). Isotropic 3D WE-DESS MRI significantly enhances our ability to identify the popliteofibular ligament compared with coronal oblique fat-suppressed T2-weighted images. (orig.)

  14. 3-D Adaptive Sparsity Based Image Compression With Applications to Optical Coherence Tomography.

    Fang, Leyuan; Li, Shutao; Kang, Xudong; Izatt, Joseph A; Farsiu, Sina

    2015-06-01

    We present a novel general-purpose compression method for tomographic images, termed 3D adaptive sparse representation based compression (3D-ASRC). In this paper, we focus on applications of 3D-ASRC for the compression of ophthalmic 3D optical coherence tomography (OCT) images. The 3D-ASRC algorithm exploits correlations among adjacent OCT images to improve compression performance, yet is sensitive to preserving their differences. Due to the inherent denoising mechanism of the sparsity based 3D-ASRC, the quality of the compressed images are often better than the raw images they are based on. Experiments on clinical-grade retinal OCT images demonstrate the superiority of the proposed 3D-ASRC over other well-known compression methods. PMID:25561591

  15. Research on urban rapid 3D modeling and application based on CGA rule

    Li, Jing-wen; Jiang, Jian-wu; Zhou, Song; Yin, Shou-qiang

    2015-12-01

    Use CityEngine as the 3D modeling platform, research on urban rapid 3D modeling technology based on the CGA(Computer Generated Architectur) rule , solved the problem of the rapid creation of urban 3D model in large scenes , and research on building texture processing and 3D model optimization techniques based on CGA rule , using component modeling method , solved the problem of texture distortion and model redundancy in the traditional fast modeling 3D model , and development of a three-dimensional view and analysis system based on ArcGIS Engine , realization of 3D model query , distance measurement , specific path flight , 3D marking , Scene export,etc.

  16. 3D Image Sensor based on Parallax Motion

    Barna Reskó

    2007-12-01

    Full Text Available For humans and visual animals vision it is the primary and the most sophisticatedperceptual modality to get information about the surrounding world. Depth perception is apart of vision allowing to accurately determine the distance to an object which makes it animportant visual task. Humans have two eyes with overlapping visual fields that enablestereo vision and thus space perception. Some birds however do not have overlappingvisual fields, and compensate this lask by moving their heads, which in turn makes spaceperception possible using the motion parallax as a visual cue. This paper presents asolution using an opto-mechanical filter that was inspired by the way birds observe theirenvironment. The filtering is done using two different approaches:using motion blur duringmotion parallax, and using the optical flow algorithm. The two methods have differentadvantages and drawbacks, which will be discussed in the paper. The proposed system canbe used in robotics for 3D space perception.

  17. 3D transient calculations of PGV-1000 based on TRAC

    Anatoly A Kazantsev; Andrey N Pozdnyakov [Simulation Systems Ltd., 133-208 Lenin str. 249030, Obninsk city, Kaluga reg. (Russian Federation); Vladimir V Sergeev; Valery A Evstifeev [Institute of Physics and Power Engineering (IPPE) 249020, Bondarenko square 1, Obninsk city, Kaluga reg., Russia, Government research center RF IPPE by A.I. Leipynski (Russian Federation)

    2005-07-01

    Full text of publication follows: During calculations of SAR accidents and transients it is necessary to perform steam generator simulation. Best accuracy is 3D transient calculations presented in report. Main outcomes of work was next: 1. There was shown by analysis the applicability of code TRAC (Los-Alamos laboratory) for thermal - hydraulic calculations of horizontal steam generator PGV-1000M. Special nodalization scheme was developed for it purposes. 2. Validation and selection of thermal-hydraulic correlations for improvement of using the code at calculation PGV-1000M were performed. As result Labuntsov formula is recommended for horizontal SG. 3. Calculations of nominal mode operation of PGV-1000M for cross-verification with code STEG (Electrogorsk Research and Engineering Center EREC) during its verification were performed. Solution by TRAC was obtained for transient problem after stabilization time. 4. Development of dynamic SG model as conjugate problem (thermal hydraulic of I and II circuits are calculated together) for research of the transient and accident processes stipulated by safety standards for NPP with VVER-1000 and VVER-1500. 5. Creating of calculation complex on the basis of code TRAC for the purposes of the analysis and optimization of a design. Development graphic pre- and post-processor for code TRAC. 6. The TRAC code allows to use correlation Zukauskas for friction factors in tube bundles through the initial data. Using postprocessing calculations and restart mode iterations allows to use Kolbasnikov's correlations for friction factors for biphasic mode in tube bundles. Developed nodalization model of PGV-1000M includes a conjugate hydrodynamical problem on I and to II circuits in view of thermal connection through packages of tubes. Thus primary circuit is considered in multichannel 1D approximation with hydraulic non-uniformity of flow rates between pre-settled groups of tubes. The hydrodynamics into shell of PG is presented as 3D

  18. Mobile gaze-based screen interaction in 3D environments

    Mardanbeigi, Diako; Witzner Hansen, Dan

    2011-01-01

    Head-mounted eye trackers can be used for mobile interaction as well as gaze estimation purposes. This paper presents a method that enables the user to interact with any planar digital display in a 3D environment using a head-mounted eye tracker. An effective method for identifying the screens in...... the field of view of the user is also presented which can be applied in a general scenario in which multiple users can interact with multiple screens. A particular application of using this technique is implemented in a home environment with two big screens and a mobile phone. In this application a...... user was able to interact with these screens using a wireless head-mounted eye tracker....

  19. 3D Wavelet-based Fusion Techniques for Biomedical Imaging

    Rubio Guivernau, José Luis

    2012-01-01

    Hoy en día las técnicas de adquisición de imágenes tridimensionales son comunes en diversas áreas, pero cabe destacar la relevancia que han adquirido en el ámbito de la imagen biomédica, dentro del cual encontramos una amplia gama de técnicas como la microscopía confocal, microscopía de dos fotones, microscopía de fluorescencia mediante lámina de luz, resonancia magnética nuclear, tomografía por emisión de positrones, tomografía de coherencia óptica, ecografía 3D y un largo etcétera. Un denom...

  20. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene

    Wang, Xin-yun; Guo, Zhi-feng; Qin, Wen-han; Sun, Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale. Simplified coniferous model was investigate d in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerf ul in remote sensing of heterogeneous coniferous forests over a large -scale region. L-systems is applied to render 3-D coniferous forest scenarios: and RGM model was used to calculate BRF (bidirectional refle ctance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhiie at a tree and forest level. the results are also good.

  1. 3D-MRCP与Balance-FFE及常规MRI序列联合应用诊断梗阻性黄疸%3D-MRCP, Balance-FFE combined with routine MRI examination in diagnosis of obstructive jaundice

    唐敏; 王坤; 靳晶; 朱斌

    2012-01-01

    Objective To evaluate the value of 3D-MRCP, Balance-FFE combined with routine MRI examination in the diagnosis of obstructive jaundice. Methods The MRI exams of 156 patients with obstructive jaundice proved by operation were analyzed. Results The study participants were classified into 3 groups; stone disease into group Ⅰ, tumor into group Ⅱ and others into group Ⅲ. 3D-MRCP, Balance_FFE combined with routine MRI examination had 100%, 80. 3% .and 100% corresponding diagnostic rates in group Ⅰ, group Ⅱ , group Ⅲ respectively. The total corresponding diagnostic rate was 92. 9%. Conclusion By analyzing the direct signs and indirect signs, 3D-MRCP, Balance-FFE combined with routine MRI examination can improve the diagnostic accuracy of obstructive jaundice.%目的 评价3D-Magnetic Resonance Cholangiopancreatography(MRCP)与Balance fast field echo(BalanceFFE)及常规MRI序列联合应用对梗阻性黄疸的诊断价值.方法 156例梗阻性黄疸患者行包括3D-MRCP、冠状位BFFE、抽位TIWI、T2WI、T2压脂,部分行同层动态增强检查.所有影像诊断结果与最终手术病理结果进行回顾对照分析.结果 156例病人分为3组,组Ⅰ结石94例,组Ⅱ肿瘤56例,组Ⅲ其它6例.3D-MRCP、B-FFE与常规MRI联合应用,定性诊断的符合率分别为100%、80.3%和100%,总符合率为92.9%.结论 3D-MRCP、B-FFE与常规MRI扫描序列联合应用通过观察直接征象和间接征象,对梗阻性黄疸的定性诊断有较高准确性.

  2. Math World: A Game-Based 3D Virtual Learning Environment (3D VLE for Second Graders

    Jean Maitem

    2012-02-01

    Full Text Available This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured in terms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement the conventional approaches of teaching.

  3. Math World: A Game-Based 3D Virtual Learning Environment (3D VLE for Second Graders

    Jean Maitem

    2012-03-01

    Full Text Available This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured interms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement the conventional approaches of teaching.

  4. Math world: A game-based 3D Virtual Learning Environment (3D VLE) for second graders

    Maitem, Jean; Rabago, Lorena; Tanguilig, Bartolome

    2012-01-01

    This paper intends to introduce a game-based 3D Virtual Learning Environment (VLE) to second graders. The impetus arose from the need to make learning in mathematics more effective and interesting through multimedia. Applied in a game, the basic mathematical operations such as addition, subtraction, multiplication, and division are expected to performed by learners as they represent themselves as avatars while they immerse in a quest of digital objects in the VLE called Math World. Educational attributes such as mentality change, emotional fulfillment, knowledge enhancement, thinking skills development, and bodily coordination are evaluated to ensure learning effectiveness. Also, game playability measured in terms of game plays, story, mechanics and interface usability are examined for its educative design. With an aggregate of these enhanced indices, results attest that objectives were met while making mathematics an interesting, motivating and enjoyable subject, hence VLE a significant tool to complement th...

  5. 3D-SPGR序列在脑肿瘤MRI中的应用%The Application of MRI 3D-SPGR Sequence in Brain Tumor

    李长青

    2000-01-01

    @@ 脑肿瘤是磁共振成像中较常见的肿瘤,当前应用于脑肿瘤的MR技术主要是二维的SE序列,笔者通过对41例患者行3D-SPGR序列扫描,试图评价该序列在脑肿瘤MRI的应用价值.

  6. An Overview of 3d Topology for Ladm-Based Objects

    Zulkifli, N. A.; Rahman, A. A.; van Oosterom, P.

    2015-10-01

    This paper reviews 3D topology within Land Administration Domain Model (LADM) international standard. It is important to review characteristic of the different 3D topological models and to choose the most suitable model for certain applications. The characteristic of the different 3D topological models are based on several main aspects (e.g. space or plane partition, used primitives, constructive rules, orientation and explicit or implicit relationships). The most suitable 3D topological model depends on the type of application it is used for. There is no single 3D topology model best suitable for all types of applications. Therefore, it is very important to define the requirements of the 3D topology model. The context of this paper is a 3D topology for LADM-based objects.

  7. TU-F-17A-04: Respiratory Phase-Resolved 3D MRI with Isotropic High Spatial Resolution: Determination of the Average Breathing Motion Pattern for Abdominal Radiotherapy Planning

    Purpose: To develop a retrospective 4D-MRI technique (respiratory phase-resolved 3D-MRI) for providing an accurate assessment of tumor motion secondary to respiration. Methods: A 3D projection reconstruction (PR) sequence with self-gating (SG) was developed for 4D-MRI on a 3.0T MRI scanner. The respiration-induced shift of the imaging target was recorded by SG signals acquired in the superior-inferior direction every 15 radial projections (i.e. temporal resolution 98 ms). A total of 73000 radial projections obtained in 8-min were retrospectively sorted into 10 time-domain evenly distributed respiratory phases based on the SG information. Ten 3D image sets were then reconstructed offline. The technique was validated on a motion phantom (gadolinium-doped water-filled box, frequency of 10 and 18 cycles/min) and humans (4 healthy and 2 patients with liver tumors). Imaging protocol included 8-min 4D-MRI followed by 1-min 2D-realtime (498 ms/frame) MRI as a reference. Results: The multiphase 3D image sets with isotropic high spatial resolution (1.56 mm) permits flexible image reformatting and visualization. No intra-phase motion-induced blurring was observed. Comparing to 2D-realtime, 4D-MRI yielded similar motion range (phantom: 10.46 vs. 11.27 mm; healthy subject: 25.20 vs. 17.9 mm; patient: 11.38 vs. 9.30 mm), reasonable displacement difference averaged over the 10 phases (0.74mm; 3.63mm; 1.65mm), and excellent cross-correlation (0.98; 0.96; 0.94) between the two displacement series. Conclusion: Our preliminary study has demonstrated that the 4D-MRI technique can provide high-quality respiratory phase-resolved 3D images that feature: a) isotropic high spatial resolution, b) a fixed scan time of 8 minutes, c) an accurate estimate of average motion pattern, and d) minimal intra-phase motion artifact. This approach has the potential to become a viable alternative solution to assess the impact of breathing on tumor motion and determine appropriate treatment margins

  8. TU-F-17A-04: Respiratory Phase-Resolved 3D MRI with Isotropic High Spatial Resolution: Determination of the Average Breathing Motion Pattern for Abdominal Radiotherapy Planning

    Deng, Z; Pang, J; Yang, W; Yue, Y; Tuli, R; Fraass, B; Li, D; Fan, Z [Cedars-Sinai Medical Center, Los Angeles, CA (United States)

    2014-06-15

    Purpose: To develop a retrospective 4D-MRI technique (respiratory phase-resolved 3D-MRI) for providing an accurate assessment of tumor motion secondary to respiration. Methods: A 3D projection reconstruction (PR) sequence with self-gating (SG) was developed for 4D-MRI on a 3.0T MRI scanner. The respiration-induced shift of the imaging target was recorded by SG signals acquired in the superior-inferior direction every 15 radial projections (i.e. temporal resolution 98 ms). A total of 73000 radial projections obtained in 8-min were retrospectively sorted into 10 time-domain evenly distributed respiratory phases based on the SG information. Ten 3D image sets were then reconstructed offline. The technique was validated on a motion phantom (gadolinium-doped water-filled box, frequency of 10 and 18 cycles/min) and humans (4 healthy and 2 patients with liver tumors). Imaging protocol included 8-min 4D-MRI followed by 1-min 2D-realtime (498 ms/frame) MRI as a reference. Results: The multiphase 3D image sets with isotropic high spatial resolution (1.56 mm) permits flexible image reformatting and visualization. No intra-phase motion-induced blurring was observed. Comparing to 2D-realtime, 4D-MRI yielded similar motion range (phantom: 10.46 vs. 11.27 mm; healthy subject: 25.20 vs. 17.9 mm; patient: 11.38 vs. 9.30 mm), reasonable displacement difference averaged over the 10 phases (0.74mm; 3.63mm; 1.65mm), and excellent cross-correlation (0.98; 0.96; 0.94) between the two displacement series. Conclusion: Our preliminary study has demonstrated that the 4D-MRI technique can provide high-quality respiratory phase-resolved 3D images that feature: a) isotropic high spatial resolution, b) a fixed scan time of 8 minutes, c) an accurate estimate of average motion pattern, and d) minimal intra-phase motion artifact. This approach has the potential to become a viable alternative solution to assess the impact of breathing on tumor motion and determine appropriate treatment margins

  9. A new approach towards image based virtual 3D city modeling by using close range photogrammetry

    S. P. Singh; K. Jain; V. R. Mandla

    2014-01-01

    3D city model is a digital representation of the Earth's surface and it’s related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing day to day for various engineering and non-engineering applications. Generally three main image based approaches are using for virtual 3D city models generation. In first approach, researchers used Sketch based modeling, second method is Procedural grammar based m...

  10. Diagnostic System for 3D Ultrasonography Based on Gabor Filter

    Wei-Ming Chen

    2010-12-01

    Full Text Available 800x600 Normal 0 0 2 false false false EN-US ZH-TW X-NONE MicrosoftInternetExplorer4 With the development of the times, people's lifestyle and eating habits are changed a lot. Worldwide, breast cancer is the second most common type of cancer after lung cancer and the fifth most common cause of cancer death. Diagnostic ultrasound (US of breast cancer is currently the major clinical detection method. It is recognized as a safe, effective, and highly flexible imaging modality capable of providing clinically relevant information about most parts of the body in a rapid and cost-effective fashion. However, ultrasound imaging usually contains a large number of noises and speckles. That will impact greatly on diagnosis by physicians. Therefore, we proposed a method to enhance the computer-aided diagnosis (CAD of the breast cancer tumors and to reduce detection time and error rate. Experimental investigations demonstrated that the texture variance of 3D ultrasound were effective and useful for differential diagnosis of breast tumors. Texture extraction with proposed method can find malignant more accurate than auto-correlation.