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Image Reconstruction

Shixin Wang, Ye Tian, Yi Zhou, Wenliang Liu, Chenxi Lin
Fine-scale population estimation is essential in emergency response and epidemiological applications as well as urban planning and management. However, representing populations in heterogeneous urban regions with a finer resolution is a challenge. This study aims to obtain fine-scale population distribution based on 3D reconstruction of urban residential buildings with morphological operations using optical high-resolution (HR) images from the Chinese No. 3 Resources Satellite (ZY-3). Specifically, the research area was first divided into three categories when dasymetric mapping was taken into consideration...
October 21, 2016: Sensors
Jaka Kravanja, Mario Žganec, Jerneja Žganec-Gros, Simon Dobrišek, Vitomir Štruc
Depth image acquisition with structured light approaches in outdoor environments is a challenging problem due to external factors, such as ambient sunlight, which commonly affect the acquisition procedure. This paper presents a novel structured light sensor designed specifically for operation in outdoor environments. The sensor exploits a modulated sequence of structured light projected onto the target scene to counteract environmental factors and estimate a spatial distortion map in a robust manner. The correspondence between the projected pattern and the estimated distortion map is then established using a probabilistic framework based on graphical models...
October 19, 2016: Sensors
Eugenio Ivorra, Samuel Verdu, Antonio J Sánchez, Raúl Grau, José M Barat
A technique that combines the spatial resolution of a 3D structured-light (SL) imaging system with the spectral analysis of a hyperspectral short-wave near infrared system was developed for freshness predictions of gilthead sea bream on the first storage days (Days 0-6). This novel approach allows the hyperspectral analysis of very specific fish areas, which provides more information for freshness estimations. The SL system obtains a 3D reconstruction of fish, and an automatic method locates gilthead's pupils and irises...
October 19, 2016: Sensors
Yongwei Nie, Zhensong Zhang, Hanqiu Sun, Tan Su, Guiqing Li
Wide-baseline street image interpolation is useful but very challenging. Existing approaches either rely on heavyweight 3D reconstruction or computationally intensive deep networks. We present a lightweight and efficient method which uses simple homography computing and refining operators to estimate piecewise smooth homographies between input views. To achieve the goal, we show how to combine homography fitting and homography propagation together based on reliable and unreliable superpixel discrimination. Such a combination, other than using homography fitting only, dramatically increases the accuracy and robustness of the estimated homographies...
October 19, 2016: IEEE Transactions on Visualization and Computer Graphics
Pierre Buyssens, Olivier le Meur, Maxime Daisy, David Tschumperle, Olivier Lezoray
We propose to tackle the problem of RGB-D image disocclusion inpainting when synthesizing new views of a scene by changing its viewpoint. Indeed, such a process creates holes both in depth and color images. First, we propose a novel algorithm to perform depth-map disocclusion inpainting. Our intuitive approach works particularly well for recovering the lost structures of the objects and to inpaint the depth-map in a geometrically plausible manner. Then, we propose a depth-guided patch based inpainting method to fill-in the color image...
October 19, 2016: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Ram Iyer, Farzana Nasrin, Elton See, Steven Mathews
Optical coherence tomography (OCT) is a non-invasive imaging technique used to study and understand internal structures of biological tissues such as the anterior chamber of the human eye. An interesting problem is the reconstruction of the shape of the biological tissue from OCT images, that is not only a good fit of the data but also respects the smoothness properties observed in the images. A similar problem arises in Magnetic Resonance Imaging (MRI). We cast the problem as a penalized weighted least squares regression with a penalty on the magnitude of the second derivative (Laplacian) of the surface...
October 19, 2016: IEEE Transactions on Medical Imaging
Thobias Romu, Nils Dahlström, Olof Dahlqvist Leinhard, Magnus Borga
PURPOSE: The purpose of this work was to develop and evaluate a robust water-fat separation method for T1-weighted symmetric two-point Dixon data. THEORY AND METHODS: A method for water-fat separation by phase unwrapping of the opposite-phase images by phase-sensitive reconstruction (PSR) is introduced. PSR consists of three steps; (1), identification of clusters of tissue voxels; (2), unwrapping of the phase in each cluster by solving Poisson's equation; and (3), finding the correct sign of each unwrapped opposite-phase cluster, so that the water-fat images are assigned the correct identities...
October 24, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Franciszek Hennel, Klaas P Pruessmann
PURPOSE: Fourier encoded MRI signal is complex and, therefore, sensitive to uncontrolled phase variations caused, e.g., by object motion. An alternative encoding is proposed which leads to phaseless (positive real) signals and allows the phase fluctuations to be removed by simple magnitude calculation before the Fourier transform. THEORY AND METHODS: Phaseless encoding uses harmonic modulation of the longitudinal magnetization with different frequencies and phases before excitation...
October 23, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Rushin Shojaii, Anne L Martel
The registration of two-dimensional histology images to reference images from other modalities is an important preprocessing step in the reconstruction of three-dimensional histology volumes. This is a challenging problem because of the differences in the appearances of histology images and other modalities, and the presence of large nonrigid deformations which occur during slide preparation. This paper shows the feasibility of using densely sampled scale-invariant feature transform (SIFT) features and a SIFTFlow deformable registration algorithm for coregistering whole-mount histology images with blockface optical images...
October 2016: Journal of Medical Imaging
Yubin Liu, Yating Wang, Zhen Yuan
We developed a homemade dual-modality imaging system that combines multispectral photoacoustic computed tomography and ultrasound computed tomography for reconstructing the structural and functional information of human finger joint systems. The fused multispectral photoacoustic-ultrasound computed tomography (MPAUCT) system was examined by the phantom and in vivo experimental tests. The imaging results indicate that the hard tissues such as the bones and the soft tissues including the blood vessels, the tendon, the skins, and the subcutaneous tissues in the finger joints systems can be effectively recovered by using our multimodality MPAUCT system...
2016: BioMed Research International
Jagdish C Mohan, Madhu Shukla, Vishwas Mohan, Arvind Sethi
BACKGROUND: Congenital anomaly wherein the mitral valve leaflets are directly attached to the papillary muscle(s) (PM) with or without short under-developed chords is rarely reported in adults. Patients with two PMs with an intervening fibrous bridge have also been included under this head in previous studies. METHODS: Echocardiography enables accurate evaluation of the morphology and function of valve leaflets, chordae tendineae, and PM. This report describes a series of six patients aged 56-84 years who had abnormal mitral valve with a large solitary and anomalously inserted PM seen over a period of 3 years...
September 2016: Indian Heart Journal
Bhanu Gogia, Vinodh A Kumar, Lakshmi S Chavali, Leena Ketonen, Jill Hunter, Sujit S Prabhu, Donald Schomer, L Anne Hayman
PURPOSE: Our purpose is to describe the thalamic veins using a novel approach named venous gliography in cases with primary or secondary gliomas of the thalamus. Venous gliography is defined by authors as a method to visualize veins on MRI Brain T1-weighted post contrast scans containing gliomas which have induced regional venous congestion. METHODS: Routine clinical MR Imaging studies were reviewed to assess the presence of thalamic veins in 29 glioma cases. In addition, confocal reconstruction techniques (Anatom-e and Osirix) were used in cases that had thin sections (1...
November 15, 2016: Journal of the Neurological Sciences
Chan-Yang Hsu, Jin-Chung Shih, Shyh-Jye Chen, En-Ting Wu, Chun-Wei Lu, Yih-Sharng Chen, Shu-Chien Huang
We report a modified Norwood stage I procedure for tricuspid atresia, transposition of great arteries, and hypoplastic right aortic arch with complete vascular ring. In this technique, we applied dual arterial cannulation to avoid circulation arrest during neoaortic reconstruction, and also corrected the arch laterality during the Norwood stage I palliation procedure. Pulmonary flow was supplied by the Blalock-Taussig shunt. Postoperative imaging revealed the patent left neoaortic arch, and the vascular ring was relieved with a patent tracheobronchial tree...
November 2016: Annals of Thoracic Surgery
Wei-Bing Wu, Xin-Feng Xu, Wei Wen, Jing Xu, Quan Zhu, Liang Chen
Thoracoscopic anatomic pulmonary segmentectomy and subsegmentectomy have become sophisticated surgical solutions for complex pulmonary diseases. The rapid development of three-dimensional computed tomographic angiography (3DCTA) has made it possible to provide more refined individualized anatomic details and has consequently enabled subsubsegmentectomy (SSS). In this study, we report two successful thoracoscopic anatomic SSSs of the left S(1+2)aii and S(3)aii under the guidance of 3DCTA reconstructed images...
November 2016: Annals of Thoracic Surgery
Bertram J Wilm, Christoph Barmet, Simon Gross, Lars Kasper, S Johanna Vannesjo, Max Haeberlin, Benjamin E Dietrich, David O Brunner, Thomas Schmid, Klaas P Pruessmann
PURPOSE: The purpose of this work was to improve the quality of single-shot spiral MRI and demonstrate its application for diffusion-weighted imaging. METHODS: Image formation is based on an expanded encoding model that accounts for dynamic magnetic fields up to third order in space, nonuniform static B0 , and coil sensitivity encoding. The encoding model is determined by B0 mapping, sensitivity mapping, and concurrent field monitoring. Reconstruction is performed by iterative inversion of the expanded signal equations...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Stephen F Cauley, Kawin Setsompop, Berkin Bilgic, Himanshu Bhat, Borjan Gagoski, Lawrence L Wald
PURPOSE: Fast MRI acquisitions often rely on efficient traversal of k-space and hardware limitations, or other physical effects can cause the k-space trajectory to deviate from a theoretical path in a manner dependent on the image prescription and protocol parameters. Additional measurements or generalized calibrations are typically needed to characterize the discrepancies. We propose an autocalibrated technique to determine these discrepancies. METHODS: A joint optimization is used to estimate the trajectory simultaneously with the parallel imaging reconstruction, without the need for additional measurements...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
T J Tan, Kenneth K Lau, Dana Jackson, Nicholas Ardley, Adina Borasu
The purpose of this study was to assess the efficacy of model-based iterative reconstruction (MBIR), statistical iterative reconstruction (SIR), and filtered back projection (FBP) image reconstruction algorithms in the delineation of ureters and overall image quality on non-enhanced computed tomography of the renal tracts (NECT-KUB). This was a prospective study of 40 adult patients who underwent NECT-KUB for investigation of ureteric colic. Images were reconstructed using FBP, SIR, and MBIR techniques and individually and randomly assessed by two blinded radiologists...
October 21, 2016: Emergency Radiology
J L Vilas, J Navas, J Gómez-Blanco, J M de la Rosa-Trevín, R Melero, I Peschiera, I Ferlenghi, J Cuenca, R Marabini, J M Carazo, J Vargas, C O S Sorzano
Random conical tilt (RCT) and orthogonal tilt reconstruction (OTR) are two remarkable methods for reconstructing the three-dimensional structure of macromolecules at low resolution. These techniques use two images at two different sample tilts. One of the most demanding steps in these methods at the image processing level is to identify corresponding particles on both micrographs, and manual or semiautomatic matching methods are usually used. Here we present an approach to solve this bottleneck with a fully automatic method for assigning particle tilt pairs...
October 18, 2016: Journal of Structural Biology
Helle Precht, Pieter H Kitslaar, Alexander Broersen, Jouke Dijkstra, Oke Gerke, Jesper Thygesen, Kenneth Egstrup, Jess Lambrechtsen
PURPOSE: The purpose of this study was to study the effect of iterative reconstruction (IR) software on quantitative plaque measurements in coronary computed tomography angiography (CCTA). METHODS: Thirty patients with a three clinical risk factors for coronary artery disease (CAD) had one CCTA performed. Images were reconstructed using FBP, 30% and 60% adaptive statistical IR (ASIR). Coronary plaque analysis was performed as per patient and per vessel (LM, LAD, CX and RCA) measurements...
September 28, 2016: Journal of Cardiovascular Computed Tomography
You-Na Lee, Koichi Okumura, Tatsuya Iwata, Kazuhiro Takahashi, Toshiaki Hattori, Makoto Ishida, Kazuaki Sawada
A bio-image sensor using a patterned apyrase-immobilized membrane was developed to visualize the activities of adenosine triphosphate (ATP) and H(+) ion in real-time. An enzymatic membrane patterning technique was suggested to immobilize apyrase on a specific sensing area of a charge coupled device (CCD)-type image sensor. It was able to observe the spatiotemporal information of ATP and H(+) ion. The smallest size of a patterned membrane is 250×250µm(2). The fabrication parameters of the patterned membrane, such as its thickness and the intensity of the incident light used for photolithography, were optimized experimentally...
December 1, 2016: Talanta
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