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Image Reconstruction

Aida Niñerola-Baizán, Judith Gallego, Albert Cot, Pablo Aguiar, Francisco Lomeña, Javier Pavía, Domenec Ros
The aim of this work was to obtain a set of parameters to be applied in [123I]FP-CIT SPECT reconstruction in order to minimize the error between standardized and true values of the Specific Uptake Ratio (SUR) in dopaminergic neurotransmission SPECT studies. To this end, Monte Carlo simulation was used to generate a database of 1,380 projection data-sets from 23 subjects, including normal cases and a variety of pathologies. Studies were reconstructed using Filtered Back Projection (FBP) with attenuation correction and Ordered Subset Expectation Maximization (OSEM) with correction for different degradations (attenuation, scatter and PSF)...
March 19, 2018: Physics in Medicine and Biology
Muhammad Sohail Umerani, Hira Burhan, Salman Sharif, Tauqir Ul Islam, Mehak Hafiz Ghaziani
Orbital roof defects are rare congenital osseous abnormalities that cause protrusion of intracranial contents into the orbit, resulting in a condition known as the orbital meningoencephalocele, a rare cause of pulsatile proptosis. We present a case of a 25-year-old lady, presented to us with complaints of left frontal headache, left eye protrusion and double vision from the left eye for the past three months. Her higher mental functions were intact. Local examination revealed non-axial pulsatile proptosis and an outward depression of the left eyeball along with diplopia...
January 15, 2018: Curēus
Pu Wang, Gianluca Turcatel, Cosimo Arnesano, David Warburton, Scott E Fraser, Francesco Cutrale
Hyperspectral endoscopic imaging has the potential to enhance clinical diagnostics and outcome. Most commercial endoscopes utilize imaging fiber bundles to transmit the collected signal from the patient to the medical operator. These bundles consist of several fiber cores surrounded by a cladding layer creating comb structure-like artifacts, which complicate further analysis, both spatially and spectrally. Here we present an optical fiber pattern removal algorithm which we applied to hyperspectral bronchoscopic images robustly and quantitatively without the need for specific optical or electrical hardware...
February 1, 2018: Biomedical Optics Express
Hyung-Jin Kim, Minji Kim, Min Gyu Hyeon, Youngwoon Choi, Beop-Min Kim
We propose a new method of determining the optical axis (OA), pupillary axis (PA), and visual axis (VA) of the human eye by using dual-depth whole-eye optical coherence tomography (OCT). These axes, as well as the angles "α" between the OA and VA and "κ" between PA and VA, are important in many ophthalmologic applications, especially in refractive surgery. Whole-eye images are reconstructed based on simultaneously acquired images of the anterior segment and retina. The light from a light source is split into two orthogonal polarization components for imaging the anterior segment and retina, respectively...
February 1, 2018: Biomedical Optics Express
Masafumi Nakayama, Masaharu Hirano, Sonoka Goto, Akifumi Watanabe, Takashi Uchiyama
A 40-year-old man was admitted to our hospital for chest pain after smoking. Coronary computed tomography angiography showed severe stenosis in the left anterior descending artery. The stenosis site had no plaque on stretched curved multiplanar reconstruction and short-axis images. Coronary angiography revealed improvement of the severe stenosis after the intracoronary administration of isosorbide dinitrate in the left anterior descending artery. Intravascular ultrasound demonstrated negative remodeling without a plaque and diffuse intima with media thickening at the stenosis site...
February 2018: Radiology Case Reports
Quanying Liu, Marco Ganzetti, Nicole Wenderoth, Dante Mantini
Resting state networks (RSNs) in the human brain were recently detected using high-density electroencephalography (hdEEG). This was done by using an advanced analysis workflow to estimate neural signals in the cortex and to assess functional connectivity (FC) between distant cortical regions. FC analyses were conducted either using temporal (tICA) or spatial independent component analysis (sICA). Notably, EEG-RSNs obtained with sICA were very similar to RSNs retrieved with sICA from functional magnetic resonance imaging data...
2018: Frontiers in Neuroinformatics
Mandy Berndt-Paetz, Luise Herbst, Annett Weimann, Andreas Gonsior, Jens-Uwe Stolzenburg, Jochen Neuhaus
PURPOSE: Muscarinic acetylcholine receptors (mAChRs) regulate a number of important physiological functions. Alteration of mAChR expression or function has been associated in the etiology of several pathologies including functional bladder disorders (e.g bladder pain syndrome/interstitial cystitis - BPS/IC). In a previous study we found specific mAChR expression patterns associated with BPS/IC, while correlation between protein and gene expression was lacking. Posttranslational regulatory mechanisms, e...
March 15, 2018: Acta Histochemica
Linda C Chu, Pamela T Johnson, Elliot K Fishman
Pancreatic cancer is the third most common cause of cancer death and CT is the most commonly used modality for the initial evaluation of suspected pancreatic cancer. Post-processing of CT data into 2D multiplanar and 3D reconstructions has been shown to improve tumor visualization and assessment of tumor resectability compared to axial slices, and is considered the standard of care. Cinematic rendering is a new 3D-rendering technique that produces photorealistic images, and it has the potential to more accurately depict anatomic detail compared to traditional 3D reconstruction techniques...
March 17, 2018: Abdominal Radiology
Salahaddin Zahedi, Maryam Mostafavi, Neda Lotfirikan
INTRODUCTION: The present study aimed to anatomically assess mandibular posterior teeth using cone-beam computed tomographic (CBCT) imaging for endodontic surgery. METHODS: A total of 170 CBCT scans were evaluated for anatomic variations of mandibular posterior teeth. All the scans were obtained using a Planmeca Promax CBCT unit (Planmeca, Helsinki, Finland) with exposure settings of 90 kVp, 12 mA, 12 seconds, and 0.3-mm resolution. All CBCT images were reconstructed by Romexis Viewer 3...
March 14, 2018: Journal of Endodontics
Cheng-Hsin Cheng, Hao-Yu Chuang, Hung-Lin Lin, Chun-Lin Liu, Chun-Hsu Yao
OBJECT: The aim of this research was to evaluate the surgical outcome of a new three-dimensional printing (3DP) technique using prefabrication molds and polymethyl methacrylate (PMMA). PATIENTS AND METHODS: The study included 10 patients with large skull defects (>100 cm2 ) who underwent cranioplasty. The causes of the skull defects were trauma (6), bone resorption (2), tumor (1), and infection (1). Before the operation, computed tomography (CT) scans were used to create a virtual plan, and these were then converted to 3-dimensional (3-D) images...
March 9, 2018: Clinical Neurology and Neurosurgery
Sa Xiao, He Deng, Caohui Duan, Junshuai Xie, Huiting Zhang, Xianping Sun, Chaohui Ye, Xin Zhou
Dynamic hyperpolarized (HP)129 Xe MRI is able to visualize the process of lung ventilation, which potentially provides unique information about lung physiology and pathophysiology. However, the longitudinal magnetization of HP129 Xe is nonrenewable, making it difficult to achieve high image quality while maintaining high temporal-spatial resolution in the pulmonary dynamic MRI. In this paper, we propose a new accelerated dynamic HP129 Xe MRI scheme incorporating the low-rank, sparse and gas-inflow effects (L + S + G) constraints...
March 8, 2018: Journal of Magnetic Resonance
J-P Suuronen, M Sayab
Zircon is the most widely used mineral in petrochronology and provides key information about magmatic and crustal differentiation history of plutonic rocks, transport paths of clastic material 'from source to sink' and significantly contributes in the reconstruction of enigmatic planetary-scale tectonic episodes since the Archaean. However, detailed textural analysis of this accessory mineral has always been hampered by two-dimensional (2D) analytical limitations. With the advancements in X-ray nanotomography technology, it is now possible to non-destructively, yet digitally, cut, visualize, compare and quantify internal textures within zircons, their growth and zoning patterns and chemical distribution of trace elements in three dimensions (3D)...
March 16, 2018: Scientific Reports
Rami Darwazeh, Miao Wei, Jianjun Zhong, Zhaosi Zhang, Fajin Lv, Mazhar Darwazeh, Yi Guo, Yi Yan, Samer S Hoz, Xiaochuan Sun
OBJECTIVE: Little is known about the pathophysiological mechanisms of white matter injury after aneurysmal subarachnoid hemorrhage (aSAH). The purpose of this study is to investigate whether mammillothalamic tract (MTT) or corticospinal tract (CST) is more affected by aSAH in the same patients with good-outcome (Grade 5 on Glasgow Outcome Scale (GOS) at 3 months) using diffusion tensor imaging (DTI). METHODS: Between June 2013 to September 2016, 21 good-outcome patients with aSAH and 21 sex-and age-matched normal healthy control participants were recruited...
March 13, 2018: World Neurosurgery
Haotian Lin, Li Zhang, Duoru Lin, Wan Chen, Yi Zhu, Chuan Chen, Kevin C Chan, Yizhi Liu, Weirong Chen
BACKGROUND: Visual function and brain function decline concurrently with aging. Notably, cataract patients often present with accelerated age-related decreases in brain function, but the underlying mechanisms are still unclear. Optical structures of the anterior segment of the eyes, such as the lens and cornea, can be readily reconstructed to improve refraction and vision quality. However, the effects of visual restoration on human brain function and structure remain largely unexplored...
March 7, 2018: EBioMedicine
Tsutomu Nomura, Munetaka Ushio, Kenji Kondo, Shigeru Kikuchi
OBJECTIVE: The purpose of this research is to examine the changes in nasal airflow dynamics before and after the nasal perforation repair. METHODS: Three dimensional (3D) models of the nasal cavity before and after septal perforation repair was reconstructed using preoperative and postoperative computed tomography (CT) images of a patient. The numerical simulation was carried out using ANSYS CFX V15.0. Pre- and post-operative models were compared by their velocity, pressure (P), pressure gradient (PG), wall shear (WS), shear strain rate (SSR) and turbulence kinetic energy (TKE) in three plains...
March 13, 2018: Auris, Nasus, Larynx
René Ledesma-Alonso, Romeli Barbosa, Jaime Ortegón
The characterization and reconstruction of heterogeneous materials, such as porous media and electrode materials, involve the application of image processing methods to data acquired by scanning electron microscopy or other microscopy techniques. Among them, binarization and decimation are critical in order to compute the correlation functions that characterize the microstructure of the above-mentioned materials. In this study, we present a theoretical analysis of the effects of the image-size reduction, due to the progressive and sequential decimation of the original image...
February 2018: Physical Review. E
Idan Steinberg, Gil Tamir, Israel Gannot
Solid malignant tumors are one of the leading causes of death worldwide. Many times complete removal is not possible and alternative methods such as focused hyperthermia are used. Precise control of the hyperthermia process is imperative for the successful application of such treatment. To that end, this research presents a fast method that enables the estimation of deep tissue heat distribution by capturing and processing the transient temperature at the boundary based on a bio-heat transfer model. The theoretical model is rigorously developed and thoroughly validated by a series of experiments...
March 16, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Kurtis H Dekker, Rubin Hazarika, Matheus A Silveira, Kevin J Jordan
Optical cone beam computed tomography (CT) scanning of radiochromic gel dosimeters, using a CCD camera and a low stray light convergent source, provides fast, truly 3D radiation dosimetry with high accuracy. However, a key limiting factor in radiochromic gel dosimetry at large (⩾10 cm diameter) volumes is the initial attenuation of the dosimeters. It is not unusual to observe a 5-10×  difference in signal intensity through the dosimeter center versus through the surrounding medium in pre-irradiation images...
March 16, 2018: Physics in Medicine and Biology
Saikat Chowdhury, Noopur Sinha, Piyali Ganguli, Rupa Bhowmick, Vidhi Singh, Sutanu Nandi, Ram Rup Sarkar
BIOchemical PathwaY DataBase is developed as a manually curated, readily updatable, dynamic resource of human cell specific pathway information along with integrated computational platform to perform various pathway analyses. Presently, it comprises of 46 pathways, 3189 molecules, 5742 reactions and 6897 different types of diseases linked with pathway proteins, which are referred by 520 literatures and 17 other pathway databases. With its repertoire of biochemical pathway data, and computational tools for performing Topological, Logical and Dynamic analyses, BIOPYDB offers both the experimental and computational biologists to acquire a comprehensive understanding of signaling cascades in the cells...
March 16, 2018: Journal of Integrative Bioinformatics
Hsuan-Ming Huang, Chih-Chieh Liu, Meei-Ling Jan, Ming-Wei Lee
The Compton camera is an imaging device which has been proposed to detect prompt gammas (PGs) produced by proton-nuclear interactions within tissue during proton beam irradiation. Compton-based PG imaging has been developed to verify proton range because PG rays, particularly characteristic ones, have strong correlations with the distribution of the proton dose. However, accurate image reconstruction from characteristic PGs is challenging because the detector efficiency and resolution are generally low. Our previous study showed that point spread functions can be incorporated into the reconstruction process to improve image resolution...
March 16, 2018: Physics in Medicine and Biology
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