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https://www.readbyqxmd.com/read/28651163/ex-vivo-assessment-of-valve-thickness-calcification-of-patients-with-calcific-aortic-stenosis-in-relation-to-in-vivo-clinical-outcomes
#1
Ching-Li Cheng, Hsiao-Huang Chang, Pei-Jung Huang, Wei-Chen Wang, Shan-Yang Lin
Calcific aortic stenosis (AS) plays a critical role in the risk of cardiovascular disease. This preliminary study examined the relationship between the ex vivo valve thickness/calcification and in vivo clinical outcomes of Chinese patients with calcific AS. Six Chinese patients (3 patients with tricuspid aortic valves (TAV)) and 3 patients with. bicuspid aortic valves (BAV) with calcific AS undergoing heart valve replacement were initially chosen for this study. In vivo medical imaging of these calcific AS patients was evaluated using computed tomography and echocardiography...
June 22, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28650890/solitary-choroidal-metastasis-from-lung-adenocarcinoma-on-fdg-pet-ct
#2
Zu-Gui Li
Solitary choroidal metastasis as an initial presentation of lung cancer is rare. A 67-year-old woman who initially presented with a 3-month history of blurred vision in the right eye was suggestive of choroidal melanoma on MRI. Preoperatively, a pulmonary mass was found on x-ray. She was referred for an FDG PET/CT imaging, which revealed a choroidal lesion with minimal FDG uptake in right eye and increased FDG activity in the known lung mass. A pathological diagnosis of metastatic lung adenocarcinoma was made after enucleation of the right eyeball...
June 24, 2017: Clinical Nuclear Medicine
https://www.readbyqxmd.com/read/28650806/3d-active-contour-segmentation-based-on-sparse-linear-combination-of-training-shapes-scots
#3
M Mehdi Farhangi, Hichem Frigui, Albert Seow, Amir A Amini
SCoTS captures a sparse representation of shapes in an input image through a linear span of previously delineated shapes in a training repository. The model updates shape prior over level set iterations and captures variabilities in shapes by a sparse combination of the training data. The level set evolution is therefore driven by a data term as well as a term capturing valid prior shapes. During evolution, the shape prior influence is adjusted based on shape reconstruction, with the assigned weight determined from the degree of sparsity of the representation...
June 26, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28650174/dissolution-processes-at-step-edges-of-calcite-in-water-investigated-by-high-speed-frequency-modulation-atomic-force-microscopy-and-simulation
#4
Kazuki Miyata, John Tracey, Keisuke Miyazawa, Ville Anton Haapasilta, Peter Spijker, Yuta Kawagoe, Adam S Foster, Katsuo Tsukamoto, Takeshi Fukuma
The microscopic understanding of the crystal growth and dissolution processes have been greatly advanced by the direct imaging of nanoscale step flows by atomic force microscopy (AFM), optical interferometry and x-ray microscopy. However, one of the most fundamental events that govern their kinetics, namely, atomistic events at the step edges have not been well understood. In this study, we have developed high-speed frequency modulation AFM (FM-AFM) and enabled true atomic-resolution imaging in liquid at ~1 s/frame, which is ~50 times faster than the conventional FM-AFM...
June 26, 2017: Nano Letters
https://www.readbyqxmd.com/read/28649157/use-of-patient-specific-3d-printed-neurovascular-phantoms-to-evaluate-the-clinical-utility-of-a-high-resolution-x-ray-imager
#5
S V Setlur Nagesh, M Russ, C N Ionita, D Bednarek, S Rudin
Modern 3D printing technology can fabricate vascular phantoms based on an actual human patient with a high degree of precision facilitating a realistic simulation environment for an intervention. We present two experimental setups using 3D printed patient-specific neurovasculature to simulate different disease anatomies. To simulate the human neurovasculature in the Circle of Willis, patient-based phantoms with aneurysms were 3D printed using a Objet Eden 260V printer. Anthropomorphic head phantoms and a human skull combined with acrylic plates simulated human head bone anatomy and x-ray attenuation...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28649021/k-edge-eliminated-material-decomposition-method-for-dual-energy-x-ray-ct
#6
Tiao Zhao, Liang Li, Zhiqiang Chen
In medical dual-energy CT, projection-domain decomposition is typically used to process the acquired two projection datasets. However, when a high atomic-number contrast-agent is introduced, its K-edge discontinuity challenges this method. In this work, we take advantage of the fact that the contrast agent and its solvent are known in advance and propose to first decompose the attenuation coefficient functions of the contrast agent and its solvent to estimate the attenuation contribution of the K-shell photoelectric...
June 17, 2017: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/28648432/importance-of-the-heart-borders-as-a-fluoroscopic-clue-for-cardiac-tamponade
#7
Halil Lutfi Kisacik, Sefa Unal, Burak Acar, Hande Cetin, Ozcan Ozeke
Every catheter laboratory is equipped with an X-ray system designed to provide fluoroscopic imaging of the heart. Although cardiac catheters are well visualized in all X-ray imaging, the soft tissue of myocardium is not. Therefore the imaging of the cardiac chambers is indirect through relation to the cardiac silhouette. However, fluoroscopy can be used to detect complications from the invasive procedures in the cardiac catheterization laboratory, such as cardiac tamponade where the excursion of the cardiac silhouette decreases, and visceral and parietal pericardium are seen separated by the blood of accumulation in the pericardial cavity...
May 2017: Indian Heart Journal
https://www.readbyqxmd.com/read/28647400/intraoperative-registered-ultrasound-and-fluoroscopy-iruf-for-dose-calculation-during-prostate-brachytherapy-improved-accuracy-compared-to-standard-ultrasound-based-dosimetry
#8
Junghoon Lee, Omar Y Mian, Yi Le, Hee Joon Bae, E Clif Burdette, Theodore L DeWeese, Jerry L Prince, Daniel Y Song
BACKGROUND AND PURPOSE: Intraoperative transrectal ultrasound dosimetry during low-dose-rate prostate brachytherapy is imprecise due to sonographic distortion caused by seed echoes and needle tracks that obscure seed positions or create false signals as well as traumatic edema. Here we report the results of a pilot study comparing a combined ultrasound and fluoroscopy-based seed localization method (iRUF) to standard ultrasound-based dosimetry (USD). MATERIAL AND METHODS: Eighty patients undergoing permanent Pd-103 seed implantation for prostate cancer were prospectively enrolled...
June 21, 2017: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/28645458/pulmonary-3-he-magnetic-resonance-imaging-biomarkers-of-regional-airspace-enlargement-in-alpha-1-antitrypsin-deficiency
#9
Eric Lessard, Heather M Young, Anurag Bhalla, Damien Pike, Khadija Sheikh, David G McCormack, Alexei Ouriadov, Grace Parraga
RATIONALE AND OBJECTIVES: Thoracic x-ray computed tomography (CT) and hyperpolarized (3)He magnetic resonance imaging (MRI) provide quantitative measurements of airspace enlargement in patients with emphysema. For patients with panlobular emphysema due to alpha-1 antitrypsin deficiency (AATD), sensitive biomarkers of disease progression and response to therapy have been difficult to develop and exploit, especially those biomarkers that correlate with outcomes like quality of life. Here, our objective was to generate and compare CT and diffusion-weighted inhaled-gas MRI measurements of emphysema including apparent diffusion coefficient (ADC) and MRI-derived mean linear intercept (Lm) in patients with AATD, chronic obstructive pulmonary disease (COPD) ex-smokers, and elderly never-smokers...
June 20, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28645457/diagnostic-medical-imaging-in-pediatric-patients-and-subsequent-cancer-risk
#10
REVIEW
David J Mulvihill, Sachin Jhawar, John B Kostis, Sharad Goyal
The use of diagnostic medical imaging is becoming increasingly more commonplace in the pediatric setting. However, many medical imaging modalities expose pediatric patients to ionizing radiation, which has been shown to increase the risk of cancer development in later life. This review article provides a comprehensive overview of the available data regarding the risk of cancer development following exposure to ionizing radiation from diagnostic medical imaging. Attention is paid to modalities such as computed tomography scans and fluoroscopic procedures that can expose children to radiation doses orders of magnitude higher than standard diagnostic x-rays...
June 20, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28644800/online-combination-of-epid-cherenkov-imaging-for-3d-dosimetry-in-a-liquid-phantom
#11
Petr Bruza, Jacqueline M Andreozzi, David J Gladstone, Lesley A Jarvis, Joerg Rottmann, Brian W Pogue
Online acquisition of Cherenkov and portal imaging data was combined with a reconstruction scheme called EC3D, providing a full 3D dosimetry of megavoltage X-ray beams in a water tank. The methodology was demonstrated and quantified in a single static beam. Furthermore, the dynamics and visualization of the 3D dose reconstruction were demonstrated with a volumetric modulated arc therapy (VMAT) plan for TG-119 C-Shape geometry. The developed algorithm combines depth dose information, provided by Cherenkov images, with the lateral dose distribution, provided by the electronic portal imaging device (EPID)...
June 20, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28643923/micro-anatomical-responses-in-periodontal-complexes-of-mice-to-calibrated-orthodontic-forces-on-the-crown
#12
A Pal, L Chen, L Yang, F Yang, B Meng, A H Jheon, S P Ho
OBJECTIVE: Correlating mechanical forces with quantifiable physical changes in the dentoalveolar complex. SETTING AND SAMPLE POPULATION: Male 6-week C57BL/6 mice (N=3), micro X-ray-computed tomography; post-analysis software to extract physical changes in periodontal ligament (PDL)-space. MATERIALS AND METHODS: Silicone-elastic bands were placed between maxillary molars for 1 week, with the contralateral side as internal control. Average displacements between crowns and roots, and changes in PDL-spaces were evaluated by registering X-ray tomograms of experimental and control hemi-maxillae...
June 2017: Orthodontics & Craniofacial Research
https://www.readbyqxmd.com/read/28642964/metastasis-of-breast-cancer-cells-to-the-bone-lung-and-lymph-nodes-promotes-resistance-to-ionizing-radiation
#13
Takamitsu Hara, Manabu Iwadate, Kazunoshin Tachibana, Satoshi Waguri, Seiichi Takenoshita, Nobuyuki Hamada
BACKGROUND: Metastasis represents the leading cause of breast cancer deaths, necessitating strategies for its treatment. Although radiotherapy is employed for both primary and metastatic breast cancers, the difference in their ionizing radiation response remains incompletely understood. This study is the first to compare the radioresponse of a breast cancer cell line with its metastatic variants and report that such metastatic variants are more radioresistant. MATERIALS AND METHODS: A luciferase expressing cell line was established from human basal-like breast adenocarcinoma MDA-MB-231 and underwent in vivo selections, whereby a cycle of inoculations into the left cardiac ventricle or the mammary fat pad of athymic nude mice, isolation of metastases to the bone, lung and lymph nodes visualized with bioluminescence imaging, and expansion of obtained cells was repeated twice or three times...
June 22, 2017: Strahlentherapie und Onkologie: Organ der Deutschen Röntgengesellschaft ... [et Al]
https://www.readbyqxmd.com/read/28642718/irinotecan-induced-gastrointestinal-dysfunction-is-associated-with-enteric-neuropathy-but-increased-numbers-of-cholinergic-myenteric-neurons
#14
Rachel M McQuade, Vanesa Stojanovska, Elizabeth L Donald, Ahmed A Rahman, Dean G Campelj, Raquel Abalo, Emma Rybalka, Joel C Bornstein, Kulmira Nurgali
Gastrointestinal dysfunction is a common side-effect of chemotherapy leading to dose reductions and treatment delays. These side-effects may persist up to 10 years post-treatment. A topoisomerase I inhibitor, irinotecan (IRI), commonly used for the treatment of colorectal cancer, is associated with severe acute and delayed-onset diarrhea. The long-term effects of IRI may be due to damage to enteric neurons innervating the gastrointestinal tract and controlling its functions. Balb/c mice received intraperitoneal injections of IRI (30 mg/kg(-1)) 3 times a week for 14 days, sham-treated mice received sterile water (vehicle) injections...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28641250/deep-convolutional-neural-network-for-inverse-problems-in-imaging
#15
Kyong Hwan Jin, Michael T McCann, Emmanuel Froustey, Michael Unser
In this paper, we propose a novel deep convolutional neural network (CNN)-based algorithm for solving ill-posed inverse problems. Regularized iterative algorithms have emerged as the standard approach to ill-posed inverse problems in the past few decades. These methods produce excellent results, but can be challenging to deploy in practice due to factors including the high computational cost of the forward and adjoint operators and the difficulty of hyper parameter selection. The starting point of our work is the observation that unrolled iterative methods have the form of a CNN (filtering followed by point-wise nonlinearity) when the normal operator ( H*H where H* is the adjoint of the forward imaging operator, H ) of the forward model is a convolution...
June 15, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28641005/electron-crystallography-reveals-atomic-structures-of-metal-organic-nanoplates-with-m12-%C3%AE-3-o-8-%C3%AE-3-oh-8-%C3%AE-2-oh-6-m-zr-hf-secondary-building-units
#16
Ruihan Dai, Fei Peng, Pengfei Ji, Kuangda Lu, Cheng Wang, Junliang Sun, Wenbin Lin
Nanoscale metal-organic frameworks (nMOFs) have shown tremendous potential in cancer therapy and biomedical imaging. However, their small dimensions present a significant challenge in structure determination by single-crystal X-ray crystallography. We report here the structural determination of nMOFs by rotation electron diffraction (RED). Two isostructural Zr- and Hf-based nMOFs with linear biphenyldicarboxylate (BPDC) or bipyridinedicarboxylate (BPYDC) linkers are stable under intense electron beams to allow the collection of high-quality RED data, which reveal a MOF structure with M12(μ3-O)8(μ3-OH)8(μ2-OH)6 (M = Zr, Hf) secondary building units (SBUs)...
June 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28640950/development-of-a-monte-carlo-multiple-source-model-for-inclusion-in-a-dose-calculation-auditing-tool
#17
Austin M Faught, Scott E Davidson, Jonas Fontenot, Stephen F Kry, Carol Etzel, Geoffrey S Ibbott, David S Followill
PURPOSE: The Imaging and Radiation Oncology Core Houston (IROC-H) (formerly the Radiological Physics Center) has reported varying levels of agreement in their anthropomorphic phantom audits. There is reason to believe one source of error in this observed disagreement is the accuracy of the dose calculation algorithms and heterogeneity corrections used. To audit this component of the radiotherapy treatment process an independent dose calculation tool is needed. METHODS: Monte Carlo multiple source models for Elekta 6MV and 10MV therapeutic x-ray beams were commissioned based on measurement of central axis depth dose data for a 10 x 10 cm(2) field size and dose profiles for a 40 x 40 cm(2) field size...
June 22, 2017: Medical Physics
https://www.readbyqxmd.com/read/28640302/influence-of-substituents-on-dna-and-protein-binding-of-cyclometalated-ir-iii-complexes-and-anticancer-activity
#18
Sujay Mukhopadhyay, Roop Shikha Singh, Rajendra Prasad Paitandi, Gunjan Sharma, Biplob Koch, Daya Shankar Pandey
Synthesis of terpyridyl based ligands 3-([2,2':6',2''-terpyridin]-4'-yl)-7-methoxy-2-(methylthio)-quinolone, (L1); 3-([2,2':6',2''-terpyridin]-4'-yl)-6-methoxyquinolin-2(1H)-one, (L2); 3-([2,2'-:6',2''-terpyridin]-4'-yl)-6-methylquinolin-2(1H)-one (L3) and cyclometalated iridium(iii) complexes [[Ir(ppy)2L1](+)PF6(-) (1), [Ir(ppy)2L2](+)PF6(-) (2), [Ir(ppy)2L3](+)PF6(-) (3) (2-phenylpyridine = Hppy)] involving these ligands has been described. The ligands L1-L3 and complexes 1-3 have been thoroughly characterized by elemental analyses, spectral studies (IR, (1)H, (13)C NMR, UV/vis and fluorescence) ESI-MS, and the structure of 3 has been unambiguously authenticated by single crystal X-ray analyses...
June 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28640112/cement-leakage-in-osteoporotic-vertebral-compression-fractures-with-cortical-defect-using-high-viscosity-bone-cement-during-unilateral-percutaneous-kyphoplasty-surgery
#19
Tie Liu, Zhe Li, Qingjun Su, Yong Hai
The purpose of this study was to investigate cement leakage (CL) in osteoporotic vertebral compression fractures (OVCFs) with cortical defect using high-viscosity bone cement during unilateral percutaneous kyphoplasty (PKP) surgery.This study included a series of 77 patients (23 males, 54 females) with single level osteoporotic vertebral body fracture (OVCF) who underwent unilateral PKP in our hospital. Preoperative x-ray, computed tomography (CT) scan, and 3-dimensional reconstructions were studied. During the PKP procedure, needle was carefully put to avoid too near to the cortical defect according to CT image...
June 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28639400/motion-estimation-for-cardiac-functional-analysis-using-two-x-ray-computed-tomography-scans
#20
George S K Fung, Luisa Ciuffo, Hiroshi Ashikaga, Katsuyuki Taguchi
PURPOSE: This work concerns computed tomography (CT)-based cardiac functional analysis (CFA) with a reduced radiation dose. As CT-CFA requires images over the entire heartbeat, the scans are often performed at 10-20% of the tube current settings that are typically used for coronary CT angiography. A large image noise then degrades the accuracy of motion estimation. Moreover, even if the scan was performed during the sinus rhythm, the cardiac motion observed in CT images may not be cyclic with patients with atrial fibrillation...
June 22, 2017: Medical Physics
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