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Dual energy CT

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https://www.readbyqxmd.com/read/29333113/grating-oriented-line-wise-filtration-golf-for-dual-energy-x-ray-ct
#1
Yan Xi, Wenxiang Cong, Daniel Harrison, Ge Wang
In medical X-ray Computed Tomography (CT), the use of two distinct X-ray source spectra (energies) allows dose-reduction and material discrimination relative to that achieved with only one source spectrum. Existing dual-energy CT methods include source kVp-switching, double-layer detection, dual-source gantry, and two-pass scanning. Each method suffers either from strong spectral correlation or patient-motion artifacts. To simultaneously address these problems, we propose to improve CT data acquisition with the Grating Oriented Line-wise Filtration (GOLF) method, a novel X-ray filter that is placed between the source and patient...
December 2017: Sensing and Imaging
https://www.readbyqxmd.com/read/29331301/marrow-adipose-tissue-imaging-in-humans
#2
Vibha Singhal, Miriam A Bredella
Bone strength is affected not only by bone mineral density (BMD) and bone microarchitecture but also its microenvironment. Recent studies have focused on the role of marrow adipose tissue (MAT) in the pathogenesis of bone loss. Osteoblasts and adipocytes arise from a common mesenchymal stem cell within bone marrow and many osteoporotic states, including aging, medication use, immobility, over - and undernutrition are associated with increased marrow adiposity. Advancements in imaging technology allow the non-invasive quantification of MAT...
January 10, 2018: Bone
https://www.readbyqxmd.com/read/29329150/comparison-of-iodine-density-measurement-among-dual-energy-computed-tomography-scanners-from-3-vendors
#3
Hyungjin Kim, Jin Mo Goo, Chang Kyung Kang, Kum Ju Chae, Chang Min Park
OBJECTIVES: The aims of this study were to analyze the effect of dual-energy computed tomography (DECT) scanners and fluid characteristics on iodine quantification and to calculate the measurement variability range induced by those variables. METHODS: We performed an experimental phantom study with 4 mediastinal iodine phantoms. Each phantom contained 6 tubes of different iodine concentrations (0, 1.0, 2.5, 5.0, 10.0, and 20.0 mg/mL) diluted in a specific solvent, which was water, 10% amino acid solution, 20% lipid emulsion, or 18% calcium solution, respectively...
January 12, 2018: Investigative Radiology
https://www.readbyqxmd.com/read/29328082/linear-iterative-near-field-phase-retrieval-lipr-for-dual-energy-x-ray-imaging-and-material-discrimination
#4
Heyang Thomas Li, Andrew M Kingston, Glenn R Myers, Levi Beeching, Adrian P Sheppard
Near-field x-ray refraction (phase) contrast is unavoidable in many lab-based micro-CT imaging systems. Quantitative analysis of x-ray refraction (a.k.a. phase retrieval) is in general an under-constrained problem. Regularizing assumptions may not hold true for interesting samples; popular single-material methods are inappropriate for heterogeneous samples, leading to undesired blurring and/or over-sharpening. In this paper, we constrain and solve the phase-retrieval problem for heterogeneous objects, using the Alvarez-Macovski model for x-ray attenuation...
January 1, 2018: Journal of the Optical Society of America. A, Optics, Image Science, and Vision
https://www.readbyqxmd.com/read/29325542/visceral-adipose-tissue-and-carotid-intima-media-thickness-in-hiv-infected-patients-undergoing-cart-a-prospective-cohort-study
#5
Maria Teresa Beires, André Silva-Pinto, Ana Cristina Santos, António José Madureira, Jorge Pereira, Davide Carvalho, António Sarmento, Paula Freitas
BACKGROUND: Combined antiretroviral therapy (cART) in HIV-infected patients has been associated with lipodystrophy, metabolic abnormalities, and an increased risk of cardiovascular disease. Ultrasound measures of carotid artery intima-media thickness (cIMT) have been used as a valid measure of subclinical atherosclerosis and as a tool to predict the risk of cardiovascular events. Our aim was to evaluate the progression of cIMT in HIV-infected patients subjected to cART, with and without lipodystrophy, over a one-year period...
January 11, 2018: BMC Infectious Diseases
https://www.readbyqxmd.com/read/29320323/multimodality-imaging-including-dual-energy-ct-in-the-evaluation-of-gallbladder-disease
#6
Lisa Ratanaprasatporn, Jennifer W Uyeda, Jeremy R Wortman, Ian Richardson, Aaron D Sodickson
Imaging of the gallbladder has a key role in the examination of patients with abdominal pain-especially pain localized to the right upper quadrant. Pathologic conditions that affect the gallbladder include cholelithiasis and associated complications such as acute and chronic cholecystitis, choledocholithiasis, gallstone pancreatitis, and cancer. Modalities used to image the gallbladder include ultrasonography (US), computed tomography (CT), magnetic resonance (MR) imaging, and nuclear scintigraphy. US is the primary imaging modality used to evaluate entities suspected of being gallbladder disease, as it is both sensitive and specific for demonstrating gallstones, biliary duct dilatation, and inflammatory features...
January 2018: Radiographics: a Review Publication of the Radiological Society of North America, Inc
https://www.readbyqxmd.com/read/29312701/analysis-of-pulmonary-pure-ground-glass-nodule-in-enhanced-dual-energy-ct-imaging-for-predicting-invasive-adenocarcinoma-comparing-with-conventional-thin-section-ct-imaging
#7
Ying Zhang, Jian Tang, Jianrong Xu, Jiejun Cheng, Huawei Wu
Background: To investigate the value of dual energy computed tomography (DECT) parameters (including iodine concentration and monochromatic CT numbers) for predicting pure ground-glass nodules (pGGNs) of invasive adenocarcinoma (IA). Methods: A total of 55 resected pGGNs evaluated with both unenhanced thin-section CT (TSCT) and enhanced DECT scans were included. Correlations between histopathology [adenocarcinoma in situ (AIS), minimally IA (MIA), and IA] and CT scan characteristics were examined...
December 2017: Journal of Thoracic Disease
https://www.readbyqxmd.com/read/29279149/noise-characteristics-of-virtual-monoenergetic-images-from-a-novel-detector-based-spectral-ct-scanner
#8
Kevin Kalisz, Negin Rassouli, Amar Dhanantwari, David Jordan, Prabhakar Rajiah
AIM: To evaluate the noise characteristics of virtual monoenergetic images (VMI) obtained from a recently introduced dual-layer detector-based spectral CT (SDCT), both in a phantom and patients. MATERIALS AND METHODS: A cylindrical Catphan® 600 phantom (The Phantom Library, Salem NY, USA) was scanned using the SDCT. Image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were measured in VMI from 40 to 200keV as well as conventional 120 kVp images...
January 2018: European Journal of Radiology
https://www.readbyqxmd.com/read/29277840/investigating-comparability-of-quantitative-computed-tomography-with-dual-energy-x-ray-absorptiometry-in-assessing-bone-mineral-density-of-patients-with-chronic-spinal-cord-injury
#9
Hamid Reza Haghighat Khah, Nahid Moradi, Taher Taheri, Morteza Sanei Taheri, Seyed Mansoor Rayegani
STUDY DESIGN: Psychometric study using retrospectively collected data. OBJECTIVES: We investigated the comparability of quantitative computed tomography (qCT) in assessing bone mineral density (BMD) with dual energy X-ray absorptiometry (DXA). We evaluated how well previously suggested normal values for spinal Hounsfield units (HU) correlated with routine DXA results in patients with chronic spinal cord injury (SCI). Furthermore, we investigated inter/intra-observer reliability of measuring HU in the spine...
December 26, 2017: Spinal Cord
https://www.readbyqxmd.com/read/29277821/iodine-content-analysis-using-dual-energy-computed-tomography-as-a-biomarker-of-transitional-cell-carcinoma-an-experience-with-separation-of-the-clotted-blood-and-tumorous-tissue
#10
Hynek Mirka, Jan Baxa, Milan Hora, Ondrej Hes, Ondrej Topolcan, Jiri Ferda
BACKGROUND/AIM: The aim of this study was to evaluate the possibility to discriminate the blood clot from tumorous tissue in the assessment of transitional cell carcinoma (TCC), when CT data are used only from single-phase dual-energy CT (DECT). MATERIALS AND METHODS: A total of 18 patients were included into the retrospective analysis of the prospectively collected data (the average age was 67.3 years, range=62-79 years, 12 males, 6 females). DECT was performed in all patients after intravenous administration of the iodinated contrast material...
January 2018: Anticancer Research
https://www.readbyqxmd.com/read/29276564/dual-energy-ct-differentiates-contrast-staining-from-hemorrhagic-conversion-of-ischemic-stroke
#11
Derek R Johnson, Norbert G Campeau
No abstract text is available yet for this article.
January 2018: Neurohospitalist
https://www.readbyqxmd.com/read/29275940/how-well-does-dual-energy-ct-with-fast-kilovoltage-switching-quantify-ct-number-and-iodine-and-calcium-concentrations
#12
Shingo Ohira, Tsukasa Karino, Yoshihiro Ueda, Yuya Nitta, Naoyuki Kanayama, Masayoshi Miyazaki, Masahiko Koizumi, Teruki Teshima
RATIONALE AND OBJECTIVES: Because it is imperative for understanding the performance of dual-energy computed tomography scanner to determine clinical diagnosis, we aimed to assess the accuracy of quantitative measurements using dual-energy computed tomography with fast kilovoltage switching. MATERIALS AND METHODS: Quantitative measurements were performed for 16 reference materials (physical density, 0.965-1.550 g/cm3; diameter of rod, 2.0-28.5 mm; iodine concentration, 2-15 mg/mL; and calcium concentration, 50-300 mg/mL) with varying scanning settings, and the measured values were compared to their theoretical values...
December 21, 2017: Academic Radiology
https://www.readbyqxmd.com/read/29261468/can-dual-energy-ct-challenge-mr-imaging-in-the-diagnosis-of-focal-infiltrative-bone-marrow-lesions
#13
William E Palmer, F Joseph Simeone
No abstract text is available yet for this article.
January 2018: Radiology
https://www.readbyqxmd.com/read/29261337/current-and-emerging-imaging-techniques-in-the-diagnosis-and-assessment-of-pulmonary-hypertension
#14
Christopher S Johns, Jim M Wild, Smitha Rajaram, Andy J Swift, David G Kiely
Pulmonary hypertension (PH) is a challenging condition to diagnose and treat. Over the last two decades, there have been significant advances in therapeutic approaches and imaging technologies. Current guidelines emphasize the importance of cardiac catheterization; however, the increasing availability of non-invasive imaging has the potential to improve diagnostic rates, whilst providing additional information on patient phenotypes. Areas covered: This review discusses the role of imaging in the diagnosis, prognostic assessment and follow-up of patients with PH...
December 20, 2017: Expert Review of Respiratory Medicine
https://www.readbyqxmd.com/read/29260727/dosimetric-impact-of-dual-energy-ct-tissue-segmentation-for-low-energy-prostate-brachytherapy-a-monte-carlo-study
#15
Charlotte Remy, Arthur Lalonde, Dominic Béliveau-Nadeau, Jean-Francois Carrier, Hugo Bouchard
{\color{red}The purpose of this study is} to evaluate the impact of a novel tissue characterization method using dual-energy over single-energy computed tomography (DECT and SECT) on Monte Carlo (MC) dose calculations for low-dose rate (LDR) prostate brachytherapy performed in a patient like geometry. A virtual patient geometry is created using contours from a real patient pelvis CT scan, where known elemental compositions and varying densities are overwritten in each voxel. A second phantom is made with additional calcifications...
December 20, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29249450/perfusion-defects-in-pulmonary-perfusion-iodine-maps-causes-and-semiology
#16
A Bustos Fiore, M González Vázquez, C Trinidad López, D Mera Fernández, M Costas Álvarez
OBJECTIVE: to describe the usefulness of dual-energy CT for obtaining pulmonary perfusion maps to provide morphological and functional information in patients with pulmonary embolisms. To review the semiology of perfusion defects due to pulmonary embolism so they can be differentiated from perfusion defects due to other causes: alterations outside the range used in the iodine map caused by other diseases of the lung parenchyma or artifacts. CONCLUSION: CT angiography of the pulmonary arteries is the technique of choice for the diagnosis of pulmonary embolisms...
December 14, 2017: Radiología
https://www.readbyqxmd.com/read/29242134/non-contrast-estimation-of-diffuse-myocardial-fibrosis-with-dual-energy-ct-a-phantom-study
#17
Vidhya Kumar, Kevin E McElhanon, James K Min, Xin He, Zhaobin Xu, Eric X Beck, Orlando P Simonetti, Noah Weisleder, Subha V Raman
BACKGROUND: Estimation of diffuse myocardial fibrosis, substrate for adverse events such as heart failure and arrhythmias in patients with various cardiac disorders, is presently done by histopathology or cardiac magnetic resonance. We sought to develop a non-contrast method to estimate the amount of diffuse myocardial fibrosis leveraging dual energy computed tomography (DECT) in phantoms and a suitable small animal model. METHODS AND RESULTS: Phantoms consisted of homogenized bovine myocardium with varying amounts of Type 1 collagen...
December 5, 2017: Journal of Cardiovascular Computed Tomography
https://www.readbyqxmd.com/read/29241277/dual-energy-computed-tomography-in-musculoskeletal-imaging-with-focus-on-fragility-fractures-of-the-pelvis
#18
Carsten Hackenbroch, Hans-Joachim Riesner, Patricia Lang, Fabian Stuby, Meinrad Beer, Benedikt Friemert, Hans-Georg Palm
Dual energy computed tomography (DECT) is a constantly evolving technology, which opens up new diagnostic possibilities. It is particularly valuable for musculoskeletal (MSK) imaging. Due to the lack of recognition and availability of dual energy scanners, routine use is only established in a few centres. The intention of this review is to show the possibilities and fields of applications of the DECT in MSK imaging, as well as to describe technical principles and typical indications. We mainly focus on the use of DECT in the context of fragility fractures of the pelvis...
December 2017: Zeitschrift Für Orthopädie und Unfallchirurgie
https://www.readbyqxmd.com/read/29239855/experimental-verification-of-stopping-power-prediction-from-single-and-dual-energy-computed-tomography-in-biological-tissues
#19
Christian Möhler, Tom Russ, Patrick Wohlfahrt, Alina Elter, Armin Runz, Christian Richter, Steffen Greilich
An experimental setup for consecutive measurement of ion and x-ray absorption in tissue or other materials is introduced. With this setup using a 3D-printed sample container, the reference stopping-power ratio (SPR) of materials can be measured with an uncertainty of below 0.1%. A total of 65 porcine and bovine tissue samples were prepared for measurement, comprising five samples each of 13 tissue types representing about 80% of the total body mass (three different muscle and fatty tissues, liver, kidney, brain, heart, blood, lung and bone)...
December 14, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/29234002/dual-energy-micro-ct-for-quantifying-the-time-course-and-staining-characteristics-of-ex-vivo-animal-organs-treated-with-iodine-and-gadolinium-based-contrast-agents
#20
Juliana Martins de Souza E Silva, Julian Utsch, Melanie A Kimm, Sebastian Allner, Michael F Epple, Klaus Achterhold, Franz Pfeiffer
Chemical staining of soft-tissues can be used as a strategy to increase their low inherent contrast in X-ray absorption micro-computed tomography (micro-CT), allowing to obtain fast three-dimensional structural information of animal organs. Though some staining agents are commonly used in this context, little is known about the staining agents' ability to stain specific types of tissues; the times necessary to provide a sufficient contrast; and the effect of staining solution in distorting the tissue. Here we contribute to studies of animal organs (mouse heart and lungs) using staining combined with dual-energy micro-CT (DECT)...
December 12, 2017: Scientific Reports
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