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Dual energy computed tomography

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https://www.readbyqxmd.com/read/30107255/differential-associations-between-appendicular-and-axial-marrow-adipose-tissue-with-bone-microarchitecture-in-adolescents-and-young-adults-with-obesity
#1
Vibha Singhal, Landy P Torre Flores, Fatima C Stanford, Alexander T Toth, Brian Carmine, Madhusmita Misra, Miriam A Bredella
Marrow adipose tissue (MAT) in humans is distributed differentially across age and skeletal site. We have shown impaired microarchitecture and reduced bone strength at appendicular sites in conditions associated with high MAT of the axial skeleton in adults (including conditions of over- and undernutrition). Data are lacking regarding differences in MAT content of the appendicular versus the axial skeleton, and its relationship with bone microarchitecture and strength. Furthermore, data are conspicuously lacking in adolescents, a time when hematopoietic marrow is progressively converted to fatty marrow...
August 11, 2018: Bone
https://www.readbyqxmd.com/read/30104921/bone-mineral-density-t-scores-derived-from-ct-attenuation-numbers-hounsfield-units-clinical-utility-and-correlation-with-dual-energy-x-ray-absorptiometry
#2
Nathan R Hendrickson, Perry J Pickhardt, Alejandro Munoz Del Rio, Humberto G Rosas, Paul A Anderson
Background: Clinical computed tomography (CT) studies performed for other indications can be used to opportunistically assess vertebral bone without additional radiation or cost. Reference values for young women are needed to evaluate diagnostic accuracy and track changes in CT bone mineral density values across the lifespan. The purpose of this study was to determine reference values for lumbar trabecular CT attenuation (Hounsfield units [HU]) and determine the diagnostic accuracy of HU T-scores (T-scoreHU ) for identifying individuals with osteoporosis...
2018: Iowa Orthopaedic Journal
https://www.readbyqxmd.com/read/30103370/the-small-animal-material-discrimination-study-based-on-equivalent-monochromatic-energy-projection-decomposition-method-with-dual-energy-ct-system
#3
Xiaochuan Wu, Peng He, Yi Zhang, Mianyi Chen, Biao Wei, Fenglin Liu, Kang An, Peng Feng
Material discrimination is an important application of dual-energy computed tomography (CT) techniques. Projection decomposition is a key problem for pre-reconstruction material discrimination. In this study, we focused on the pre-reconstruction space based on the photoelectric and Compton effect decomposition model to characterize different material components, and proposed an efficient method to calculate the projection decomposition coefficient. We converted the complex projection integral into a linear equation by calculating the equivalent monochromatic energy from the high and low energy spectrum...
August 6, 2018: Journal of X-ray Science and Technology
https://www.readbyqxmd.com/read/30102789/teriparatide-treatment-increases-mineral-content-and-volume-in-cortical-and-trabecular-bone-of-iliac-crest-a-comparison-of-infrared-imaging-with-x-ray-based-bone-assessment-techniques
#4
Paschalis Ep, Krege Jh, Gamsjaeger S, Eriksen Ef, Burr Db, Disch Dp, Stepan Jj, Fahrleitner-Pammer A, Klaushofer K, Marin F, Pavo I
Teriparatide increases bone mass primarily through remodeling of older or damaged bone and abundant replacement with new mineralizing bone. This post-hoc analysis investigated whether dual energy X-ray absorptiometric (DXA) areal bone mineral density (aBMD) measurement adequately reflects changes of mineral and organic matrix content in cortical and trabecular bone. Paired biopsies and aBMD measurements were obtained before and at end of 2-years of teriparatide treatment from postmenopausal women with osteoporosis who were either alendronate pre-treated (mean of 57...
August 13, 2018: Journal of Bone and Mineral Research: the Official Journal of the American Society for Bone and Mineral Research
https://www.readbyqxmd.com/read/30102636/a-novel-method-for-the-prediction-of-the-pedicle-screw-stability-regional-bone-mineral-density-around-the-screw
#5
Koji Ishikawa, Tomoaki Toyone, Toshiyuki Shirahata, Yoshifumi Kudo, Akira Matsuoka, Hiroshi Maruyama, Chikara Hayakawa, Soji Tani, Masaya Sekimizu, Koki Tsuchiya, Takeshi Eguro, Yusuke Oshita, Tomoyuki Ozawa, Yusuke Nakao, Shigeo Sano, Takashi Nagai, Koji Kanzaki, Katsunori Inagaki
STUDY DESIGN: Prospective feasibility study on consecutive patients. OBJECTIVE: The aim of this study was to investigate the ability of regional BMD around the pedicle screw to predict the screw fixation. SUMMARY OF BACKGROUND DATA: Pedicle screw fixation is the gold standard technique for spinal fusion. Despite the advantage of biomechanical stability, screw loosening is a common complication. In previous studies, pullout strength and screw insertional torque were correlated, and most importantly, affected by bone mineral density (BMD)...
August 10, 2018: Clinical Spine Surgery
https://www.readbyqxmd.com/read/30101756/coronary-artery-calcium-quantification-using-contrast-enhanced-dual-energy-computed-tomography-scans-in-comparison-with-unenhanced-single-energy-scans
#6
Qin Li, Benjamin P Berman, Tomoe Hagio, Marios A Gavrielides, Rongping Zeng, Berkman Sahiner, Qi Gong, Yuan Fang, Songtao Liu, Nicholas P Petrick
Extracting coronary artery calcium (CAC) scores from contrast-enhanced computed tomography (CT) images using dual-energy (DE) based material decomposition has been shown feasible, mainly through patient studies. However, the quantitative performance of such DE-based CAC scores, particularly per-stenosis, is underexamined due to lack of reference standard and repeated scans. In this work we conducted a comprehensive quantitative comparative analysis of CAC scores obtained with DE and compare to conventional unenhanced single-energy (SE) CT scans through phantom studies...
August 13, 2018: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/30100943/capabilities-of-the-monte-carlo-simulation-codes-for-modeling-of-a-small-animal-spect-camera
#7
Alireza Sadremomtaz, Zeinab Telikani
Purpose: This study aims to compare Monte Carlo-based codes' characteristics in the determination of the basic parameters of a high-resolution single photon emission computed tomography (HiReSPECT) scanner. Methods: The geometry of this dual-head gamma camera equipped with a pixelated CsI(Na) scintillator and lead hexagonal hole collimator were accurately described in the GEANT4 Application for the Tomographic Emission (GATE), Monte Carlo N-particle extended (MCNP-X), and simulation of imaging nuclear detectors (SIMIND) codes...
August 2018: Nuclear Medicine and Molecular Imaging
https://www.readbyqxmd.com/read/30098418/the-trabecular-bone-score-relationships-with-trabecular-and-cortical-microarchitecture-measured-by-hr-pqct-and-histomorphometry-in-patients-with-chronic-kidney-disease
#8
J Ramalho, I D B Marques, Didier Hans, David Dempster, Hua Zhou, Parth Patel, R M R Pereira, V Jorgetti, R M A Moyses, Thomas L Nickolas
The trabecular bone score (TBS) is a novel tool using grayscale variograms of the lumbar spine bone mineral density (BMD) to assess trabecular bone microarchitecture. Studies in patients with chronic kidney disease (CKD) suggest it may be helpful in assessing fracture risk. However, TBS has not been validated as a measure of trabecular architecture against transiliac bone biopsy with histomorphometry in CKD patients. We hypothesized that TBS would reflect trabecular architecture at the iliac crest in CKD patients...
August 8, 2018: Bone
https://www.readbyqxmd.com/read/30098038/towards-context-sensitive-ct-imaging-organ-specific-image-formation-for-single-sect-and-dual-energy-computed-tomography-dect
#9
Sabrina Dorn, Shuqing Chen, Stefan Sawall, Joscha Maier, Michael Knaup, Monika Uhrig, Heinz-Peter Schlemmer, Andreas Maier, Michael Lell, Marc Kachelrieß
PURPOSE: To establish a novel paradigm to facilitate radiologists' workow: combining mutually exclusive CT image properties that emerge from different reconstructions, display settings and organ-dependent spectral evaluation methods into a single context-sensitive imaging by exploiting prior anatomical information. METHODS: The CT dataset is segmented and classified into different organs, e.g. the liver, left and right kidney, spleen, aorta and left and right lung, as well as into the tissue types bone, fat, soft tissue and vessels using a cascaded 3D fully convolutional neural network (CNN) consisting of two successive 3D U-nets...
August 11, 2018: Medical Physics
https://www.readbyqxmd.com/read/30096063/interscanner-and-intrascanner-comparison-of-virtual-unenhanced-attenuation-values-derived-from-twin-beam-dual-energy-and-dual-source-dual-energy-computed-tomography
#10
Markus M Obmann, Vanessa Kelsch, Aurelio Cosentino, Verena Hofmann, Daniel T Boll, Matthias R Benz
OBJECTIVE: The aim of the current study was to evaluate the reliability and comparability of virtual unenhanced (VUE) attenuation values derived from scans of a single-source, dual-energy computed tomography using a split-filter (tbDECT) to a dual-source dual-energy CT (dsDECT). MATERIALS AND METHODS: In this retrospective study, comparisons for tbDECT and dsDECT were made within and between different dual-energy platforms. For the interscanner comparison, 126 patients were scanned with both scanners within a time interval of 224 ± 180 days; for the intrascanner comparison, another 90 patients were scanned twice with the same scanner within a time interval of 136 ± 140 days...
August 9, 2018: Investigative Radiology
https://www.readbyqxmd.com/read/30095624/improved-differentiation-between-high-and-low-grade-gliomas-by-combining-dual-energy-ct-analysis-and-perfusion-ct
#11
Yoko Kaichi, Fuminari Tatsugami, Yuko Nakamura, Yasutaka Baba, Makoto Iida, Toru Higaki, Masao Kiguchi, So Tsushima, Fumiyuki Yamasaki, Vishwa Jeet Amatya, Yukio Takeshima, Kaoru Kurisu, Kazuo Awai
The purpose of this study was to investigate the value of the cerebral blood volume (CBV) obtained with perfusion computed tomography (CT) and the electron density (ED) measured by dual-energy CT for differentiating high- from low-grade glioma (HGG, LGG).The CBV and ED were obtained in 9 LGG and 7 HGG patients. The CBV and ED of LGGs and HGGs were compared. Receiver operating characteristic (ROC) curves were generated for CBV, ED, and CBV plus ED. The correlation between CBV, ED, and the MIB-1 labeling index of the tumors was examined...
August 2018: Medicine (Baltimore)
https://www.readbyqxmd.com/read/30094537/locally-advanced-gastric-cancer-total-iodine-uptake-to-predict-the-response-of-primary-lesion-to-neoadjuvant-chemotherapy
#12
Xiaoyuan Gao, Yang Zhang, Fei Yuan, Bei Ding, Qianchen Ma, Wenjie Yang, Jing Yan, Lianjun Du, Baisong Wang, Fuhua Yan, Martin Sedlmair, Zilai Pan, Huan Zhang
PURPOSE: Pathologic response to neoadjuvant chemotherapy is a prognostic factor in many cancer types. However, the existing evaluative criteria are deficient. We sought to prospectively evaluate the total iodine uptake derived from dual-energy computed tomography (DECT) in predicting treatment efficacy and progression-free survival (PFS) time in gastric cancer after neoadjuvant chemotherapy. METHODS: From October 2012 to December 2015, 44 patients with locally advanced gastric cancer were examined with DECT 1 week before and three cycles after neoadjuvant chemotherapy...
August 9, 2018: Journal of Cancer Research and Clinical Oncology
https://www.readbyqxmd.com/read/30088275/comparative-performance-assessment-of-beam-hardening-correction-algorithms-applied-on-simulated-data-sets
#13
W Cao, T Sun, G Fardell, B Price, W Dewulf
Beam hardening artefacts deteriorate the reconstructed image quality in industrial computed tomography. The appearances of beam hardening artefacts can be cupping effects or streaks. They impair the image fidelity to the object being scanned. This work aims at comparing a variety of commonly used beam hardening correction algorithms in the context of industrial computed tomography metrology. We choose four beam hardening correction algorithms of different types for the comparison. They are a single-material linearization algorithm, a multimaterial linearization algorithm, a dual-energy algorithm and an iterative reconstruction algorithm...
August 8, 2018: Journal of Microscopy
https://www.readbyqxmd.com/read/30086870/update-on-bone-density-measurements-and-their-interpretation-in-children-and-adolescents
#14
REVIEW
Natascia Di Iorgi, Katia Maruca, Giuseppa Patti, Stefano Mora
Following the increased awareness about the central role of the pediatric age in building bone for life, clinicians face more than ever the necessity of assessing bone health in pediatric subjects at risk for early bone mass derangements or in healthy children, in order to optimize their bone mass accrual and prevent osteoporosis. Although the diagnosis of osteoporosis is not made solely upon bone mineral density measurements during growth, such determination can be very useful in the follow-up of pediatric patients with primary and secondary osteoporosis...
August 2018: Best Practice & Research. Clinical Endocrinology & Metabolism
https://www.readbyqxmd.com/read/30086561/-update-on-gout-and-calcium-pyrophosphate-deposition-cppd
#15
Monika Reuss-Borst, Anne-Kathrin Tausche
The metabolic diseases gout and calciumpyrophosphate deposition (CPPD) (formerly: chondrocalcinosis/pseudogout) are crystal arthropathies which are caused by crystals in synovial fluid and in the case of gout also in periarticular structures. Today, in particular gout is considered as an auto-inflammatory process since phagocytosis of monosodium urate crystals by monocytes/macrophages results in the activation of the innate immune system by activation of the NRLP3-Inflammasome and consecutive secretion of the key cytokine interleukin-1ß and other pro-inflammatory cytokines...
August 2018: Deutsche Medizinische Wochenschrift
https://www.readbyqxmd.com/read/30084035/state-of-the-art-imaging-for-the-evaluation-of-pulmonary-embolism
#16
REVIEW
Leonid Roshkovan, Harold Litt
PURPOSE OF REVIEW: CT angiography has become the gold standard for evaluation of suspected pulmonary embolism; however, continuous evolution in radiology has led to new imaging approaches that offer improved options for detection and characterization of pulmonary embolism while exposing patients to lower contrast and radiation dose. The purpose of this review is to summarize state of the art imaging approaches for the evaluation of pulmonary embolism, focusing on technical innovations in this field...
August 7, 2018: Current Treatment Options in Cardiovascular Medicine
https://www.readbyqxmd.com/read/30080234/critical-evaluation-of-muscle-mass-loss-as-a-prognostic-marker-of-morbidity-in-critically-ill-patients-and-methods-for-its-determination
#17
Vera Joskova, Anna Patkova, Eduard Havel, Simona Najpaverova, Daniela Uramova, Miroslav Kovarik, Zdenek Zadak, Miloslav Hronek
OBJECTIVE: Loss of muscle mass in critically ill patients is associated with serious consequences, such as prolonged mechanical ventilation, intensive care unit confinement, and higher mortality. Thus, monitoring muscle mass, and especially its decline, should provide a useful indicator of morbidity and mortality. Performing evaluations according only to body mass index is imperfect, therefore the aim of this article was to evaluate appropriate methods for muscle mass loss determination in ICU patients...
August 6, 2018: Journal of Rehabilitation Medicine
https://www.readbyqxmd.com/read/30076456/diagnostic-accuracy-of-third-generation-dual-source-dual-energy-ct-a-prospective-trial-and-protocol-for-clinical-implementation
#18
Tim Nestler, Kai Nestler, Andreas Neisius, Hendrik Isbarn, Christopher Netsch, Stephan Waldeck, Hans U Schmelz, Christian Ruf
PURPOSE: Uric acid (UA) calculi can be referred to chemolitholysis rather than invasive treatment. Dual-energy computed tomography (DECT) may be able to distinguish between UA and non-UA (NUA) calculi. The aim of this study was to evaluate the validity of third-generation DECT for the first time and to investigate whether combining DECT with clinical parameters can increase its predictive accuracy. MATERIALS AND METHODS: All patients who presented to our emergency department between January 2015 and March 2017 with urinary stones were prospectively included in this observational study and underwent DECT with subsequent interventional stone removal...
August 3, 2018: World Journal of Urology
https://www.readbyqxmd.com/read/30074599/multimodal-prussian-blue-analogs-as-contrast-agents-for-x-ray-computed-tomography
#19
Premrudee Promdet, Bárbara Rodríguez-García, Alexandria Henry, Cathie Nguyen, Thien Khuu, Jose-Ramon Galan-Mascaros, Karn Sorasaenee
Prussian blue analogs (PBAs) are versatile materials with a wide range of applications. Due to their tunability, intrinsic biocompatibility, as well as low toxicity, these nanoscale coordination polymers have been successfully studied as multimodal contrast agents for multiple imaging techniques. Herein, we report the expanded biomedical application of PBAs to X-ray computed tomography (CT). In our systematic study of the series A{MnII[FeIII(CN)6]} (A = K+, Rb+, Cs+), we showed that derivatives incorporating Rb+ and Cs+ ions in the tetrahedral sites of the parent face-centered cubic cyano-bridged networks exhibited substantially increased X-ray attenuation coefficients, thus yielding significant contrast compared to the clinically approved X-ray contrast agent iohexol at the same concentrations...
August 3, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/30072295/optimization-of-monoenergetic-extrapolations-in-dual-energy-ct-for-metal-artifact-reduction-in-different-body-regions-and-orthopedic-implants
#20
Lukas Horat, Mustafa Q Hamie, Florian A Huber, Roman Guggenberger
RATIONALE AND OBJECTIVES: To define an optimal monoenergetic extrapolation (ME) in dual-energy computed tomography (DECT) for metal artifact reduction (MAR) including different body regions and orthopedic implants. MATERIAL AND METHODS: DECT scans were acquired with dual-source CT (SOMATOM Force, Siemens, Germany) at tube voltage A 80-100 kV/B Sn150 kV from 39 patients (mean 54.1 ± 20.7 years, 23 male vs. 16 female) with orthopedic implants ranging from wires to joint implants...
July 30, 2018: Academic Radiology
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