keyword
MENU ▼
Read by QxMD icon Read
search

Dynamic contrast imaging

keyword
https://www.readbyqxmd.com/read/28644152/incorporating-hypr-de-noising-within-iterative-pet-reconstruction-hypr-osem
#1
Ju-Chieh Kevin Cheng, Julian C Matthews, Vesna Sossi, Jose Anton-Rodriguez, Andre Salomon, Ronald Boellaard
HighlY constrained back-PRojection (HYPR) is a post-processing de-noising technique originally developed for time-resolved Magnetic Resonance Imaging. It has been recently applied to dynamic imaging for Positron Emission Tomography (PET) and shown promising results. In this work, we have developed an iterative reconstruction algorithm (HYPR-OSEM) which improves the signal-to-noise ratio (SNR) in static imaging (i.e. single frame reconstruction) by incorporating HYPR de-noising directly within the ordered subsets expectation maximization (OSEM) algorithm...
June 23, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28644110/detailed-magnetic-resonance-imaging-features-of-a-case-series-of-primary-gliosarcoma
#2
Luísa Sampaio, Paulo Linhares, José Fonseca
Objective We aimed to characterise the magnetic resonance imaging (MRI) features of a case series of primary gliosarcoma, with the inclusion of diffusion-weighted imaging and perfusion imaging with dynamic susceptibility contrast MRI. Materials and methods We conducted a retrospective study of cases of primary gliosarcoma from the Pathology Department database from January 2006 to December 2014. Clinical and demographic data were obtained. Two neuroradiologists, blinded to diagnosis, assessed tumour location, signal intensity in T1 and T2-weighted images, pattern of enhancement, diffusion-weighted imaging and dynamic susceptibility contrast MRI studies on preoperative MRI...
January 1, 2017: Neuroradiology Journal
https://www.readbyqxmd.com/read/28643545/application-of-intravoxel-incoherent-motion-ivim-magnetic-resonance-imaging-in-the-evaluation-of-primitive-brain-tumours
#3
A Catanese, F Malacario, L Cirillo, F Toni, C Zenesini, D Casolino, A Bacci, R Agati
Intravoxel incoherent motion is a potential non-invasive diagnostic tool in brain tumours, without any clear guidelines for its evaluation yet. In our study, we compare intravoxel incoherent motion with dynamic susceptibility contrast magnetic resonance imaging in the quantification of tumour tissue blood perfusion in 28 patients affected by brain tumours, highlighting the issues encountered during the acquisition set-up and post-processing steps. Intravoxel incoherent motion is a new imaging tool and an alternative technique to dynamic susceptibility contrast-magnetic resonance imaging which is of considerable interest at present...
January 1, 2017: Neuroradiology Journal
https://www.readbyqxmd.com/read/28643383/multiecho-pseudo-golden-angle-stack-of-stars-thermometry-with-high-spatial-and-temporal-resolution-using-k-space-weighted-image-contrast
#4
Bryant T Svedin, Allison Payne, Bradley D Bolster, Dennis L Parker
PURPOSE: Implement and evaluate a 3D MRI method to measure temperature changes with high spatial and temporal resolution and large field of view. METHODS: A multiecho pseudo-golden angle stack-of-stars (SOS) sequence with k-space weighted image contrast (KWIC) reconstruction was implemented to simultaneously measure multiple quantities, including temperature, initial signal magnitude M(0), transverse relaxation time ( T2*), and water/fat images. Respiration artifacts were corrected using self-navigation...
June 22, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28643359/an-open-8-channel-parallel-transmission-coil-for-static-and-dynamic-7t-mri-of-the-knee-and-ankle-joints-at-multiple-postures
#5
Jin Jin, Ewald Weber, Aurelien Destruel, Kieran O'Brien, Bassem Henin, Craig Engstrom, Stuart Crozier
PURPOSE: We present the initial in vivo imaging results of an open architecture eight-channel parallel transmission (pTx) transceive radiofrequency (RF) coil array that was designed and constructed for static and dynamic 7T MRI of the knee and ankle joints. METHODS: The pTx coil has a U-shaped dual-row configuration (200 mm overall length longitudinally) that allows static and dynamic imaging of the knee and ankle joints at various postures and during active movements...
June 22, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28642265/the-initial-area-under-the-curve-derived-from-dynamic-contrast-enhanced-mri-improves-prognosis-prediction-in-glioblastoma-with-unmethylated-mgmt-promoter
#6
Y S Choi, S S Ahn, H-J Lee, J H Chang, S-G Kang, E H Kim, S H Kim, S-K Lee
BACKGROUND AND PURPOSE: Although perfusion and permeability MR parameters have known to have prognostic value, they have reproducibility issues. Our aim was to evaluate whether the initial area under the time-to-signal intensity curve (IAUC) derived from dynamic contrast-enhanced MR imaging can improve prognosis prediction in patients with glioblastoma with known MGMT status. MATERIALS AND METHODS: We retrospectively examined 88 patients with glioblastoma who underwent preoperative dynamic contrast-enhanced MR imaging...
June 22, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28641819/dynamic-contrast-enhanced-mr-imaging-of-carotid-vasa-vasorum-in-relation-to-coronary-and-cerebrovascular-events
#7
Juan Wang, Huijun Chen, Jie Sun, Daniel S Hippe, Huawei Zhang, Shengyuan Yu, Jianming Cai, Leixing Xie, Bao Cui, Chun Yuan, Xihai Zhao, Weimin Yuan, Hongbin Liu
BACKGROUND AND AIMS: Dynamic contrast-enhanced MR imaging (DCE-MRI) provides a noninvasive approach to the functional status of carotid adventitial vasa vasorum. Contrast extravasation rate, or K(trans), derived from kinetic modeling of adventitial enhancement, has been correlated with plaque neovascularization and inflammation. This study sought to clarify the clinical implications of K(trans) by evaluating its relationship with documented cardiovascular events (CVE). METHODS: Seventy patients with carotid plaque at clinical ultrasound examination were recruited and imaged with a previously-described bright-blood DCE-MRI protocol (spatial resolution: 0...
June 3, 2017: Atherosclerosis
https://www.readbyqxmd.com/read/28641271/joint-attributes-and-event-analysis-for-multimedia-event-detection
#8
Zhigang Ma, Xiaojun Chang, Zhongwen Xu, Nicu Sebe, Alexander G Hauptmann
Semantic attributes have been increasingly used the past few years for multimedia event detection (MED) with promising results. The motivation is that multimedia events generally consist of lower level components such as objects, scenes, and actions. By characterizing multimedia event videos with semantic attributes, one could exploit more informative cues for improved detection results. Much existing work obtains semantic attributes from images, which may be suboptimal for video analysis since these image-inferred attributes do not carry dynamic information that is essential for videos...
June 15, 2017: IEEE Transactions on Neural Networks and Learning Systems
https://www.readbyqxmd.com/read/28640847/heart-rate-lowering-treatment-leads-to-a-reduction-in-vulnerable-plaque-features-in-atherosclerotic-rabbits
#9
Raf H M van Hoof, Evelien Hermeling, Judith C Sluimer, Julie Salzmann, Arnold P G Hoeks, Jérôme Roussel, Mat J A P Daemen, Harry Struijker-Boudier, Joachim E Wildberger, Sylvia Heeneman, M Eline Kooi
OBJECTIVE: To investigate the effect of a heart rate (HR) lowering agent (Ivabradine) on features of atherosclerotic plaque vulnerability with magnetic resonance imaging (MRI), ultrasound imaging, and histology. APPROACH AND RESULTS: Atherosclerosis was induced in the abdominal aorta of 19 rabbits. Nine rabbits were treated with Ivabradine (17 mg/kg/day) during the entire study period. At week 14, imaging was performed. Plaque size was quantified on contrast-enhanced T1-weighted MR images...
2017: PloS One
https://www.readbyqxmd.com/read/28639721/trpv4-channels-contribute-to-calcium-transients-in-astrocytes-and-neurons-during-peri-infarct-depolarizations-in-a-stroke-model
#10
Cordula Rakers, Matthias Schmid, Gabor C Petzold
Stroke is one of the leading causes of death and long-term disability. In the penumbra, that is, the area surrounding the infarct core, peri-infarct depolarizations (PIDs) are accompanied by strong intracellular calcium elevations in astrocytes and neurons, thereby negatively affecting infarct size and clinical outcome. The dynamics of PIDs and the cellular pathways that are involved during PID formation and progression remain incompletely understood. We have previously shown that inositol triphosphate-gated calcium release from internal stores is a major component of PID-related astroglial calcium signals, but whether external calcium influx through membrane-localized channels also contributes to PIDs has remained unclear...
June 22, 2017: Glia
https://www.readbyqxmd.com/read/28639300/multiparametric-mri-of-the-breast-a-review
#11
REVIEW
Maria Adele Marino, Thomas Helbich, Pascal Baltzer, Katja Pinker-Domenig
During their development, cancers acquire several functional capabilities, which are defined as the hallmarks of cancer. For a deeper understanding of the hallmarks of cancer, and, consequently, improved personalized patient care, diagnostic tests must be multilayered and complex to identify the relevant underlying processes of cancer development and progression. In this context, magnetic resonance imaging (MRI) has emerged as an exceptionally powerful, versatile, and precise imaging technique. MRI of the breast is an essential tool in breast imaging, with multiple indications...
June 22, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28638483/thermoacoustic-imaging-and-therapy-guidance-based-on-ultra-short-pulsed-microwave-pumped-thermoelastic-effect-induced-with-superparamagnetic-iron-oxide-nanoparticles
#12
Liewei Wen, Sihua Yang, Junping Zhong, Quan Zhou, Da Xing
Multifunctional nanoparticle-mediated imaging and therapeutic techniques are promising modalities for accurate localization and targeted treatment of cancer in clinical settings. Thermoacoustic (TA) imaging is highly sensitive to detect the distribution of water, ions or specific nanoprobes and provides excellent resolution, good contrast and superior tissue penetrability. TA therapy is a potential non-invasive approach for the treatment of deep-seated tumors. In this study, human serum albumin (HSA)-functionalized superparamagnetic iron oxide nanoparticle (HSA-SPIO) is used as a multifunctional nanoprobe with clinical application potential for MRI, TA imaging and treatment of tumor...
2017: Theranostics
https://www.readbyqxmd.com/read/28637508/hyperpolarized-13-c-urea-myocardial-first-pass-perfusion-imaging-using-velocity-selective-excitation
#13
Maximilian Fuetterer, Julia Busch, Sophie M Peereboom, Constantin von Deuster, Lukas Wissmann, Miriam Lipiski, Thea Fleischmann, Nikola Cesarovic, Christian T Stoeck, Sebastian Kozerke
BACKGROUND: A velocity-selective binomial excitation scheme for myocardial first-pass perfusion measurements with hyperpolarized (13)C substrates, which preserves bolus magnetization inside the blood pool, is presented. The proposed method is evaluated against gadolinium-enhanced (1)H measurements in-vivo. METHODS: The proposed excitation with an echo-planar imaging readout was implemented on a clinical CMR system. Dynamic myocardial stress perfusion images were acquired in six healthy pigs after bolus injection of hyperpolarized (13)C urea with the velocity-selective vs...
June 21, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/28637186/cpg-and-methylation-dependent-dna-binding-and-dynamics-of-the-methylcytosine-binding-domain-2-protein-at-the-single-molecule-level
#14
Hai Pan, Stephanie M Bilinovich, Parminder Kaur, Robert Riehn, Hong Wang, David C Williams
The methylcytosine-binding domain 2 (MBD2) protein recruits the nucleosome remodeling and deacetylase complex (NuRD) to methylated DNA to modify chromatin and regulate transcription. Importantly, MBD2 functions within CpG islands that contain 100s to 1000s of potential binding sites. Since NuRD physically rearranges nucleosomes, the dynamic mobility of this complex is directly related to function. In these studies, we use NMR and single-molecule atomic force microscopy and fluorescence imaging to study DNA binding dynamics of MBD2...
June 20, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28631203/assessment-of-mri-contrast-agent-concentration-by-quantitative-susceptibility-mapping-qsm-application-to-estimation-of-cerebral-blood-volume-during-steady-state
#15
Emelie Lind, Linda Knutsson, Robin Kämpe, Freddy Ståhlberg, Ronnie Wirestam
OBJECTIVE: One major issue in dynamic susceptibility contrast MRI (DSC-MRI) is to accurately determine contrast agent (CA) concentration, since T2* relaxivity in vivo is generally unknown and varies between blood and tissue. In this study, quantitative susceptibility mapping (QSM) was used for quantification of CA concentration. MATERIALS AND METHODS: A DSC-MRI protocol, including phase data acquisition, was applied to 20 healthy volunteers in a test-retest study...
June 19, 2017: Magma
https://www.readbyqxmd.com/read/28631142/parametric-imaging-of-11-c-flumazenil-binding-in-the-rat-brain
#16
Isadora Lopes Alves, David Vállez Vállez García, Andrea Parente, Janine Doorduin, Ana Maria Marques da Silva, Michel Koole, Rudi Dierckx, Antoon Willemsen, Ronald Boellaard
PURPOSE: This study evaluates the performance of several parametric methods for assessing [(11)C]flumazenil binding distribution in the rat brain. PROCEDURES: Dynamic (60 min) positron emission tomography data with metabolite-corrected plasma input function were retrospectively analyzed (male Wistar rats, n = 10). Distribution volume (V T) images were generated from basis function method (BFM), Logan graphical analysis (Logan), and spectral analysis (SA). Using the pons as pseudo-reference tissue, binding potential (BP ND and DVR-1) images were obtained from receptor parametric imaging algorithms (RPM and SRTM2) and reference Logan (RLogan)...
June 19, 2017: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
https://www.readbyqxmd.com/read/28630234/multiparametric-model-for-penumbral-flow-prediction-in-acute-stroke
#17
Michelle Livne, Tabea Kossen, Vince I Madai, Olivier Zaro-Weber, Walter Moeller-Hartmann, Kim Mouridsen, Wolf-Dieter Heiss, Jan Sobesky
BACKGROUND AND PURPOSE: Identification of salvageable penumbra tissue by dynamic susceptibility contrast magnetic resonance imaging is a valuable tool for acute stroke patient stratification for treatment. However, prior studies have not attempted to combine the different perfusion maps into a predictive model. In this study, we established a multiparametric perfusion imaging model and cross-validated it using positron emission tomography perfusion for detection of penumbral flow. METHODS: In a retrospective analysis of 17 subacute stroke patients with consecutive magnetic resonance imaging and H2O15 positron emission tomography scans, perfusion maps of cerebral blood flow, cerebral blood volume, mean transit time, time-to-maximum, and time-to-peak were constructed and combined using a generalized linear model (GLM)...
June 19, 2017: Stroke; a Journal of Cerebral Circulation
https://www.readbyqxmd.com/read/28628422/t1%C3%AF-weighted-dynamic-glucose-enhanced-mr-imaging-in-the-human-brain
#18
Daniel Paech, Patrick Schuenke, Christina Koehler, Johannes Windschuh, Sibu Mundiyanapurath, Sebastian Bickelhaupt, David Bonekamp, Philipp Bäumer, Peter Bachert, Mark E Ladd, Martin Bendszus, Wolfgang Wick, Andreas Unterberg, Heinz-Peter Schlemmer, Moritz Zaiss, Alexander Radbruch
Purpose To evaluate the ability to detect intracerebral regions of increased glucose concentration at T1ρ-weighted dynamic glucose-enhanced (DGE) magnetic resonance (MR) imaging at 7.0 T. Materials and Methods This prospective study was approved by the institutional review board. Nine patients with newly diagnosed glioblastoma and four healthy volunteers were included in this study from October 2015 to July 2016. Adiabatically prepared chemical exchange-sensitive spin-lock imaging was performed with a 7.0-T whole-body unit with a temporal resolution of approximately 7 seconds, yielding the time-resolved DGE contrast...
June 16, 2017: Radiology
https://www.readbyqxmd.com/read/28627331/dynamic-transmit-receive-beamforming-by-spatial-matched-filtering-for-ultrasound-imaging-with-plane-wave-transmission
#19
Yuling Chen, Yang Lou, Jesse Yen
During conventional ultrasound imaging, the need for multiple transmissions for one image and the time of flight for a desired imaging depth limit the frame rate of the system. Using a single plane wave pulse during each transmission followed by parallel receive processing allows for high frame rate imaging. However, image quality is degraded because of the lack of transmit focusing. Beamforming by spatial matched filtering (SMF) is a promising method which focuses ultrasonic energy using spatial filters constructed from the transmit-receive impulse response of the system...
July 2017: Ultrasonic Imaging
https://www.readbyqxmd.com/read/28627037/quantitative-gd-dota-uptake-from-cerebrospinal-fluid-into-rat-brain-using-3d-vfa-spgr-at-9-4t
#20
Hedok Lee, Kristian Mortensen, Simon Sanggaard, Palle Koch, Hans Brunner, Bjørn Quistorff, Maiken Nedergaard, Helene Benveniste
PURPOSE: We propose a quantitative technique to assess solute uptake into the brain parenchyma based on dynamic contrast-enhanced MRI (DCE-MRI). With this approach, a small molecular weight paramagnetic contrast agent (Gd-DOTA) is infused in the cerebral spinal fluid (CSF) and whole brain gadolinium concentration maps are derived. METHODS: We implemented a 3D variable flip angle spoiled gradient echo (VFA-SPGR) longitudinal relaxation time (T1) technique, the accuracy of which was cross-validated by way of inversion recovery rapid acquisition with relaxation enhancement (IR-RARE) using phantoms...
June 19, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
keyword
keyword
74491
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"