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MR contrast agent

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https://www.readbyqxmd.com/read/28634084/drug-delivery-to-melanoma-brain-metastases-can-current-challenges-lead-to-new-opportunities
#1
Gautham Gampa, Shruthi Vaidhyanathan, Jann N Sarkaria, William F Elmquist
Melanoma has a high propensity to metastasize to the brain, and patients with melanoma brain metastases (MBM) have an extremely poor prognosis. The recent approval of several molecularly-targeted agents (e.g., BRAF, MEK inhibitors) and biologics (anti-CTLA-4, anti-PD-1 and anti-PD-L1 antibodies) has brought new hope to patients suffering from this formerly untreatable and lethal disease. Importantly, there have been recent reports of success in some clinical studies examining the efficacy of both targeted agents and immunotherapies that show similar response rates in both brain metastases and extracranial disease...
June 17, 2017: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
https://www.readbyqxmd.com/read/28630340/enhancing-t1-magnetic-resonance-imaging-contrast-with-internalized-gadolinium-iii-in-a-multilayer-nanoparticle
#2
Valeria S Marangoni, Oara Neumann, Luke Henderson, Caterina C Kaffes, Hui Zhang, Runmin Zhang, Sandra Bishnoi, Ciceron Ayala-Orozco, Valtencir Zucolotto, James A Bankson, Peter Nordlander, Naomi J Halas
Multifunctional nanoparticles for biomedical applications have shown extraordinary potential as contrast agents in various bioimaging modalities, near-IR photothermal therapy, and for light-triggered therapeutic release processes. Over the past several years, numerous studies have been performed to synthesize and enhance MRI contrast with nanoparticles. However, understanding the MRI enhancement mechanism in a multishell nanoparticle geometry, and controlling its properties, remains a challenge. To systematically examine MRI enhancement in a nanoparticle geometry, we have synthesized MRI-active Au nanomatryoshkas...
June 19, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28627754/labeling-and-magnetic-resonance-imaging-of-exosomes-isolated-from-adipose-stem-cells
#3
Alice Busato, Roberta Bonafede, Pietro Bontempi, Ilaria Scambi, Lorenzo Schiaffino, Donatella Benati, Manuela Malatesta, Andrea Sbarbati, Pasquina Marzola, Raffaella Mariotti
Adipose stem cells (ASC) represent a promising therapeutic approach for neurodegenerative diseases. Most biological effects of ASC are probably mediated by extracellular vesicles, such as exosomes, which influence the surrounding cells. Current development of exosome therapies requires efficient and noninvasive methods to localize, monitor, and track the exosomes. Among imaging methods used for this purpose, magnetic resonance imaging (MRI) has advantages: high spatial resolution, rapid in vivo acquisition, and radiation-free operation...
June 19, 2017: Current Protocols in Cell Biology
https://www.readbyqxmd.com/read/28626199/oxygen-and-glucose-as-stimulation-agents-for-bold-functional-mr-imaging-of-rabbit-liver-a-feasibility-study
#4
Fang Yuan, Bin Song, Zixing Huang, Xijiao Liu, Chunchao Xia
PURPOSE: To assess the feasibility of using oxygen and glucose as stimulating agents in blood-oxygen-level-dependent (BOLD) Functional Magnetic Resonance Imaging (fMRI) of rabbit liver and analyze the impacts by blood flow. METHODS: Pure oxygen inhalation, intravenous injection and oral administration of glucose were given to 11 New Zealand white rabbits to compare the differences of liver T2*, aortic flow (AF), portal vein flow (PVF), aortic area (AA) and portal vein area (PVA) before and at 5 min, 10 min, 20 min, 30 min after administrations...
June 16, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/28619842/cumulative-dose-of-macrocyclic-gadolinium-based-contrast-agent-improves-detection-of-enhancing-lesions-in-patients-with-multiple-sclerosis
#5
A Rovira, C Auger, E Huerga, J F Corral, R Mitjana, J Sastre-Garriga, M Tintoré, X Montalban
BACKGROUND AND PURPOSE: Gadolinium-enhanced MR imaging is currently the reference standard for detecting active inflammatory lesions in patients with multiple sclerosis. The sensitivity of MR imaging for this purpose may vary according to the physicochemical characteristics of the contrast agent used and the acquisition strategy. The purpose of this study was to compare detection of gadolinium- enhancing lesions or active disease following a single or cumulative dose of a macrocyclic gadolinium-based contrast agent with different image acquisition delays in patients with clinically isolated syndrome or relapsing multiple sclerosis...
June 15, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28616842/characterization-of-magneto-endosymbionts-as-mri-cell-labeling-and-tracking-agents
#6
Kimberly D Brewer, Ryan Spitler, Kayla R Lee, Andrea C Chan, Joyce C Barrozo, Abdul Wakeel, Chandler S Foote, Steven Machtaler, James Rioux, Juergen K Willmann, Papia Chakraborty, Bradley W Rice, Christopher H Contag, Caleb B Bell, Brian K Rutt
PURPOSE: Magneto-endosymbionts (MEs) show promise as living magnetic resonance imaging (MRI) contrast agents for in vivo cell tracking. Here we characterize the biomedical imaging properties of ME contrast agents, in vitro and in vivo. PROCEDURES: By adapting and engineering magnetotactic bacteria to the intracellular niche, we are creating magneto-endosymbionts (MEs) that offer advantages relative to passive iron-based contrast agents (superparamagnetic iron oxides, SPIOs) for cell tracking...
June 14, 2017: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
https://www.readbyqxmd.com/read/28613821/t1-t2-dual-modal-magnetic-resonance-imaging-from-molecular-basis-to-contrast-agents
#7
Zijian Zhou, Ruiliang Bai, Jeeva Munasinghe, Zheyu Shen, Liming Nie, Xiaoyuan Chen
Multimodal imaging strategies integrating manifold images have improved our ability to diagnose, to guide therapy, and to predict outcomes. Magnetic resonance imaging (MRI) is among the most widely used imaging technique in the clinic and can enable multiparameter anatomical demonstration of diagnosis. Due to the inherent black-and-white production of MR images, however, MRI detection is largely hampered by the occurrence of false-positive diagnoses. In this Perspective, we introduce the paradigm of manipulating the multiparameter MRI, T1-T2 dual-modal MRI, along with enhancement by specific contrast agents...
June 14, 2017: ACS Nano
https://www.readbyqxmd.com/read/28609204/surveillance-of-women-with-the-brca1-or-brca2-mutation-by-using-biannual-automated-breast-us-mr-imaging-and-mammography
#8
Jan C M van Zelst, Roel D M Mus, Gwendolyn Woldringh, Matthieu J C M Rutten, Peter Bult, Suzan Vreemann, Mathijn de Jong, Nico Karssemeijer, Nicoline Hoogerbrugge, Ritse M Mann
Purpose To evaluate a multimodal surveillance regimen including yearly full-field digital (FFD) mammography, dynamic contrast agent-enhanced (DCE) magnetic resonance (MR) imaging, and biannual automated breast (AB) ultrasonography (US) in women with BRCA1 and BRCA2 mutations. Materials and Methods This prospective multicenter trial enrolled 296 carriers of the BRCA mutation (153 BRCA1 and 128 BRCA2 carriers, and 15 women with first-degree untested relatives) between September 2010 and November 2012, with follow-up until November 2015...
June 13, 2017: Radiology
https://www.readbyqxmd.com/read/28598900/interleaved-mapping-of-temperature-and-longitudinal-relaxation-rate-to-monitor-drug-delivery-during-magnetic-resonance-guided-high-intensity-focused-ultrasound-induced-hyperthermia
#9
Esther Kneepkens, Edwin Heijman, Jochen Keupp, Steffen Weiss, Klaas Nicolay, Holger Grüll
OBJECTIVES: Magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) is a method to heat lesions noninvasively to a stable, elevated temperature and a well-suited method to induce local hyperthermia (41°C-43°C) in deep-seated tissues. Magnetic Resonance (MR) imaging provides therapy planning on anatomical images and offers temperature feedback based on near-real-time MR thermometry. Although constant acquisition of MR thermometry data is crucial to ensure prolonged hyperthermia, it limits the freedom to perform measurements of other MR parameters, which are of interest during hyperthermia treatments...
June 8, 2017: Investigative Radiology
https://www.readbyqxmd.com/read/28590565/three-dimensional-mr-reconstruction-of-high-contrast-magnetic-susceptibility-by-the-variational-born-iterative-method-based-on-the-magnetic-field-volume-integral-equation
#10
Shengnan Li, Ronghan Hong, Na Liu, Jianhua Zhang, Lin Chen, Youyu Zhang, Zhiru Yu, Qing Huo Liu
PURPOSE: To provide high-quality and high-contrast magnetic susceptibility mapping, a 3D MR reconstruction method for magnetic susceptibility based on the magnetic field volume integral equation with the variational Born iterative method (VBIM) is developed. METHODS: Three-dimensional magnetic susceptibility is reconstructed from the positive rotating magnetic field component H1+ of the radiofrequency field acquired by B1 mapping. The stabilized biconjugate gradient fast Fourier transform (BCGS-FFT) method is implemented in the forward problem to solve for the magnetic field, and the conjugate gradient fast Fourier transform method is implemented in the inverse problem to reconstruct the magnetic susceptibility distribution...
June 7, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28588582/nanoparticle-based-magnetic-resonance-imaging-on-tumor-associated-macrophages-and-inflammation
#11
REVIEW
Natalie J Serkova
The inflammatory response, mediated by tissue-resident or newly recruited macrophages, is an underlying pathophysiological condition for many diseases, including diabetes, obesity, neurodegeneration, atherosclerosis, and cancer. Paradoxically, inflammation is a double-edged sword in oncology. Macrophages are, generally speaking, the major drivers of inflammatory insult. For many solid tumors, high density of cells expressing macrophage-associated markers have generally been found in association with a poor clinical outcome, characterized by inflamed microenvironment, a high level of dissemination and resistance to conventional chemotherapies...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28585312/manganese-based-layered-double-hydroxide-nanoparticles-as-a-t1-mri-contrast-agent-with-ultrasensitive-ph-response-and-high-relaxivity
#12
Bei Li, Zi Gu, Nyoman Kurniawan, Weiyu Chen, Zhi Ping Xu
Recently, Mn(II)-containing nanoparticles have been explored widely as an attractive alternative to Gd(III)-based T1 -weighted magnetic resonance imaging (MRI) contrast agents (CAs) for cancer diagnosis. However, as far as it is known, no Mn-based MRI CAs have been reported to sensitively respond to a very weakly acidic environment (pH 6.5-7.0, i.e., the pH range in a tumor microenvironment) with satisfactory imaging performance. Here, recently devised pH-ultrasensitive Mn-based layered double hydroxide (Mn-LDH) nanoparticles with superb longitudinal relaxivity (9...
June 6, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28585238/three-dimensional-mapping-of-brain-venous-oxygenation-using-r2-oximetry
#13
Deng Mao, Yang Li, Peiying Liu, Shin-Lei Peng, Jay J Pillai, Hanzhang Lu
PURPOSE: Cerebral venous oxygenation (Yv ) is an important biomarker for brain diseases. This study aims to develop an R2*-based MR oximetry that can measure cerebral Yv in 3D. METHODS: This technique separates blood signal from tissue by velocity-encoding phase contrast and measures the R2* of pure blood by multi-gradient-echo acquisition. The blood R2* was converted to Yv using an R2*-versus-oxygenation (Y) calibration curve, which was obtained by in vitro bovine blood experiments...
June 6, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28581764/tumor-targeted-and-clearable-human-protein-based-mri-nanoprobes
#14
Yang Zhao, Jing Peng, Jingjin Li, Ling Huang, Jingyi Yang, Kai Huang, Hewen Li, Ning Jiang, Shaokuan Zheng, Xuening Zhang, Yuanjie Niu, Gang Han
Biocompatibility, targeting, and clearance are key challenges in the design of new MRI contrast agents. Herein, we report on a tumor-targeting, gadolinium biomineralized human transferrin (Tf) protein-based nanoparticle (Gd@Tf NP) for MRI use. As compared to the conventionally used gadolinium chelates, the resultant Gd@Tf NPs possess outstanding chemical stability and exhibited superior longitudinal relaxation. More importantly, our MR images show that Gd@Tf indeed retained the natural tumor targeting ability and the subsequent tumor retrieval biofunctions of Tf...
June 5, 2017: Nano Letters
https://www.readbyqxmd.com/read/28579267/preliminary-results-of-a-simplified-breast-mri-protocol-to-characterize-breast-lesions-comparison-with-a-full-diagnostic-protocol-and-a-review-of-the-current-literature
#15
Valeria Romeo, Renato Cuocolo, Raffaele Liuzzi, Albina Riccardi, Antonello Accurso, Alessandra Acquaviva, Roberta Buonocore, Massimo Imbriaco
RATIONALE AND OBJECTIVES: This study aimed to investigate whether a simplified breast magnetic resonance imaging (MRI) protocol consisting of a localizer, one precontrast sequence, and three time-point postcontrast sequences (at 28 seconds, 84 seconds and 252 seconds after the contrast agent administration) is suitable for the characterization of breast lesions as compared to a full diagnostic protocol (FDP). This study also aimed to review the current literature concerning abbreviated breast MRI protocols and offer an alternative protocol...
June 1, 2017: Academic Radiology
https://www.readbyqxmd.com/read/28577726/updates-in-hepatic-oncology-imaging
#16
REVIEW
Pallavi Pandey, Heather Lewis, Ankur Pandey, Carl Schmidt, Mary Dillhoff, Ihab R Kamel, Timothy M Pawlik
The utilization of advanced imaging modalities play an important role in the detection and differentiation of benign and malignant hepatic lesions. Imaging characteristics of hepatic tumors can sometimes be atypical, often leading to diagnostic challenges. Recent technical improvements in contrast enhanced ultrasound (CEUS), computed tomography (CT), and magnetic resonance imaging (MRI) have helped to better characterize hepatic lesions. For example, contrast agents used in US can now better delineate liver lesions, while the ability to reliably produce multiplanar and 3-D reconstructions through the use of MDCT provides an additional advantage in the context of therapeutic decision making for patients with hepatic lesions...
June 2017: Surgical Oncology
https://www.readbyqxmd.com/read/28558795/non-caloric-sweetener-provides-magnetic-resonance-imaging-contrast-for-cancer-detection
#17
Puneet Bagga, Mohammad Haris, Kevin D'Aquilla, Neil E Wilson, Francesco M Marincola, Mitchell D Schnall, Hari Hariharan, Ravinder Reddy
BACKGROUND: Image contrast enhanced by exogenous contrast agents plays a crucial role in the early detection, characterization, and determination of the precise location of cancers. Here, we investigate the feasibility of using a non-nutritive sweetener, sucralose (commercial name, Splenda), as magnetic resonance imaging (MRI) contrast agent for cancer studies. METHODS: High-resolution nuclear-magnetic-resonance spectroscopy and MR studies on sucralose solution phantom were performed to detect the chemical exchange saturation transfer (CEST) property of sucralose hydroxyl protons with bulk water (sucCEST)...
May 30, 2017: Journal of Translational Medicine
https://www.readbyqxmd.com/read/28558297/mri-sensitive-contrast-agent-with-anticoagulant-activity-for-surface-camouflage-of-transplanted-pancreatic-islets
#18
Yong Hwa Hwang, Min Jun Kim, Dong Yun Lee
Pancreatic islet implantation in the liver is a promising approach for diabetes therapy. However, 70% of the islet mass fails to be engrafted in the liver due to the instant blood-mediated inflammatory reactions (IBMIR) resulting from direct contact between islet cells and the bloodstream. To overcome this issue, direct monitoring is very important for establishing prognosis after islet cell therapy. Here we established a new type of MR contrast agent with anticoagulant activity via heparin-immobilized superparamagnetic iron oxide (HSPIO)...
May 23, 2017: Biomaterials
https://www.readbyqxmd.com/read/28551145/a-magnetic-polypyrrole-iron-oxide-core-gold-shell-nanocomposite-for-multimodal-imaging-and-photothermal-cancer-therapy
#19
Lu Han, Yang Zhang, Yue Zhang, Yang Shu, Xu-Wei Chen, Jian-Hua Wang
For the purpose of improving the diagnosis and enhancing the photothermal therapeutic effect for cancer under near-infrared (NIR) laser irradiation, a novel magnetic therapeutic platform containing dual photothermal agents, polypyrrole (PPy) and gold nanoshell, is constructed. The nanostructure is composed of a magnetic PPy/Fe3O4-core and a gold nanoshell, which is capable of enhancing the contrast for both magnetic resonance (MR) and X-ray computed tomography (CT) imaging. By attaching Raman probes onto the surface of gold shell, the nanocomposites exhibit the potential to serve as surface-enhanced Raman scattering (SERS) active substrates for optical modality identification of cancer cell...
August 15, 2017: Talanta
https://www.readbyqxmd.com/read/28542553/quantitative-mri-for-analysis-of-peritumoral-edema-in-malignant-gliomas
#20
Ida Blystad, J B Marcel Warntjes, Örjan Smedby, Peter Lundberg, Elna-Marie Larsson, Anders Tisell
BACKGROUND AND PURPOSE: Damage to the blood-brain barrier with subsequent contrast enhancement is a hallmark of glioblastoma. Non-enhancing tumor invasion into the peritumoral edema is, however, not usually visible on conventional magnetic resonance imaging. New quantitative techniques using relaxometry offer additional information about tissue properties. The aim of this study was to evaluate longitudinal relaxation R1, transverse relaxation R2, and proton density in the peritumoral edema in a group of patients with malignant glioma before surgery to assess whether relaxometry can detect changes not visible on conventional images...
2017: PloS One
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