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MR contrast agent

Akinaga Sonoda, Norihisa Nitta, Keiko Tsuchiya, Ayumi Nitta-Seko, Shinichi Ohta, Hideji Otani, Kiyoshi Murata
Gadofosveset trisodium is available as a prolonged pooling vascular contrast agent for magnetic resonance imaging. As gadolinium (Gd)-based agents may increase the risk for nephrogenic systemic fibrosis in patients with severe renal insufficiency, the present study synthesized carboxymethyl-diethylaminoethyl dextran magnetite (CMEADM) particles as a blood-pooling, non-Gd‑based contrast agent. CMEADM particles carry a negative or positive charge due to the binding of amino and carboxyl groups to the hydroxyl group of dextran...
October 21, 2016: Molecular Medicine Reports
S Wagner, H Gufler, G Eichner, H Lanfermann
AIMS: To investigate if brain metastases and radiation injuries after stereotactic radiosurgery (SRS) have different signal intensity (SI) time courses up to 55 min after contrast agent application and if delayed contrast magnetic resonance imaging (MRI) contributes to improve diagnostic accuracy. MATERIALS AND METHODS: Thirty-four consecutive patients treated with SRS for cerebral metastases were prospectively enrolled in the study. T1-weighted images were acquired on a 3-Tesla MR unit at three time points, at 2 (TP1), 15 (TP2) and 55 (TP3) min after administering contrast agent...
October 21, 2016: Clinical Oncology: a Journal of the Royal College of Radiologists
Ting Zhang, Zhong-Zhen Su, Ping Wang, Tao Wu, Wen Tang, Er-Jiao Xu, Jin-Xiu Ju, Xian-Yue Quan, Rong-Qin Zheng
PURPOSE: To investigate the value of double contrast-enhanced ultrasonography (DCEUS) in the detection of periampullary cancer. MATERIALS AND METHODS: Ninety-nine patients with surgery or biopsy-proven periampullary cancer who underwent both DCEUS and magnetic resonance imaging (MRI) examinations before operation were enrolled in our study. DCEUS in which intravenous microbubbles were used in combination with oral contrast agent and MRI were performed preoperatively to make a detection diagnosis of periampullary cancer...
November 2016: European Journal of Radiology
Hye Jin Yoo, Sung Hwan Hong, Hye Yeon Oh, Ja-Young Choi, Hee Dong Chae, Joong Mo Ahn, Heung Sik Kang
Purpose To determine the agreement of fat-suppressed (FS) fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging and contrast material-enhanced (CE) T1-weighted MR imaging for the assessment of peripatellar synovitis. Materials and Methods The institutional review board approved this retrospective study and waived the requirement for patient informed consent. Thirty-three patients with knee pain underwent 3-T MR imaging. The protocol consisted of routine clinical sequences followed by the FLAIR FS sequence (inversion time, 2200 msec) and CE T1-weighted imaging...
October 24, 2016: Radiology
Jun-Qing Situ, Xiao-Juan Wang, Xiu-Liang Zhu, Xiao-Ling Xu, Xu-Qi Kang, Jing-Bo Hu, Chen-Ying Lu, Xiao-Ying Ying, Ri-Sheng Yu, Jian You, Yong-Zhong Du
Specific delivery of chemotherapy drugs and magnetic resonance imaging (MRI) contrast agent into tumor cells is one of the issues to highly efficient tumor targeting therapy and magnetic resonance imaging. Here, A54 peptide-functionalized poly(lactic-co-glycolic acid)-grafted dextran (A54-Dex-PLGA) was synthesized. The synthesized A54-Dex-PLGA could self-assemble to form micelles with a low critical micelle concentration of 22.51 μg. mL(-1) and diameter of about 50 nm. The synthetic A54-Dex-PLGA micelles can encapsulate doxorubicin (DOX) as a model anti-tumor drug and superparamagnetic iron oxide (SPIO) as a contrast agent for MRI...
October 24, 2016: Scientific Reports
Svetlana V Fedorenko, Svetlana L Grechkina, Asiya R Mustafina, Kirill V Kholin, Alexey S Stepanov, Irek R Nizameev, Ildus E Ismaev, Marsil K Kadirov, Rustem R Zairov, Alfia N Fattakhova, Rustem R Amirov, Svetlana E Soloveva
The present work introduces deliberate synthesis of Gd(III)-doped silica nanoparticles with high relaxivity at magnetic field strengths below 1.5T. Modified microemulsion water-in-oil procedure was used in order to achieve superficial localization of Gd(III) complexes within 40-55nm sized silica spheres. The relaxivities of the prepared nanoparticles were measured at 0.47, 1.41 and 1.5T with the use of both NMR analyzer and whole body NMR scanner. Longitudinal relaxivities of the obtained silica nanoparticles reveal significant dependence on the confinement mode, changing from 4...
October 14, 2016: Colloids and Surfaces. B, Biointerfaces
J Wu, S Dehkharghani, F Nahab, J Allen, D Qiu
BACKGROUND AND PURPOSE: Measuring cerebrovascular reactivity with the use of vasodilatory stimuli, such as acetazolamide, is useful for chronic cerebrovascular steno-occlusive disease. The purpose of this study was to evaluate the effects of acetazolamide on the assessment of hemodynamic impairment and functional connectivity by using noninvasive resting-state blood oxygen level-dependent MR imaging. MATERIALS AND METHODS: A 20-minute resting-state blood oxygen level-dependent MR imaging scan was acquired with infusion of acetazolamide starting at 5 minutes after scan initiation...
October 6, 2016: AJNR. American Journal of Neuroradiology
J Gallo, N Vasimalai, M T Fernandez-Arguelles, M Bañobre-López
Diagnosis by MRI is frequently non-trivial due to the low sensitivity of the technique. Signal enhancing contrast agents (CAs) are used to aid in the analysis of MR images. We present here a simple protocol for the preparation of responsive CAs based on Mn nanosheets. Mn nanostructures presented here undergo a chemical and structural change in the presence of altered physiological conditions that activate their signal. This strategy allows for a reduction of background, increasing the sensitivity of the technique...
October 18, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Arnav Mehta, Ketan Ghaghada, Srinivasan Mukundan
The first generation of cross-sectional brain imaging using computed tomography (CT), ultrasonography, and eventually MR imaging focused on determining structural or anatomic changes associated with brain disorders. The current state-of-the-art imaging, functional imaging, uses techniques such as CT and MR perfusion that allow determination of physiologic parameters in vivo. In parallel, tissue-based genomic, transcriptomic, and proteomic profiling of brain tumors has created several novel and exciting possibilities for molecular targeting of brain tumors...
November 2016: Magnetic Resonance Imaging Clinics of North America
Norihide Yoneda, Osamu Matsui, Azusa Kitao, Kazuto Kozaka, Satoshi Kobayashi, Motoko Sasaki, Kotaro Yoshida, Dai Inoue, Tetsuya Minami, Toshifumi Gabata
Gadoxetic acid is a contrast agent for magnetic resonance (MR) imaging with hepatocyte-specific properties and is becoming increasingly important in detection and characterization of hepatocellular carcinoma and benign hepatocellular nodules, including focal nodular hyperplasia (FNH), nodular regenerative hyperplasia (NRH), hepatocellular adenoma (HCA), and dysplastic nodule. In these hepatocellular nodules, a positive correlation between the grade of membranous uptake transporter organic anion-transporting polypeptide (OATP) 1B3 expression and signal intensity in the hepatobiliary (HB) phase has been verified...
October 14, 2016: Radiographics: a Review Publication of the Radiological Society of North America, Inc
Mansi R Shah, Milana Flusberg, Viktoriya Paroder, Alla M Rozenblit, Victoria Chernyak
PURPOSE: The purpose was to compare hepatic arterial phase (HAP) respiratory motion artifact (RMA) between gadoxetate, gadobutrol, gadopentetate, and gadobenate. MATERIALS/METHODS: Two hundred cases of each gadolinium agent were included. RMA was assigned using 5-point Likert scale (1=no motion, 5=extreme motion) on precontrast and HAP. RMA increase (increase ≥1 on HAP from precontrast) was the outcome in logistic regression. RESULTS: Odds of RMA increase for gadoxetate were 5...
September 13, 2016: Clinical Imaging
Tobias Heer, Stephanie Reiter, Markus Trißler, Berthold Höfling, Florian von Knobelsdorff-Brenkenhoff, Günter Pilz
PURPOSE: To systematically investigate the effect of sublingual glyceryl trinitrate (nitroglycerin=nitro=glyceryl trinitrate=GTN=C3 H5 N3 O9 [NTG]) on the diagnostic performance of MR coronary artery imaging (MRCA) to detect relevant coronary artery disease (CAD). MATERIALS AND METHODS: Thirty-five healthy volunteers and 25 patients with suspected or proven CAD (all in sinus rhythm) underwent MRCA before and after NTG using a contrast-agent free, three-dimensional, navigator-based, steady state free precession acquisition (voxel size 1...
October 12, 2016: Journal of Magnetic Resonance Imaging: JMRI
Jin Hee Kim, Ji-Yeon Suh, Dong-Cheol Woo, Yu Sub Sung, Woo-Chan Son, Yoon Seok Choi, Sang Joon Pae, Jeong Kon Kim
Contrast enhancement by an extracellular-fluid contrast agent (CA) (Gd-DOTA) depends primarily on the blood-brain-barrier permeability (bp), and transverse-relaxation change caused by intravascular T2 CA (superparamagnetic iron oxide nanoparticles, SPIONs) is closely associated with the blood volume (BV). Pharmacokinetic (PK) vascular characterization based on single-CA-using dynamic contrast-enhanced MRI (DCE-MRI) has shown significant measurement variation according to the molecular size of the CA. Based on this recognition, this study used a dual injection of Gd-DOTA and SPIONs for tracing the changes of bp and BV in C6 glioma growth (Days 1 and 7 after the tumor volume reached 2 mL)...
October 10, 2016: NMR in Biomedicine
Zhijuan Xiong, Yue Wang, Jingyi Zhu, Yao He, Jiao Qu, Christiane Effenberg, Jindong Xia, Dietmar Appelhans, Xiangyang Shi
We report the design of the fourth generation poly(propylene imine) (PPI) glycodendrimers for magnetic resonance (MR) imaging applications. The glycodendrimers were designed to have a densely organized maltose shell (MAL DS) and several tetraazacyclododecane tetraacetic acid (DOTA) ligands that were attached to the periphery of the PPI dendrimers for Gd(iii) chelation. We show that the formed MAL DS-modified PPI dendrimers possess good cytocompatibility and hemocompatibility in the studied concentration range...
October 18, 2016: Biomaterials Science
M Ravichandran, Goldie Oza, S Velumani, Jose Tapia Ramirez, Francisco Garcia-Sierra, Norma Barragan Andrade, A Vera, L Leija, Marco A Garza-Navarro
A multifunctional magneto-plasmonic CoFe2O4@Au core-shell nanoparticle was developed by iterative-seeding based method. This nanocargo consists of a cobalt ferrite kernel as a core (Nk) and multiple layers of gold as a functionalizable active stratum, (named as Nk@A after fifth iteration). Nk@A helps in augmenting the physiological stability and enhancing surface plasmon resonance (SPR) property. The targeted delivery of Doxorubicin using Nk@A as a nanopayload is demonstrated in this report. The drug release profile followed first order rate kinetics optimally at pH 5...
October 10, 2016: Scientific Reports
Nozomu Murata, Kiyoko Murata, Luis F Gonzalez-Cuyar, Kenneth Maravilla
Until recognition of the association of nephrogenic systemic fibrosis (NSF) and gadolinium based contrast agents (GBCA) in 2006, these agents were considered extremely safe and without major adverse effects. Even after the recognition of NSF, most physicians considered all GBCAs to be safe when used in patients with normal renal function. This belief has been called into question with the discovery by Kanda in 2014 that Gd is deposited in brain tissue in patients with normal kidney function. Since that initial report, there have been a number of important studies analyzing the effects of various GBCAs in brain using MR T1 signal intensity measurements and postmortem tissue analyses with inductively coupled plasma mass spectrometry...
October 5, 2016: Magnetic Resonance Imaging
Asifkhan Shanavas, Sisini Sasidharan, Dhirendra Bahadur, Rohit Srivastava
Hybrid nanoparticles with magnetic poly (lactide-co-glycolide) (PLGA) nanoparticle 'core', surface modified with folate-chitosan (fol-cht) conjugate 'shell' are evaluated as simultaneous anti-cancer therapeutic and MRI contrast agent. The fol-cht conjugate is prepared using carbodiimide crosslinking chemistry at an optimized folate to amine (chitosan) molar ratio for further coating on PLGA nanoparticles loaded with docetaxel and well packed super paramagnetic iron oxide nanoparticles (SPIONs). Apart from possessing a targeting moiety, the coating provides a physical barrier to avoid undesired burst release of drug and also imparts sensitivity to acidic pH, due to protonated amine group dependent decondensation of the coating and subsequent drug release...
September 28, 2016: Journal of Colloid and Interface Science
Pengpeng Lei, Peng Zhang, Shuang Yao, Shuyan Song, Lile Dong, Xia Xu, Xiuling Liu, Kaimin Du, Jing Feng, Hongjie Zhang
Bioimaging probes have been extensive studied for many years, while it is still a challenge to further improve the image quality for precise diagnosis in clinical medicine. Here, monodisperse NaGdF4:Yb3+,Tm3+,x% Bi3+ (abbreviated as GYT-x% Bi3+, x = 0, 5, 10, 15, 20, 25, 30) upconversion nanoparticles (UCNPs) have been prepared through solvothermal method. The near-infrared upconversion emission intensity of GYT-25% Bi3+ has been enhanced remarkably than that of NaGdF4:Yb3+,Tm3+ (GYT) with a factor of ~60. Especially, the near-infrared upconversion emission band centered at 802 nm is 150 times stronger than the blue emission band of GYT-25% Bi3+ UCNPs...
October 3, 2016: ACS Applied Materials & Interfaces
Bing Fan, Meijiao Li, Xiaoying Wang, Yufeng Xu, Feiyu Li, Laiyun Zhang, Jian Jiang, Yanyan Jiang
PURPOSE: To compare gadobutrol and gadopentetate dimeglumine (Gd-DTPA) contrast-enhanced magnetic resonance imaging (MRI) at 3T for visualizing brain metastases. MATERIALS AND METHODS: The present randomized study included 60 consecutive patients with known or suspected brain metastases from systemic malignancies. Two enhanced cerebral MR scans were performed in each patient within an interval of 2-5 days using different contrast agents (gadobutrol or Gd-DTPA) at 3T...
October 3, 2016: Journal of Magnetic Resonance Imaging: JMRI
Joana Ramalho, Miguel Ramalho, Mamdoh AlObaidy, Richard C Semelka
Over the last 2years several studies have been published regarding gadolinium deposition in brain structures in patients with normal renal function after repeated administrations of gadolinium-based contrast agents (GBCAs). Most of the publications are magnetic resonance imaging (MRI) based retrospective studies, where gadolinium deposition may be indirectly measured by evaluating changes in T1 signal intensity (SI) in brain tissue, particularly in the dentate nucleus (DN) and/or globus pallidi (GP). The direct correlation between T1 signal changes and gadolinium deposition was validated by human pathology studies...
September 27, 2016: Magnetic Resonance Imaging
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