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MRI contrast agent

Anton S Becker, Cristina Rossi
Arterial spin labeling (ASL) MRI allows the quantification of tissue perfusion without administration of exogenous contrast agents. Patients with reduced renal function or other contraindications to Gadolinium-based contrast media may benefit from the non-invasive monitoring of tissue microcirculation. So far, only few studies have investigated the sensitivity, the specificity and the reliability of the ASL techniques for the assessment of renal perfusion. Moreover, only little is known about the interplay between ASL markers of perfusion and functional renal filtration parameters...
October 20, 2016: Nephron
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
Kuen-Lin Chen, Yao-Wei Yeh, Jian-Ming Chen, Yu-Jie Hong, Tsung-Lin Huang, Zu-Yin Deng, Chiu-Hsien Wu, Su-Hsien Liao, Li-Min Wang
Magnetoplasmonic nanoparticles, composed of a plasmonic layer and a magnetic core, have been widely shown as promising contrast agents for magnetic resonance imaging (MRI) applications. However, their application in low-field nuclear magnetic resonance (LFNMR) research remains scarce. Here we synthesised γ-Fe2O3/Au core/shell (γ-Fe2O3@Au) nanoparticles and subsequently used them in a homemade, high-Tc, superconducting quantum interference device (SQUID) LFNMR system. Remarkably, we found that both the proton spin-lattice relaxation time (T1) and proton spin-spin relaxation time (T2) were influenced by the presence of γ-Fe2O3@Au nanoparticles...
October 18, 2016: Scientific Reports
Tamilmani Vairapperumal, Ariya Saraswathy, Jayasree S Ramapurath, Sreeram Kalarical Janardhanan, Nair Balachandran Unni
Tetragonal (t)-LaVO4 has turned out to be a potential host for luminescent materials. Synthesis of t-LaVO4 till date has been based on chelating effect of EDTA making it not ideal for bioimaging applications. An alternative was proposed by us through the use of catechin. In recent times there is interest for new MRI contrast agents that can through appropriate doping function both as MRI contrast and optical/upconversion materials. It is generally believed that under appropriate doping, t-LaVO4 would be a better upconversion material than monoclinic (m)-LaVO4...
October 18, 2016: Scientific Reports
Christian H Roux, Violaine Foltz, Emmanuel Maheu, Gabriel Baron, Frederique Gandjbakhch, Cédric Lukas, Daniel Wendling, Damien Loeuille, Pierre Lafforgue, Liana Euler-Ziegler, Pascal Richette, Xavier Chevalier
OBJECTIVES: To explore the relationship between clinical findings, biologic biomarkers, conventional radiography and MRI in patients with painful hand OA. METHODS: The following patient baseline data from the DORA study (evaluating anti-TNF-α agents against painful hand OA) were used: clinical assessment (pain, swelling, stiffness and function: Dreiser functional hand index [FIHOA] and Cochin hand functional scale [CHFS]); measurement of biomarkers (cartilage oligomeric matrix protein (COMP), type IIA collagen N-propeptid (PIINP), hyaluronic acid (HA), ultrasensitive C-reactive protein (usCRP), tumour necrosis factor (TNF), interleukin (IL)-6, IL-1β and urinary CTXII); radiological staging (Verbruggen, Kallman, Kellgren-Lawrence); anatomical evaluation by contrast-enhanced MRI of proximal and distal interphalangeal joints of dominant hand...
September 18, 2016: Clinical and Experimental Rheumatology
Yuh-Feng Tsai, Ching-Wen Huang, Jo-Hua Chiang, Fuu-Jen Tsai, Yuan-Man Hsu, Chi-Cheng Lu, Chen-Yu Hsiao, Jai-Sing Yang
Gadolinium (Gd) compounds are important as magnetic resonance imaging (MRI) contrast agents, and are potential anticancer agents. However, no report has shown the effect of gadolinium chloride (GdCl3) on osteosarcoma in vitro. The present study investigated the apoptotic mechanism of GdCl3 on human osteosarcoma U-2 OS cells. Our results indicated that GdCl3 significantly reduced cell viability of U-2 OS cells in a concentration-dependent manner. GdCl3 led to apoptotic cell shrinkage and DNA fragmentation in U-2 OS cells as revealed by morphologic changes and TUNEL staining...
October 14, 2016: Oncology Reports
Juyoung Park, Muna Aryal, Natalia Vykhodtseva, Yong-Zhi Zhang, Nathan McDannold
Drug delivery in brain tumors is challenging because of the presence of blood-brain barrier (BBB) and the blood-tumor barrier (BTB). Focused ultrasound (FUS) combined with microbubbles can enhance the permeability of the BTB in brain tumors, as well as disrupting the BBB in the surrounding tissue. In this study, dynamic contrast-enhanced Magnetic Resonance Imaging (DCE-MRI) was used to characterize FUS-induced permeability changes in a rat glioma model and in the normal brain and to investigate the relationship between these changes and the resulting concentration of the chemotherapy agent doxorubicin (DOX)...
October 11, 2016: Journal of Controlled Release: Official Journal of the Controlled Release Society
Nandor K Pinter, Joshua P Klein, Laszlo L Mechtler
PURPOSE OF REVIEW: This article reviews recent research on gadolinium deposit formation in the brain linked to contrast-enhanced MRI studies. RECENT FINDINGS: Human and animal studies have confirmed the presence of gadolinium in the brain following the serial administration of gadolinium-based contrast agents. This is a relatively new and growing field of research primarily driven by concerns regarding unknown and potentially harmful side effects of gadolinium-based contrast agents...
October 2016: Continuum: Lifelong Learning in Neurology
Antonella Antonelli, Carla Sfara, Oliver Weber, Ulrich Pison, Elisabetta Manuali, Sonia Salamida, Mauro Magnani
AIM: The biomedical application of contrast agents based on superparamagnetic iron oxide nanoparticles is still limited because of their short intravascular half-life. The potential of red blood cells (RBCs) loaded with new ferucarbotran nanoparticles as magnetic contrast agents with longer blood retention time has been investigated. MATERIALS & METHODS: Ferucarbotran was loaded into RBCs by a procedure of hypotonic dialysis and isotonic resealing. Ferucarbotran amounts encapsulated in RBCs were determined by NMR...
October 14, 2016: Nanomedicine
Sophie Richard, Véronique Eder, Gianvito Caputo, Clément Journé, Phalla Ou, Julie Bolley, Liliane Louedec, Erwann Guenin, Laurence Motte, Nicola Pinna, Yoann Lalatonne
AIM: Tunable size ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles from 3 to 9 nm coated with polyethylene glycol phosphonate moieties have been designed for neovascularization MRI. MATERIALS & METHODS: USPIO were synthesized using a nonaqueous sol-gel method. An ischemia-reperfusion rat model has been chosen for neo-angiogenesis and scanned on MRI after injection of different sized USPIO. Histological studies have been performed for USPIO localization within the tissue...
October 14, 2016: Nanomedicine
Susanne M Kaiser, Oliver Harms, Martin Konar, Anne Staudacher, Anna Langer, Cetina Thiel, Martin Kramer, Sebastian Schaub, Kerstin H von Pückler
OBJECTIVES: To describe clinical, radiographic, and magnetic resonance imaging (MRI) findings in 16 dogs diagnosed with gastrocnemius musculotendinopathy. METHODS: Retrospective evaluation of medical records, radiographs, and MRI results, as well as follow-up completed by telephone questionnaire. RESULTS: Most dogs had chronic hindlimb lameness with no history of trauma or athletic activities. Clinical examination revealed signs of pain on palpation without stifle joint instability...
October 14, 2016: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
F Barchetti, A Stagnitti, V Megna, N Al Ansari, A Marini, D Musio, M L Monti, G Barchetti, V Tombolini, C Catalano, V Panebianco
OBJECTIVE: The aim of this study was to evaluate the accuracy of unenhanced whole-body MRI, including whole-body Diffusion Weighted Imaging (DWI), used as a diagnostic modality to detect  pathologic lymph nodes and skeletal metastases in patients with prostate cancer (PCa) undergoing restaging after primary treatment. PATIENTS AND METHODS: 152 male patients with biochemical recurrence after radical prostatectomy (RP) or external beam radiation therapy (EBRT) underwent MRI at a 1...
September 2016: European Review for Medical and Pharmacological Sciences
Haroon Ur Rashid, Marco Antonio Utrera Martines, Juliana Jorge, Paula Martin de Moraes, Muhammad Naveed Umar, Kamin Khan, Hanif Ur Rehman
Magnetic Resonance Imaging (MRI) is a noninvasive radiology technique used to examine the internal organs of human body. It is useful for the diagnosis of structural abnormalities in the body. Contrast agents are used to increase the sensitivity of this technique. 1,4,7,10-Tetraazacyclododecane (cyclen) is a macrocyclic tetraamine. Its derivatives act as useful ligands to produce stable complexes with Gd(3+) ion. Such chelates are investigated as MRI contrast agents. Free Gd(3+) ion is extremely toxic for in vivo use...
October 1, 2016: Bioorganic & Medicinal Chemistry
Carmen Burtea, Sophie Laurent, Tuba Sanli, Deborah Fanfone, Aude Devalckeneer, Sébastien Sauvage, Marie-Claire Beckers, Sandrine Rorive, Isabelle Salmon, Luce Vander Elst, Bernard R Lauwerys, Robert N Muller
BACKGROUND: Interleukin-7 receptor alpha (IL-7Rα) represents a biomarker with potential applications in rheumatoid arthritis (RA) diagnosis and therapy. We have therefore searched by phage display potential IL-7Rα specific peptides with the primary goal being to develop in vivo molecular imaging tools. METHODS: IL-7Rα-targeted peptides were searched within a disulfide-constrained combinatorial phage displayed library of random linear heptapeptides. The apparent dissociation constant (Kd) and half maximal inhibition constant (IC50) were estimated for phage clones and synthesized peptides by ELISA...
October 12, 2016: Arthritis Research & Therapy
Zaw Aung Khant, Toshinori Hirai, Yoshihito Kadota, Rie Masuda, Takanori Yano, Minako Azuma, Yukiko Suzuki, Kuniyuki Tashiro
We report a 34-year-old male who manifested T1 shortening of the cerebral cortices after more than 86 contrast-enhanced MRI studies. We observed high-signal intensity (SI) on T1-weighted images (T1WIs) not only in the globus pallidus, dentate nucleus, and pulvinar of thalamus, but also in the cortices of the pre- and post-central gyri and around the calcarine sulcus. High SI in the cerebral cortices was not clearly demonstrated on T1WI scans performed 11 years earlier. The high SI we observed in these areas of the brain corresponded to areas with a normal iron-deposition predilection...
October 11, 2016: Magnetic Resonance in Medical Sciences: MRMS
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
Simona Ghiani, Martina Capozza, Claudia Cabella, Alessandra Coppo, Luigi Miragoli, Chiara Brioschi, Roberta Bonafè, Alessandro Maiocchi
The current study was performed to evaluate the in vivo efficiency of a new nano-sized contrast agent called paramagnetic Solid Lipid Nanoparticles, pSLNs, having promising relaxivity properties for Magnetic Resonance Imaging application. Good stability and stealth properties towards macrophage uptake have been demonstrated. An in vivo MRI study resulted in an improved signal enhancement in the tumor tissue particularly when folate as targeting ligand was used to decorate the nanoparticles surface. Afterwards, the biodistribution of pSLNs in several organs was investigated...
October 5, 2016: Nanomedicine: Nanotechnology, Biology, and Medicine
J Sherwood, K Lovas, M Rich, Q Yin, K Lackey, M S Bolding, Y Bao
Recent research efforts about iron oxide nanoparticles has focused on the development of iron oxide-based T1 contrast agents for magnetic resonance imaging (MRI), such as ultrasmall iron oxide nanospheres (USNPs <4 nm) and ultrathin nanowires (NW, diameter <4 nm). In this paper, we report the cellular uptake behaviors of these two types of ultrasmall scale nanostructures on HepG2 cells. Both these two nanostructures were functionalized with tannic acid and their physical and chemical properties were carefully analyzed before cellular tests...
October 14, 2016: Nanoscale
Helene Strauch, Jörn Engelmann, Klaus Scheffler, Hermann A Mayer
A fast and simple route was developed to synthesize a new T8-silsesquioxane based contrast agent for potential application in Magnetic Resonance Imaging. For this purpose the novel C2-thiol-functionalized T8-silsesquioxane (3) was constructed as a carrier molecule as well as the DOTA based gadolinium(iii) complex (11) equipped with allyl terminated linkers was prepared. The linkage of the complexes to the T8-silsesquioxane was performed via an UV-light catalyzed thiol-ene click reaction within one hour which affords the desired product 13 in a yield of 80%...
September 27, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Daniel Shore, Sylvie L Pailloux, Jinjin Zhang, Thomas Gage, David J Flannigan, Michael Garwood, Valérie C Pierre, Bethanie J H Stadler
Electrodeposited Fe and Fe-Au nanowires were studied for potential as MRI contrast agents, especially for T2-weighted imaging. Transverse relaxivities up to r2 = 77.1 mM Fe(-1) s(-1) (at 1.5 T) were achieved when Fe-Au nanowires were coated with thiol and carboxylic acid functionalized poly(ethyleneglycol). T2-Weighted images (9 T) verified successful contrast.
October 18, 2016: Chemical Communications: Chem Comm
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