OBJECTIVE: We tested a new MDCT technical protocol, combining IV and intravesical positive contrast agent and intravaginal neutral contrast agent, that optimizes exploration of urogenital fistulas. We examined three patients (four CT examinations in total) with this technique and proved that a preexisting subtle ureterovaginal fistula that was under treatment ...

Here we report the design and controlled synthesis of monodisperse and precisely size-controllable UCNP@mSiO(2) nanocomposites smaller than 50 nm by directly coating a mesoporous silica shell (mSiO(2) ) on upconversion nanocrystals NaYF(4) :Tm/Yb/Gd (UCNPs), which can be used as near-infrared fluorescence and magnetic resonance imaging (MRI) agents and a platform for ...

Early inflammation following status epilepticus has been implicated in the development of epilepsy and the evolution of brain injury, yet its precise role remains unclear. The development of non-invasive imaging markers of inflammation would enable researchers to test this hypothesis in vivo and study its temporal progression in relation to ...

Magnetic moments: The orientation of the title single-molecule magnet was investigated by magnetic single crystal and luminescence characterization, supported by ab initio calculations, and was found to be governed by the position of the hydrogen atoms of the apical water molecules. This finding suggests that simple magneto-structural correlations can give ...

Magnetite (Fe(3)O(4)) - loaded polymer micelles (denoted as "magnetomicelles") are produced by self-assembly of fluorine-containing amphiphilic poly(HFMA-g-PEGMA) copolymers with oleic acid modified Fe(3)O(4) nanoparticles in an aqueous medium. The oleic acid modified Fe(3)O(4) nanoparticles form small clusters in the poly(HFMA-g-PEGMA) micelles with a mean diameter of 100 nm and the magnetomicelles ...

Noninvasive imaging studies involving small animals are becoming increasingly important in preclinical pharmacological, genetic, and biomedical cardiovascular research. Especially small animal magnetic resonance imaging (MRI) using high field and clinical MRI systems has gained significant importance in recent years. Compared to other imaging modalities, like computer tomography, MRI can provide ...

To develop an estimation method of gadolinium magnetic resonance imaging (MRI) contrast agents, the effect of concentration of Gd compounds on the ESR spectrum of nitroxyl radical was examined. A solution of either 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPONE) or 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPOL) was mixed with a solution of Gd compound and the ESR spectrum ...

Imaging of the kidney relies on three main imaging modalities: ultrasound, CT scan and MRI, on one hand, and scintigraphy, on the other hand. First intent ultrasound provides anatomic/vascular and functional information. Tissue perfusion assessment using ultrasound can be improved using contrast agents. Renal ultrasound is particularly useful but remains ...

We report a case of hepatocellular adenoma, focusing on the findings of liver-specific contrast agent-enhanced magnetic resonance imaging (MRI) and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). The patient was a 37-year-old woman, referred to us after contrast-enhanced computed tomography showed a homogeneous, poorly enhanced liver tumor, 2.8 cm in diameter. Magnetic resonance ...

Magnetic resonance imaging (MRI) contrast agents are effective tools in both medical diagnosis and life science research. Various smart contrast agents have been developed for the visualization of biological phenomena. These contrast agents have molecular switches that increase or reduce MRI signal intensity in response to the target biological reaction. ...

The Krebs tricarboxylic acid cycle (TCA) is central to metabolic energy production and is known to be altered in many disease states. Real time molecular imaging of TCA cycle <i>in</i> vivo will be important in understanding the metabolic basis of several diseases. Positron emission tomography (PET) using FDG-glucose (2-[¹⁸F]fluoro-2-deoxy-D-glucose) is ...

Various magnetic nanoparticles have been extensively investigated as novel magnetic resonance imaging (MRI) contrast agents owing to their unique characteristics, including efficient contrast effects, biocompatibility, and versatile surface functionalization capability. Nanoparticles with high relaxivity are very desirable because they would increase the accuracy of MRI. Recent progress in nanotechnology enables ...

PURPOSE: Mice are often used as small animal models of brain ischemia, venous thrombosis, or vasospasm. This article aimed at providing an overview of the currently available methodologies for in vivo imaging of the murine cerebrovasculature and comparing the capabilities and limitations of the different methods. METHODS: Micro-computed tomography angiography ...

Endometrial carcinoma is the most common gynaecological malignancy in industrialized countries. This review discusses the value of magnetic resonance imaging (MRI) and novel MRI techniques (diffusion, perfusion, spectroscopy, blood oxygen level-dependent (BOLD)-MRI, and MRI with new contrast agents) in endometrial carcinomas. Contrast-enhanced MRI is the imaging technique of choice, and ...

Magnetite/gold (Fe3O4/Au) hybrid nanoparticles were synthesized from a single iron precursor (ferric chloride) through a green chemistry route using grape seed proanthocyanidin as the reducing agent. Structural and physico-chemical characterization proved the nanohybrid to be crystalline, with spherical morphology and size ~ 35 nm. Magnetic resonance imaging and magnetization studies ...

Magnetic resonance imaging (MRI) has emerged as a leading diagnostic technique in clinical and preclinical settings. However, the application of MRI to assess specific disease markers for diagnosis and monitoring drug effect has been severely hampered by the lack of desired contrast agents with high relaxivities, and optimized in vivo ...

Magnetic iron oxide particles are widely used as contrast agents to improve the sensitivity of magnetic resonance imaging (MRI). Their efficiency in MRI is usually quantified by transverse relaxivity (r(2) ) in solution. Herein, we synthesized a series of magnetite nanocrystal clusters (MNCs) with ultra-high transverse relaxivity by a polyol ...

A great deal of effort has been made since the 1990s to enlarge the field of magnetic resonance imaging. Better tissue contrast, more biocompatible contrast agents and the absence of any radiation for the patient are some of the many advantages of using magnetic resonance imaging (MRI) rather than X-ray ...

Mesoporous silica nanospheres (MSNs) are a promising material for magnetic resonance imaging (MRI) contrast agents. In this paper multifunctional MSNs with cleavable Gd(III) chelates are synthesized and characterized, and their applicability as MRI contrast agents is demonstrated both in vitro and in vivo. The MSNs contain Gd(III) chelates that are ...

Paramagnetic and superparamagnetic metals are used as contrast materials for magnetic resonance (MR) based techniques. Lanthanide metal gadolinium (Gd) has been the most widely explored, predominant paramagnetic contrast agent until the discovery and association of the metal with nephrogenic systemic fibrosis (NSF), a rare but serious side effects in patients ...

The relaxivity (contrast-enhancing ability) of Eu(II)-containing cryptates was found to be better than a clinically approved Gd(III)-based agent at 7 T. These cryptates are among a few examples of paramagnetic substances that show an increase in longitudinal relaxivity, r(1), at ultra-high field strength relative to lower field strengths.

OBJECTIVE:To evaluate the efficacy and safety of ferumoxytol for use in magnetic resonance angiography (MRA) of the vasculature.DATA SOURCES:Literature was accessed through MEDLINE (1946-September 2011) and EMBASE (1947-September 2011) using the terms ferumoxytol,magnetic resonance imaging and angiography, blood pool agent, and superparamagnetic iron oxide. Reference citations from identified publications were ...

The purpose of this study was to assess the frequency, manifestation, and severity of acute adverse reactions associated with administration of several gadolinium-based contrast agents to patients who underwent cardiac magnetic resonance (CMR) imaging in the EuroCMR (European Cardiovascular Magnetic Resonance) Registry multinational and multicenter setting. The frequency, manifestations, and ...

The purpose of this study was to determine the influence of iodinated contrast agents on the formation of DNA double-strand breaks in vitro in lymphocytes and to verify these results in patients undergoing diagnostic computed tomography examinations. Blood samples were irradiated in vitro in the presence of iodinated X-ray contrast ...

PURPOSE: To be able to screen and identify potential candidate agents for noninvasive imaging of diseases involving angiogenesis, a standardized in vivo angiogenesis model is needed. Angiogenesis is a common feature of many pathological conditions and has become an important target for diagnosis and treatment, with many noninvasive imaging agents ...

PURPOSE: To develop safe and effective manganese(II) -based biodegradable macromolecular MRI contrast agents. MATERIALS AND METHODS: In this study, we synthesized and characterized two polydisulfide manganese(II) complexes, Mn-DTPA cystamine copolymers and Mn-EDTA cystamine copolymers, as new biodegradable macromolecular MRI contrast agents. The contrast enhancement of the two manganese-based contrast agents ...

ABSTRACT: We have developed novel gold-silver alloy nanoshells as magnetic resonance imaging (MRI) dual T1 (positive) and T2 (negative) contrast agents as an alternative to typical gadolinium (Gd)-based contrast agents. Specifically, we have doped iron oxide nanoparticles with Gd ions and sequestered the ions within the core by coating the ...

Gadolinium ion (Gd³⁺) complexes are commonly used as magnetic resonance imaging (MRI) contrast agents to enhance signals in <i>T</i>₁-weighted MR images. Recently, several methods to achieve cell-permeation of Gd³⁺ complexes have been reported, but more general and efficient methodology is needed. In this report, we describe a novel method to ...

OBJECTIVES: To develop and evaluate a procedure for quantifying the hepatocyte-specific uptake of Gd-BOPTA and Gd-EOB-DTPA using dynamic contrast-enhanced (DCE) MRI. METHODS: Ten healthy volunteers were prospectively recruited and 21 patients with suspected hepatobiliary disease were retrospectively evaluated. All subjects were examined with DCE-MRI using 0.025 mmol/kg of Gd-EOB-DTPA. The healthy ...

Progesterone receptor (PR) is strongly associated with disease prognosis and therapeutic efficacy in hormone-related diseases such as endometriosis and breast, ovarian, and uterine cancers. Receptor status is currently determined by immunohistochemistry assays. However, noninvasive PR imaging agents could improve disease detection and help elucidate pathological molecular pathways, leading to new ...

Owing largely to advances in fetal echocardiography, in most developed countries the diagnosis of severe congenital heart disease (CHD) is now made during gestation, and delivery is electively planned in hospitals that have the facilities and expertise to manage these patients, with magnetic resonance (MR) imaging performing an important complementary ...

OBJECTIVE: Ferumoxytol, an ultrasmall superparamagnetic iron oxide particle, has been suggested as a potential alternative MRI contrast agent in patients with renal failure. We compared ferumoxytol to gadoteridol enhancement on T1- and T2-weighted MRI in CNS disorders to explore its diagnostic utility. SUBJECTS AND METHODS: Data were collected from three ...

The objective of this study is to design a new multimodal imaging system for the evaluation of bone regeneration process. Pamidronate (PA) of bisphosphonates with a high affinity for hydroxyapatite, was introduced to pullulan with different molecular weights (PA-pullulan). Then, two probes for fluorescence and magnetic resonance (MR) imagings were ...

The use of gadolinium-based hepatocyte-specific contrast agents (HSCAs) has increased markedly since their introduction, and hepatocellular phase imaging performed with an HSCA is now a key part of the standard magnetic resonance (MR) imaging work-up for focal liver lesions. An understanding of the mechanisms of action of HSCAs helps ensure ...

Spherical, nonporous and monodisperse silica nanoparticles (NPs) with a diameter of about 100nm were synthesized and covalently functionalized with lanthanoid(III) (Ln=Gd or Y) chelate complexes, which serve as contrast agents (CAs) for magnetic resonance imaging (MRI). The materials were fully characterized after each synthetic step by different analytical methods, such ...

We present a magnetic resonance (MR)-guided near-infrared dynamic contrast enhanced diffuse optical tomography (DCE-DOT) system for characterization of tumors using an optical contrast agent (ICG) and a MR contrast agent [Gd-diethylenetriaminepentaacetic acid (DTPA)] in a rat model. Both ICG and Gd-DTPA are injected and monitored simultaneously using a combined MRI-DOT ...

Positive T(1) contrast using gadolinium (Gd) contrast agents can potentially improve detection of labeled cells on magnetic resonance imaging (MRI). Recently, gadolinium oxide (Gd(2)O(3)) nanoparticles have shown promise as a sensitive T(1) agent for cell labeling at clinical field strengths compared to conventional Gd chelates. The objective of this study ...

Ferumoxytol is a new product approved for intravenous use by the US Food and Drug Administration (FDA) in the treatment of iron deficiency anemia in adults with chronic kidney disease. This approval was based on data from 3 open-label, randomized, controlled clinical trials. In all of these trials, ferumoxytol was ...

Multifunctional magnetic-fluorescent nanohybrids were successfully fabricated by a facile layer-by-layer (LBL) self-assembly of in situ generated Eu, Gd co-doped LaF(3) nanocrystals (LaF(3):Eu:Gd) on the surface of multi-walled carbon nanotubes (MWNTs). Photoluminescence (PL) quenching occurred when LaF(3):Eu:Gd nanoparticles were directly coated on the surface of MWNTs. By growth of a SiO(2) ...

Purpose:To investigate the diagnostic potential of delayed contrast material-enhanced computed tomography (CT) of articular cartilage in quantification of glycosaminoglycan (GAG) concentration in normal and degenerated articular cartilage ex vivo by using a clinical CT scanner.Materials and Methods:This study was exempted by the institutional and animal review boards, and informed consent ...

Magnetic resonance imaging (MRI) studies of tissue engineered constructs prior to implantation clearly demonstrate the utility of the MRI technique for studying the bone formation process. To test the utility of our MRI protocols for explant studies, we present a novel test platform in which osteoblast-seeded scaffolds were implanted on ...

OBJECTIVE: The purpose of this work is to evaluate two signal-inducing bone cements for MRI-guided spinal cementoplasty. MATERIALS AND METHODS: The bone cements were made of polymethylmethacrylate (PMMA, 5 ml monomeric, 12 g polymeric) and gadoterate meglumine as a contrast agent (CA, 0-40 μl) with either saline solution (NaCl, 2-4 ml) or hydroxyapatite bone ...

BACKGROUND: False lumen thrombosis after aortic dissection is a major predictor of prognosis. First pass computed tomography (CT) and magnetic resonance (MR) imaging are used routinely, where the image acquisition is timed to the arrival of contrast in the proximal unaffected aorta. Delayed phase imaging is difficult to refine because ...

The goal was to optimize dynamic T1 imaging for functional MRI (fMRI) examinations. For each of the 10 healthy subjects T1 3D gradient echo sequence (GRE) sequences were provided immediately after administration of blood pool contrast agent then every 2 h when subjects performed block finger tapings. Dynamic T1 fMRI ...

The aim of this study describes the creation of superhigh-magnetization nanocarriers (SHMNCs) comprised of a magnetic Fe(3)O(4) (SHMNPs) core and a shell of aqueous stable self-doped poly[N-(1-one-butyric acid)]aniline (SPAnH), which have a high drug loading capacity (∼27.1 wt%) of doxorubicin (DOX). The SHMNCs display superparamagnetic property with a magnetization of 89.7 ...

MRI contrast agents providing very high relaxivity values can be obtained through the attachment of multiple gadolinium(III) complexes to the interior surfaces of genome-free viral capsids. In previous studies, the contrast enhancement was predicted to depend on the rigidity of the linker attaching the MRI agents to the protein surface. ...

A new method for the fabrication of Fe3O4 nanoparticles enveloped by polymeric nanocapsules is proposed. This method is characterized by combining a double emulsification with the interficial coprecipitation of iron salts to form Fe3O4/polymer composite nanocapsules in a single step. To demonstrate the viability of this approach, methoxy poly(ethylene glycol)-poly(lactide) ...

A facile one-pot synthesis of D-glucuronic acid coated ultrasmall Ln₂O₃ (Ln = Eu, Gd, Dy, Ho, and Er) nanoparticles is presented. Their water proton relaxivities were studied to address their possibility as a new potential MRI contrast agent. We focused on the D-glucuronic acid coated ultrasmall Dy₂O₃ nanoparticle because it ...

We report the development of a novel magnetic nano-contrast agent (nano-CA) based on Gd(3+) doped amorphous TiO(2) of size ∼25 nm, exhibiting enhanced longitudinal relaxivity (r(1)) and magnetic resonance (MR) contrasting together with excellent biocompatibility. Quantitative T1 mapping of phantom samples using a 1.5 T clinical MR imaging system revealed ...

MRI offers an alternative to CT, and thus is central to an ALARA strategy. However, long exam times, limited magnet availability, and motion artifacts are barriers to expanded use of MRI. This article reviews developments in pediatric body MRI that might reduce these barriers: high field systems, acceleration, navigation and ...