OBJECTIVE. Iodinated contrast agent for CT has a short half-life in the vasculature. As the field of interventional procedures expands, a more durable contrast agent would be highly useful. Our study investigated whether gold nanoparticles are feasible as a long-lasting vascular contrast agent for CT. MATERIALS AND METHODS. Gold nanoparticles ...

OBJECTIVE: Dynamic contrast-enhanced computed tomography (CT) is a sensitive method to evaluate functional changes of the tumor microvasculature after antitumor therapy by monitoring the kinetics of the contrast agent (CA) passage. Therefore, the pharmacokinetic properties of the CA possess a central role: iodinated x-ray CAs are small molecules that distribute ...

Amyloid plaques are one of the major microscopic lesions that characterize Alzheimer's disease. Current approaches to detect amyloid plaques by using magnetic resonance imaging (MRI) contrast agents require invasive procedures to penetrate the blood-brain barrier (BBB) and to deliver the contrast agent into the vicinity of amyloid plaques. Here we ...

PURPOSE: CatalyCEST MRI compares the detection of an enzyme-responsive chemical exchange saturation transfer (CEST) agent with the detection of an unresponsive "control" CEST agent that accounts for other conditions that influence CEST. The purpose of this study was to investigate the feasibility of in vivo catalyCEST MRI. METHODS: CEST agents ...

Macromolecular Gd(III)-based contrast agents are effective for contrast-enhanced blood pool and cancer MRI in preclinical studies. However, their clinical applications are impeded by potential safety concerns associated with slow excretion and prolonged retention of these agents in the body. To minimize the safety concerns of macromolecular Gd contrast agents, we ...

The clinical potentials of radiotherapy could not be achieved completely because of the inaccurate positioning and inherent radioresistance of tumours. In this study, a novel active-targeting upconversion theranostic agent (arginine-glycine-aspartic acid-labelled BaYbF5: 2% Er(3+) nanocube) was developed for the first time to address these clinical demands. Heavy metal-based nanocubes (~10 nm) ...

OBJECTIVES: To determine whether positive oral contrast agents improve accuracy of abdominopelvic CT compared with no, neutral or negative oral contrast agent. METHODS: Literature was searched for studies evaluating the diagnostic performance of abdominopelvic CT with positive oral contrast agents against imaging with no, neutral or negative oral contrast agent. ...

Polysilsesquioxane (PSQ) nanoparticles are crosslinked homopolymers formed by condensation of functionalized trialkoxysilanes, and provide an interesting platform for developing biologically and biomedically relevant nanomaterials. In this work, the design and synthesis of biodegradable PSQ particles with extremely high payloads of paramagnetic Gd(III) centers is explored, for use as efficient contrast ...

Optical coherence tomography (OCT) has revolutionised clinical ophthalmology. The translation of OCT into the operating room is a natural next step given its high-resolution anatomic information. Contrast agents and enhancement have significantly improved the diagnostic capabilities of numerous imaging modalities (such as CT and MRI). The use of OCT contrast ...

Gd in silica: Noncovalent confinement of a monoaqua Gd chelate into biocompatible silica nanoparticles (NPs; see figure) by a sol-gel method affords a new example of nanosized contrast agents with very high per-Gd relaxivities. Such NPs provide a route to highly efficient multimodal contrast agents.

Gadolinium (Gd) chelate contrast-enhanced magnetic resonance imaging (MRI) is a preferred method of glioma detection and preoperative localisation because it offers high spatial resolution and non-invasive deep tissue penetration. Gd-based contrast agents, such as Gd-diethyltriaminepentaacetic acid (DTPA-Gd, Magnevist), are widely used clinically for tumor diagnosis. However, the Gd-based MRI approach ...

Computed tomography (CT) is one of the most widely used clinical imaging modalities. In order to increase the sensitivity of CT, small iodinated compounds are used as injectable contrast agents. However, the iodinated contrast agents are excreted through the kidney and have short circulation times. This rapid renal clearance not ...

This review focuses on the current evidence available on the use of single-photon emission computed tomography-computed tomography (SPECT-CT) in infection imaging. The single-photon functional agents commonly used to image infection include In-111-labelled or Tc-99m-labelled leucocytes, Ga-67 citrate, Tc-99m-biphosphonates and radiolabelled antigranulocyte antibodies. Although many of these agents have been available ...

Liver is a common site for distal metastases in colon and rectal cancer. Numerous clinical studies have analyzed the relative merits of different imaging modalities for detection of liver metastases. Several exciting new therapies are being investigated in preclinical models. But, technical challenges in preclinical imaging make it difficult to ...

Contrast-enhanced magnetic resonance angiography is a reliable way to assess peripheral vascular disease. This article reviews the basic physics behind this technique and discusses our institution's experience with regard to the clinical role, recent advances in image acquisition and use of contrast agents. Problems that can affect image quality and ...

OBJECTIVE. The purpose of this study was to use measured glomerular filtration rate (GFR), the reference standard of renal function, to assess the deleterious effect of iodinated contrast media on renal function. Such an effect has been traditionally defined as a greater than 0.5-mg/dL increase in serum creatinine concentration or ...

Instruments that combine positron emission tomography (PET) and magnetic resonance (MR) imaging have recently been assembled for use in humans, and may have diagnostic performance superior to that of PET/computed tomography (CT) for particular clinical and research applications. MR imaging has major strengths compared with CT, including superior soft-tissue contrast ...

Purpose:To develop a technique with clinical 3.0-T magnetic resonance (MR) imaging to delineate local contrast agent distribution in coronary artery walls for potential molecular MR imaging-guided local gene or drug therapy of atherosclerotic coronary artery disease.Materials and methods:This animal protocol was approved by the institutional animal care and use committee ...

PURPOSE: The aim of this study was to perform the detection of folate receptor (FR)-positive tumors with a bimodal imaging contrast agent, a perfluorocarbon (PFC)/rhodamine nanoemulsion, providing both (19)F-based magnetic resonance imaging (MRI) and fluorescence imaging capabilities. PROCEDURES: The PFC/rhodamine nanoemulsion was further infused with phospholipid-anchored folate to improve the ...

BACKGROUND: To evaluate the contrast agent performance of Gd-EOB-DTPA and Gd-BOPTA for detection and assessment of extrahepatic findings, semi-quantitatively and qualitatively. METHODS: 13 patients with 19 extrahepatic lesions underwent liver MRI with Gd-EOB-DTPA and Gd-BOPTA. Quantitative and relative SNR measurements were performed in each dataset in the arterial and portalvenous ...

Currently there are no approved biomarkers for the pre-symptomatic diagnosis of Alzheimer's disease (AD). Cathepsin-D (Cat-D) is a lysosomal protease that is present at elevated levels in amyloid plaques and neurons in patients with AD and is also elevated in some cancers. We have developed a magnetic resonance imaging (MRI)/fluorescent ...

Newer hepatobiliary magnetic resonance (MR) contrast agents allow the ability to combine the anatomical information from T2-weighted magnetic resonance cholangiopancreatography with functional information derived from contrast-enhanced T1-weighted magnetic resonance cholangiography for off-label biliary imaging. Potential applications include determination of biliary anatomy, functional assessment of biliary obstruction, and evaluation for acute ...

This review focuses on MRI contrast agents for tumor diagnosis. Several types of low molecular weight Gd3+-based complexes and dextran-coated superparamagnetic iron oxide (SPIO) nanoparticles have been used for clinical tumor diagnosis as longitudinal relaxation time (T1) and transverse relaxation time (T2) MRI contrast agents, respectively. To further improve the ...

Recent advances in molecular resonance imaging of atherosclerosis enable to visualize atherosclerotic plaques in vivo using molecular targeted contrast agents. This offers opportunities to study atherosclerosis development and plaque vulnerability noninvasively. In this review, we discuss MRI contrast agents targeted toward atherosclerotic plaques and illustrate how these new imaging platforms ...

We compared the enhancement effect between a newly synthesized tissue-specific contrast agent, [Gd-DOTA-FPβG], and a commercially available agent, [Gd(DOTA)](-), in a murine model of liver tumor using a clinical magnetic resonance imaging scanner. The colon cancer cell lines with and without β-glucuronidase (βG) expression were implanted into the liver of ...

PURPOSE: Magnetic resonance imaging (MRI) with targeted contrast agents provides a promising means for diagnosis and treatment monitoring after cerebrovascular injury. Our goal was to demonstrate the feasibility of this approach to detect the neuroinflammatory biomarker intercellular adhesion molecule-1 (ICAM-1) after stroke and to establish a most efficient imaging procedure. ...

Magnetic resonance imaging (MRI) contrast agents have been used routinely for more than 20 years in order to increase sensitivity and specificity of lesion detection. MRI contrast agents (CAs) are usually categorized according to their magnetic behavior, biodistribution, and effect on the MR image. Typically, small molecular-weight gadolinium based CAs ...

X-ray computed tomography (CT), an efficient non-invasive clinical technique, usually provides high-resolution 3D structure details of tissues in early disease diagnosis. Here, we report a high-performance CT imaging platform based on a monodispersed Yb-based nanoparticulate contrast agent. The well-prepared nanoprobes presented excellent in vitro and in vivo performances in the ...

Potentials of hydrophilic and biocompatible ligand coated gadolinium oxide nanoparticles as multimodal imaging agents, drug carriers, and therapeutic agents are reviewed. First of all, they can be used as advanced T1 magnetic resonance imaging (MRI) contrast agents because they have r1 larger than those of Gd(III)-chelates due to a high ...

As we move towards an era of personalized medicine, molecular imaging contrast agents are likely to see an increasing presence in routine clinical practice. Magnetic resonance (MR) imaging has garnered particular interest as a platform for molecular imaging applications due its ability to monitor anatomical changes concomitant with physiologic and ...

Hepatocyte-specific contrast agents have been made available in the last 15 years for magnetic resonance imaging of the liver. These agents are differentially taken up by functioning hepatocytes and excreted in the biliary system. They can help distinguish focal liver lesions of hepatocellular origin from lesions of nonhepatocellular origin, and ...

Metalloproteins have long been recognized as key determinants of endogenous contrast in magnetic resonance imaging (MRI) of biological subjects. More recently, both natural and engineered metalloproteins have been harnessed as biotechnological tools to probe gene expression, enzyme activity, and analyte concentrations by MRI. Metalloprotein MRI probes are paramagnetic and function ...

Deuterium oxide (D(2) O), which is commercially available and nonradioactive, was proposed as a perfusion tracer before the clinical usage of conventional gadolinium-based MRI contrast agents. However, the sensitivity of direct deuterium detection is the major challenge for its application. In this study, we propose a contrast-enhanced strategy to indirectly ...

PURPOSE: To compare the influence of two different upper limb positions on contrast agent effects in chest CT enhancement. MATERIALS AND METHODS: In 142 patients undergoing contrast-enhanced CT chest scanning, an indwelling venous catheter was placed in the right hand and iodinated contrast agent was injected through a high-pressure single ...

The clinical need for characterising small renal masses (SRMs) is increasing due to their rising incidental detection. This increase is especially seen in younger and older generations and concerns mainly SRMs. Diagnostics is mainly made by contrast-enhanced CT or MRI. However, these imaging methods fail to accurately distinguishing benign from ...

Magnetic resonance imaging (MRI) of disease biomarkers, especially cancer biomarkers, could potentially improve our understanding of the disease and drug activity during preclinical and clinical drug treatment and patient stratification. MRI contrast agents with high relaxivity and targeting capability to tumor biomarkers are highly required. Extensive work has been done ...

Reducing ferromagnetic particle size is an important strategy to improve their positive effect on image through the suppression of their negative effect, demonstrated by ultrasmall manganese ferrite nanoparticles prepared from an environmentally-friendly aqueous route. These ultrasmall particles exhibit pronounced paramagnetic characteristics and nontoxicity, making them efficient T(1) -positive contrast agent ...

Objective-To assess the feasibility and usefulness of CT enterography to evaluate the gastrointestinal tract in clinically normal llamas and alpacas. Design-Prospective observational study. Animals-7 clinically normal alpacas and 8 clinically normal llamas. Procedures-The imaging protocol included orogastric administration of iodinated contrast material mixed with water. Three hours later, helical CT ...

BackgroundMultimodal contrast agents usually containing two or more signal components can be used for several imaging modalities. Thus, complimentary information can be obtained by using just one kind of contrast agents.PurposeTo investigate the potential of superparamagnetic perfluorooctylbromide nanoparticles (M-PFOBNP) as a multimodal contrast agent for ultrasonography (US)/magnetic resonance (MR)/computed tomography ...

Three magnetic resonance (MR)/fluorescence imaging probes were tested for visualization, cellular distribution, and survival of labeled pancreatic islets in vitro and following transplantation. As T(1) contrast agents (CAs), gadolinium(III) complexes linked to β-cyclodextrin (Gd-F-βCD) or bound to titanium dioxide (TiO(2) @RhdGd) were tested. As a T(2) CA, perovskite manganite nanoparticles (LSMO@siF@si) ...

OBJECTIVES: Assessment of contrast agent kinetics in contrast-enhanced MRI (CE-MRI) with gadolinium-containing contrast agents offers the opportunity to predict breast lesion malignancy. The goal of our study was to determine if similar patterns exist for spectral contrast-enhanced digital breast tomosynthesis (CE-DBT) using an iodinated contrast agent. METHODS: The protocol of ...

Multiple sclerosis lesions or plaques are considered to be the result of an inflammatory process in the brain that leads to attack myelin. Inflammation causes disruption of blood-brain barrier in acute, active plaque areas. This process may lead to increase blood supply that causes increase in temperature in these associated ...

The use of contrast-enhanced MRI to enable in vivo specific characterization of atherosclerotic plaques is increasing. In this study the intrinsic ability of two differently sized gadolinium-based contrast agents to enhance atherosclerotic plaques in ApoE(-/-) mice was evaluated with MRI. We obtained a kinetic profile for contrast enhancement, as the ...

Magnetic resonance imaging (MRI) is a key imaging modality in cancer diagnostics and therapy monitoring. MRI-based tumor detection and characterization is commonly achieved by exploiting the compositional, metabolic, cellular, and vascular differences between malignant and healthy tissue. Contrast agents are frequently applied to enhance this contrast. The last decade has ...

To compare the efficacy and patients' tolerance of a new mixed biphasic oral contrast solution with routine biphasic oral contrast agent in magnetic resonance (MR) enterography (MRE). Thirty-seven patients (group 1) had MRE with the new mixture, whereas 14 patients (group 2) had MRE with biphasic oral contrast agent (lactulose). ...

The knowledge of brain tissues characteristics (such as extracellular space and tortuosity) represents valuable information for the design of optimal MR probes for specific biomarkers targeting. This work proposes a methodology based on dynamic acquisition of relaxation time maps to quantify in vivo MRI contrast agent concentration after intra-cerebral injection ...

The molecular processes underlying carcinogenesis and malignant spread are the foundation of future drug development for the treatment of cancer. Understanding these processes requires study of the interaction of complex biologic systems in a way that spatially and temporally recapitulates that seen in humans. Likewise, once an anticancer agent is ...

Transjugular intrahepatic portosystemic shunt (TIPS) has become an important and effective interventional procedure in treatment of the complications related to portal hypertension. Although the primary patency of TIPS has been greatly improved due to the clinical application of cover stent-grafts, the long-term patency is still suboptimal. This study was to ...

Increasing hepatobiliary laparoscopic surgeries have lead to a rise in injury to the biliary tree and other complications like bile leak. Ultrasonography (US) and computed tomography (CT) cannot reliably distinguish bile from other postoperative fluid collections. Magnetic resonance (MR) imaging with hepatobiliary agents and MR cholangiopancreatography provide anatomic and functional ...

A novel synthetic methodology for preparing amide conjugates of the DO3A-N-(α-amino)propionate chelator is described, using the synthesis of the DO3A-N-(α-benzoylamido)propionate chelator as an illustrative example. The model Gd[DO3A-N-(α-benzoylamido)propionate] chelate displays accelerated water exchange, stability in a wide pH range and inertness towards transmetallation by Zn(2+) . The Gd[DO3A-N-(α-benzoylamido)propionate] complex is ...