Introduction Single injection moving table peripheral contrast enhanced MR angiography is increasingly utilized for the evaluation of peripheral atherosclerotic occlusive disease (PAOD). Peripheral MRA (pMRA) is typically performed using a moving table technique during first passage of double to triple dose (0.2-0.3 mmol/kg) extracellular gadolinium chelate. The objective of this study was to c...

We introduce a mechanism for ion sensing by MRI in which analytes compete with paramagnetic ions for binding to polydentate chelating agents. Displacement of the paramagnetic ions results in alteration of solvent interaction parameters and consequent changes in relaxivity and MRI contrast. The MRI changes can be tuned by the choice of chelator. As an example, we show that calcium-dependent disp...

An efficient magnetic resonance imaging (MRI) contrast agent with a high R2 relaxivity value is achieved by controlling the shape of iron oxide to rod like morphology with a length of 30-70 nm and diameter of 4-12 nm. Fe3O4 nanorods of 70 nm length, encapsulated with polyethyleneimine show a very high R2 relaxivity value of 608 mM(-1) s(-1). The enhanced MRI contrast of nanorods is attributed t...

The incorporation of a rigid cyclobutane spacer into the EDTA scaffold impacts relaxivity, water exchange kinetics and stability Mn2+ complex.

MnO nanoparticles have been tested to engineer a delayed increase in MRI T(1) relaxivity caused by cellular uptake via endocytosis into acidic compartments. Various coatings on core-shell structured MnO nanoparticles were tested for those that had the lowest T(1) relaxivity at pH 7.4, a pH where MnO does not dissolve into Mn(2+) ions. The rate of dissolution and release of Mn(2+) of the differe...

Magnetic resonance imaging contrast agents are currently designed by modifying their structural and physiochemical properties to improve relaxivity and to enhance image contrast. Here, we show a general method for increasing relaxivity by confining contrast agents inside the nanoporous structure of silicon particles. Magnevist, gadofullerenes and gadonanotubes were loaded inside the pores of qu...

Water-soluble poly(allylamine) Mn2+-doped Si (SiMn) nanoparticles (NPs) were prepared and show promise for biologically related applications. The nanoparticles show both strong photoluminescence and good magnetic resonance contrast imaging. The morphology and average diameter were obtained through transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM...

Paramagnetic nanomaterials for use as magnetic resonance imaging (MRI) contrast agents have higher relaxivity than conventional low molecular weight MRI agents. However, the biocompatibility and pharmacokinetics of such nanomaterials will strongly affect the likelihood of clinical approval. We synthesized MRI contrast agents based on biocompatible lysine-dendri-grafts: Gd-BzDTPA-lysineG2 and Gd...

RATIONALE AND OBJECTIVES To characterize and compare commercially available contrast media (CM) for magnetic resonance imaging (MRI) in terms of their relaxivity at magnetic field strengths ranging from 0.47 T to 4.7 T at physiological temperatures in water and in plasma. Relaxivities also were quantified in whole blood at 1.5 T. METHODS Relaxivities of MRI-CM were determined by nuclear magne...

Responsive magnetic resonance imaging (MRI) contrast agents, those that change their relaxivity according to environmental stimuli, have promise as next generation imaging probes in medicine. While several of these are known based on covalent modification of the contrast agents, fewer are known based on controlling non-covalent interactions. We demonstrate here accentuated relaxivity of a T1-sh...