Superparamagnetic iron oxide: enhanced detection of focal splenic tumors with MR imaging.

Weissleder, Ralph; Hahn, P F; Stark, David D.; Elizondo, Guillermo; Saini, S; Todd, Luis E.; Wittenberg, J; Ferrucci, J T

doi:10.1148/radiology.169.2.3174987

Cited by 130 publications

(55 citation statements)

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“…117,133,149 In addition to the detection and characterization of liver lesions, larger nanoparticles such as SHU555A and AMI-25 have also been shown capable of detecting focal splenic tumors. 5,157,160 Reimer et al, in imaging hepatic lesions, clearly show the power of enhanced detection through the use of SPIO, 117 ( Fig. 1).…”

Section: Liver and Splenic Imagingmentioning

confidence: 91%

Superparamagnetic Iron Oxide Nanoparticle Probes for Molecular Imaging

et al. 2006

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Abstract-The field of molecular imaging has recently seen rapid advances in the development of novel contrast agents and the implementation of insightful approaches to monitor biological processes non-invasively. In particular, superparamagnetic iron oxide nanoparticles (SPIO) have demonstrated their utility as an important tool for enhancing magnetic resonance contrast, allowing researchers to monitor not only anatomical changes, but physiological and molecular changes as well. Applications have ranged from detecting inflammatory diseases via the accumulation of non-targeted SPIO in infiltrating macrophages to the specific identification of cell surface markers expressed on tumors. In this article, we attempt to illustrate the broad utility of SPIO in molecular imaging, including some of the recent developments, such as the transformation of SPIO into an activatable probe termed the magnetic relaxation switch.

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Section: Liver and Splenic Imagingmentioning

confidence: 91%

Superparamagnetic Iron Oxide Nanoparticle Probes for Molecular Imaging

et al. 2006

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“…MR detection of cells in vivo is often accomplished following labeling with superparamagnetic iron oxide (SPIO) particles. SPIO are negative contrast agents that are typically composed of an iron oxide crystal core surrounded by a polymer or polysaccharide shell [15]. A variety of manifestations of SPIO have been used to track cells, which can be broadly categorized as 1) Ultrasmall-SPIO (USPIO) with an overall diameter of 30-50 nm [16], 2) Standard-SPIO (SSPIO) with a diameter of 50-150 nm and 3) Micron-sized paramagnetic iron oxide (MPIO) having a diameter approaching or greater than 1 μm [17].…”

Section: Introductionmentioning

confidence: 99%

Size, charge and concentration dependent uptake of iron oxide particles by non-phagocytic cells

2008

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A promising new direction for contrast-enhanced magnetic resonance (MR) imaging involves tracking the migration and biodistribution of superparamagnetic iron oxide (SPIO)-labeled cells in vivo. Despite the large number of cell labeling studies that have been performed with SPIO particles of differing size and surface charge, it remains unclear which SPIO configuration provides optimal contrast in non-phagocytic cells. This is largely because contradictory findings have stemmed from the variability and imprecise control over surface charge, the general need and complexity of transfection and/or targeting agents, and the limited number of particle configurations examined in any given study. In the present study, we systematically evaluated the cellular uptake of SPIO in non-phagocytic T cells over a continuum of particle sizes ranging from 33 nm to nearly 1.5 μm, with precisely controlled surface properties, and without the need for transfection agents. SPIO labeling of T cells was analyzed by flow cytometry and contrast enhancement was determined by relaxometry. SPIO uptake was dose dependent and exhibited sigmoidal charge dependence, which was shown to saturate at different levels of functionalization. Efficient labeling of cells was observed for particles up to 300nm, however micron-sized particle uptake was limited. Our results show that an unconventional highly cationic particle configuration at 107 nm maximized MR contrast of T cells, outperforming the widely utilized USPIO (<50 nm).

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“…The SPIOs include standard SPIOs (size, usually 50-150 nm), USPIOs (size, 30-50 nm) [67] and micron-sized paramagnetic iron oxide (MPIO) (size, approaching or more than 1 μm) [68]. The first use of SPIOs as a contrast agent was in liver and splenic tumor imaging [69,70]. As a cellular label, SPIOs are used for MR cell tracking, as in detecting the specific locations of inflammation [71] or macrophage infiltration [72] in experimental autoimmune encephalomyelitis (EAE), the most widely used murine model of MS.…”

Section: Fig 5 Cd8mentioning

confidence: 99%

MRI in Rodent Models of Brain Disorders

et al. 2011

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Summary: Magnetic resonance imaging (MRI) is a wellestablished tool in clinical practice and research on human neurological disorders. Translational MRI research utilizing rodent models of central nervous system (CNS) diseases is becoming popular with the increased availability of dedicated small animal MRI systems. Projects utilizing this technology typically fall into one of two categories: 1) true "pre-clinical" studies involving the use of MRI as a noninvasive disease monitoring tool which serves as a biomarker for selected aspects of the disease and 2) studies investigating the pathomechanism of known human MRI findings in CNS disease models. Most small animal MRI systems operate at 4.7-11.7 Tesla field strengths. Although the higher field strength clearly results in a higher signalto-noise ratio, which enables higher resolution acquisition, a variety of artifacts and limitations related to the specific absorption rate represent significant challenges in these experiments. In addition to standard T1-, T2-, and T2*-weighted MRI methods, all of the currently available advanced MRI techniques have been utilized in experimental animals, including diffusion, perfusion, and susceptibility weighted imaging, functional magnetic resonance imaging, chemical shift imaging, heteronuclear imaging, and 1 H or 31 P MR spectroscopy. Selected MRI techniques are also exclusively utilized in experimental research, including manganese-enhanced MRI, and cell-specific/molecular imaging techniques utilizing negative contrast materials. In this review, we describe technical and practical aspects of small animal MRI and provide examples of different MRI techniques in anatomical imaging and tract tracing as well as several models of neurological disorders, including inflammatory, neurodegenerative, vascular, and traumatic brain and spinal cord injury models, and neoplastic diseases.

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Superparamagnetic iron oxide: enhanced detection of focal splenic tumors with MR imaging.

Cited by 130 publications

References 0 publications

Superparamagnetic Iron Oxide Nanoparticle Probes for Molecular Imaging

Superparamagnetic Iron Oxide Nanoparticle Probes for Molecular Imaging

Size, charge and concentration dependent uptake of iron oxide particles by non-phagocytic cells

MRI in Rodent Models of Brain Disorders

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