Chapter 28. Contrast Media for Magnetic Resonance Imaging

Goldstein, Harold A.; Lumma, William; Rudzik, Allan D.

doi:10.1016/s0065-7743(08)60550-3

Cited by 7 publications

(7 citation statements)

References 52 publications

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“…The imaging of internal organs and structures is an important diagnostic procedure dating back to the first medical use of X-rays. It is now quite common to use some kind of contrast agent to improve the diagnostic value of images produced by virtually all imaging modalities including X-ray, magnetic resonance (MR), − and most recently ultrasound (US) . Contrast agents aid diagnostic imaging by increasing the contrast between the specific tissue or organ of interest and surrounding tissues in the body.…”

Section: Introductionmentioning

confidence: 99%

“…Early in the development of MR it was felt that contrast agents would not be necessary, but it has become increasingly clear that in many clinical situations contrast agents can greatly improve the diagnostic value of MR, − just as they have for X-ray and CT. To be effective, MR contrast agents must have a strong local effect on the T 1 , T 2 or T 2 * relaxation times of water, have the proper pharmacokinetic properties and, obviously, be nontoxic to the patient. One of the most effective techniques for altering the relaxivity of water is to introduce a high spin paramagnetic metal such as Fe or Gd into solution.…”

Section: Introductionmentioning

confidence: 99%

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Gadolinium-Loaded Nanoparticles: New Contrast Agents for Magnetic Resonance Imaging

et al. 2000

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We have developed a new class of metal-loaded nanoparticles that have potential as contrast agents for medical imaging. These polymeric materials have a core-shell morphology where the interior is a functionalized polymer, that provides high affinity for a specific metal, and the shell consists of a porous hydrophobic polymer that modulates access to the core. In the present case, the nanoparticles are loaded with Gd 3+ to provide contrast in magnetic resonance (MR) imaging. The Gd 3+ -loaded nanoparticles described in this paper have a diameter of 120 nm and are, therefore, small enough to pass easily through the vasculature. These particles have been shown to reduce relaxation times in vitro, and provide excellent contrast when used to image the heart and gastrointestinal tract in a rat animal model.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gadolinium-Loaded Nanoparticles: New Contrast Agents for Magnetic Resonance Imaging

et al. 2000

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“…Analogous relaxation effects can be achieved with radicals, i.e. with organic species possessing one or more [15,[18][19]21,24,28,29] odd electrons, although the detailed relaxation mechanisms induced by radicals and metal ions may not be identical. The va¡ factors to be considered in the longitudinal relaxation phenomena of water proton can be pictorially presented (Fig.1), and were, in part, mathematically expressed by Solomon and Bloembergen in their equation, and by other equations [23,[36][37][38][39][40][41].…”

Section: Discussionmentioning

confidence: 99%

A numerical prediction of spin-lattice relaxation enhancement of water protons by paramagnetic metal ions and free radicals. A contribution to the basic principles of relaxometry in MRI

Sosnovsky

1992

Appl. Magn. Reson.

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The Solomon-Bloembergen and several simplified equations from literature are criticaUy evaluated with the purpose of selecting an equation for rapid numerical predictions of spin-lattice relaxation data of water protons induced by paramagnetic transition metal and lanthanide ions and organic free radicals. The following equation is proposed for practical applications:where T 1 is the spin-lattice relaxation time, 1/T 1 is the spin-lattice relaxation rate, Yz is the gyromagnetic ratio of the proton of water, 7s is the gyromagnetic ratio of the electron, k is the Boltzman constant, h is the Plank constant, h ~ h/2n, N is the number of paramagnetic species per cubic centimeter, i.e. the Avogadro number/1000, mis the concentration of the paramagnetic species in mM, r/is the viscosity in centipoise at appropriate temperature, T is the appropriate absolute temperature, S is the spin quantum number, and F is a methodical factor which can range between 1-2.7, depending on the magnetic properties of the instrumentation, i.e. -1.07 MHz (0.025 T) --90 MHz (2.1 T), and the relaxation enhancing agent. Ir is proposed to use F = 1 for rapid numerical predictions. This equation is based on models involving translational motions and is suitable for rapid estimates in vitro of spin-latfice relaxation times and rates of protons in water, and water protons in plasma and other biological fluids in the presence of paramagnetic metal ions, their low molecular weight complexes, and free radicals, as exemplified by nitroxyl (aminoxyl) radicals. Although this equation wiU be used for measurements in vitro, the results could also be applied to project the effectiveness of new contrast agents in vivo. It is believed that this equation will be useful in research involving the development of new contrast agents for MRI.

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“…When magnetic resonance imaging (MRI) was first introduced as a clinical modality in radiology, a common belief was that contrast media would seldom, if ever, be required . Although MRI was initially envisioned as a completely noninvasive technique, intravenously administered paramagnetic contrast agents (PCAs) can improve the overall quality and detail of images and allow for the unambiguous identification of pathologies that would remain otherwise undetected. − Today, over 60% of all MRI examinations employ PCAs, greatly enhancing the diagnostic specificity of MRI, as well as expanding its range of clinical applications. − …”

Section: Introductionmentioning

confidence: 99%

“…1 Although MRI was initially envisioned as a completely noninvasive technique, intravenously administered paramagnetic contrast agents (PCAs) can improve the overall quality and detail of images and allow for the unambiguous identification of pathologies that would remain otherwise undetected. [2][3][4][5][6][7][8][9] Today, over 60% of all MRI examinations employ PCAs, greatly enhancing the diagnostic specificity of MRI, as well as expanding its range of clinical applications. [10][11][12][13] PCAs based on Gd(III) possess the highest relaxivity by virtue of their large magnetic moments and large T 1e 's.…”

Section: Introductionmentioning

confidence: 99%

Structure and Energetics of Gd(III) Interactions with Water and Ammonia

Glendening

Petillo

2001

J. Phys. Chem. B

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The geometry, binding energies, and isotropic hyperfine coupling constants of Gd(III)-ligand interactions in the Gd 3+ (H 2 O) and Gd 3+ (NH 3 ) complexes have been determined by electronic structure methods. Polarized valence double-ζ and triple-ζ basis sets were developed to benchmark the properties of these complexes. Our calculations suggest that a correlated MP2 level calculation and a triple-ζ basis set are essential for quantitative treatments of the Gd(III)-ligand interaction. The combination of the uncorrelated UHF method with a double-ζ basis set is unable to accurately describe the extreme polarization of the ligands in the presence of the trivalent Gd center. Spin polarization of the ligand results in the increase of R-electron density on Gd(III).

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Chapter 28. Contrast Media for Magnetic Resonance Imaging

Cited by 7 publications

References 52 publications

Gadolinium-Loaded Nanoparticles: New Contrast Agents for Magnetic Resonance Imaging

Gadolinium-Loaded Nanoparticles: New Contrast Agents for Magnetic Resonance Imaging

A numerical prediction of spin-lattice relaxation enhancement of water protons by paramagnetic metal ions and free radicals. A contribution to the basic principles of relaxometry in MRI

Structure and Energetics of Gd(III) Interactions with Water and Ammonia

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