Superparamagnetic iron oxide: clinical time-response study.
Eur J Radiol
; 12(3): 195-200, 1991.
Article
em En
| MEDLINE
| ID: mdl-1649755
ABSTRACT
Superparamagnetic iron oxide (AMI 25) is a promising new contrast agent for imaging the reticuloendothelial-system. Iron oxide crystals possess a large magnetic susceptibility and enhance proton relaxation rates, especially transverse relaxation (T2). In order to guide the clinical utilization of this contrast media we analyzed 4 patients with malignant lesions of the liver before and after slow intravenous administration (20 mumol Fe/kg) of AMI 25. We performed two magnetic resonance (MR) sequences at different times using a 0.35 T magnet. MR signal-to-noise ratio (SNR) of the reticuloendothelial system (particularly the liver SNR) decrease promptly. The maximum decrease in SNR (67-72% for the liver, 46-65% for the spleen, 23-41% for the bone marrow) is observed 3 h after injection (P less than 0.01). However, except the peak of contrast enhancement in T1-weighted sequences of splenic tissue, the curve describes a plateau within 30 min and 6 h, allowing a delay between injection and imaging. T2-weighted sequences give a greater contrast-to-noise ratio (CNR) by adding the spontaneous tumor contrast to the effect yielded by AMI 25. These results suggest that images must be acquired between 1 and 6 h after intravenous administration of superparamagnetic iron oxide.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Óxidos
/
Sistema Fagocitário Mononuclear
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Imageamento por Ressonância Magnética
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Meios de Contraste
/
Ferro
Limite:
Aged
/
Humans
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Male
/
Middle aged
Idioma:
En
Revista:
Eur J Radiol
Ano de publicação:
1991
Tipo de documento:
Article
País de afiliação:
França