RES-specific imaging of the liver and spleen with iron oxide particles designed for blood pool MR-angiography
✍ Scribed by Christoph Bremer; Thomas Allkemper; Joerg Baermig; Peter Reimer
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 361 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1053-1807
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✦ Synopsis
The purpose of this study was to determine the dependency of liver-and spleen-enhancement on particle size and dose of bolus-injectable iron oxides designed for bloodpool MR-angiography (MRA). The superparamagnetic iron oxide SHU 555 A [particle size 65 nm (group 1)] and three derivatives designed for blood-pool MRA (groups 2-4) with smaller hydrodynamic diameters (46/33/21 nm) were i.v. injected in New Zealand White rabbits at doses of 10, 20, or 40 mol Fe/kg bw. MRI was performed before, 2, and 24 hours after contrast application using T1-weighted SE and T2-weighted TSE sequences. In addition splenic tissue was harvested post mortem and scanned ex vivo. All iron oxides significantly decreased the SI of liver and spleen in T1-and T2-weighted images at 2 and 24 hours after application of contrast media (P F 0.01). The signal intensity was inversely related to the dose applied. Decreasing particle size resulted in a lower signal enhancement in liver and spleen. However, ultra-small superparamagnetic iron oxides suited for blood-pool MRA (USPIOs, group 4) still revealed a significant signal enhancement in the liver and spleen even 24 hours after contrast application (F ؊ 60%, 40 mol Fe/kg bw). They might thus be used for comprehensive abdominal studies including contrast enhanced MR-angiography and RES-specific imaging.