Determination of liver-specific r2 * of a highly monodisperse USPIO by (59) Fe iron core-labeling in mice at 3 T MRI.

摘要: Abstract Accurate determination of tissue concentration ultrasmall superparamagnetic iron oxide nanoparticles (USPIO) using T2 * MR relaxometry is still challenging. We present a reliable quantification method for local USPIO amount with the estimation liver specific relaxivity r2 monodisperse (59) Fe-core-labeled ((59) FeUSPIO). Dynamic and relaxometric in vivo characteristics unlabeled were determined MRI at 3 T. The studies performed FeUSPIO dosages 9 (n = 3), 18 (n = 2) 27 (n = 3) µmol Fe kg(-1) body weight. R2 before after injection (∆R2 *) was measured correlated activity measurements excised organs by whole radioactivity counter (HAMCO) to define dependency ∆R2 calculate liver. Ultrastructural analysis uptake histology transmission electron microscopy. revealed dosage-dependent accumulation percentage 70-88% dose. Hepatic showed dose-dependent linear correlation (r = 0.92) an 481 ± 74.9 mm(-1) s(-1) comparison vitro 60.5 ± 3.3 . Our results indicate that core-labeled can be used quantify estimate liver-specific *.