In vivo magnetic resonance imaging of iron oxide-labeled, arterially-injected mesenchymal stem cells in kidneys of rats with acute ischemic kidney injury: Detection and monitoring at 3T

• Published in: Journal of magnetic resonance imaging Vol. 25; no. 6; pp. 1179 - 1191
• Main Authors: Ittrich, Harald, Lange, Claudia, Tögel, Florian, Zander, Axel R., Dahnke, Hannes, Westenfelder, Christof, Adam, Gerhard, Nolte-Ernsting, Claus
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.06.2007
• Subjects: acute kidney injury; Animals; cell tracking; Contrast Media; Dextrans; Feasibility Studies; Ferrosoferric Oxide; Image Processing, Computer-Assisted; Injections, Intra-Arterial; Iron; iron oxide particles; Ischemia - diagnosis; Ischemia - physiopathology; Ischemia - therapy; Kidney - cytology; Magnetic Resonance Imaging - methods; Magnetite Nanoparticles; Mesenchymal Stem Cell Transplantation; mesenchymal stem cells; MRI; Oxides; Rats; Rats, Sprague-Dawley; Staining and Labeling
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.20925

Purpose To evaluate MRI for a qualitative and quantitative in vivo tracking of intraaortal injected iron oxide–labeled mesenchymal stem cells (MSC) into rats with acute kidney injury (AKI). Materials and Methods In vitro MRI and R2* measurement of nonlabeled and superparamagnetic iron oxide (SPIO)‐labeled MSC (MSCSPIO) was performed in correlation to cellular iron content and cytological examination (Prussian blue, electron microscopy). In vivo MRI and R2* evaluation were performed before and after ischemic/reperfusion AKI (N = 14) and intraaortal injection of 1.5 × 106 MSCSPIO (N = 7), fetal calf serum (FCS) (medium, N = 6), and SPIO alone (N = 1) up to 14 days using a clinical 3T scanner. Signal to noise ratios (SNR), R2* of kidneys, liver, spleen, and bone marrow, renal function (creatinine [CREA], blood urea nitrogen [BUN]), and kidney volume were measured and tested for statistical significance (Student's t‐test, P < 0.05) in comparison histology (hematoxylin and eosin [H&E], Prussian blue, periodic acid‐Schiff [PAS], CD68). Results In vitro, MSCSPIO showed a reduction of SNR and T2* with R2* ≈ number of MSCSPIO (R2 = 0.98). In vivo MSCSPIO administration resulted in a SNR decrease (35 ± 15%) and R2* increase (101 ± 18.3%) in renal cortex caused by MSCSPIO accumulation in contrast to control animals (P < 0.01). Liver, spleen, and bone marrow (MSCSPIO) showed a delayed SNR decline/R2* increase (P < 0.05) resulting from MSCSPIO migration. The increase of kidney volume and the decrease in renal function (P < 0.05) was reduced in MSC‐treated animals. Conclusion Qualitative and quantitative in vivo cell‐tracking and monitoring of organ distribution of intraaortal injected MSCSPIO in AKI is feasible in MRI at 3T. J. Magn. Reson. Imaging 2007;25:1179–1191. © 2007 Wiley‐Liss, Inc.