Automated detection and characterization of SPIO-labeled cells and capsules using magnetic field perturbations
Article first published online: 7 JUN 2011
Copyright © 2011 Wiley-Liss, Inc.
Magnetic Resonance in Medicine
Volume 67, Issue 1, pages 278–289, January 2012
How to Cite
Mills, P. H., Hitchens, T. K., Foley, L. M., Link, T., Ye, Q., Weiss, C. R., Thompson, J. D., Gilson, W. D., Arepally, A., Melick, J. A., Kochanek, P. M., Ho, C., Bulte, J. W. M. and Ahrens, E. T. (2012), Automated detection and characterization of SPIO-labeled cells and capsules using magnetic field perturbations. Magn Reson Med, 67: 278–289. doi: 10.1002/mrm.22998
- Issue published online: 21 DEC 2011
- Article first published online: 7 JUN 2011
- Manuscript Accepted: 16 APR 2011
- Manuscript Revised: 15 APR 2011
- Manuscript Received: 8 NOV 2010
- National Institutes of Health. Grant Numbers: R01-EB005740, R01-CA134633, R01-EB003453, R01-HL081349, R01-EB007825, P41-EB001977
- magnetic moment;
- cell tracking;
Understanding how individual cells behave inside living systems will help enable new diagnostic tools and cellular therapies. Superparamagnetic iron oxide particles can be used to label cells and theranostic capsules for noninvasive tracking using MRI. Contrast changes from superparamagnetic iron oxide are often subtle relative to intrinsic sources of contrast, presenting a detection challenge. Here, we describe a versatile postprocessing method, called Phase map cross-correlation Detection and Quantification (PDQ), that automatically identifies localized deposits of superparamagnetic iron oxide, estimating their volume magnetic susceptibility and magnetic moment. To demonstrate applicability, PDQ was used to detect and characterize superparamagnetic iron oxide-labeled magnetocapsules implanted in porcine liver and suspended in agarose gel. PDQ was also applied to mouse brains infiltrated by MPIO-labeled macrophages following traumatic brain injury; longitudinal, in vivo studies tracked individual MPIO clusters over 3 days, and tracked clusters were corroborated in ex vivo brain scans. Additionally, we applied PDQ to rat hearts infiltrated by MPIO-labeled macrophages in a transplant model of organ rejection. PDQ magnetic measurements were signal-to-noise ratio invariant for images with signal-to-noise ratio > 11. PDQ can be used with conventional gradient-echo pulse sequences, requiring no extra scan time. The method is useful for visualizing biodistribution of cells and theranostic magnetocapsules and for measuring their relative iron content. Magn Reson Med, 2011. © 2011 Wiley-Liss, Inc.