Premium
Polystyrene microsphere–ferritin conjugates: A robust phantom for correlation of relaxivity and size distribution
Author(s) -
Sukerkar Preeti A.,
Rezvi Uzma G.,
MacRenaris Keith W.,
Patel Pinal C.,
Wood John C.,
Meade Thomas J.
Publication year - 2011
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.22627
Subject(s) - imaging phantom , polystyrene , microsphere , conjugate , ferritin , distribution (mathematics) , materials science , nuclear magnetic resonance , biomedical engineering , chemistry , nuclear medicine , mathematics , physics , polymer , medicine , chemical engineering , engineering , mathematical analysis , biochemistry
In vivo iron load must be monitored to prevent complications from iron overload diseases such as hemochromatosis or transfusion‐dependent anemias. While liver biopsy is the gold standard for determining in vivo iron load, MRI offers a noninvasive approach. MR phantoms have been reported that estimate iron concentration in the liver and mimic relaxation characteristics of in vivo deposits of hemosiderin. None of these phantoms take into account the size distribution of hemosiderin, which varies from patient to patient based on iron load. We synthesized stable and reproducible microsphere‐ferritin conjugates (ferribeads) of different sizes that are easily characterized for several parameters that are necessary for modeling such as iron content and bead fraction. T 1 s and T 2 s were measured on a 1.41‐T low‐resolution NMR spectrometer and followed a size‐dependent trend. Ferribeads imaged at 4.7 and 14.1 T showed that signal intensities are dependent on the distribution of ferritin around the bead rather than the iron concentration alone. These particles can be used to study the effects of particle size, ferritin distribution, and bead fraction on proton relaxation and may be of use in mimicking hemosiderin in a phantom for estimating iron concentration. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.