Temporal dependence of in vivo USPIO-enhanced MRI signal changes in human carotid atheromatous plaques

Tang, T. Y., Patterson, A. J., Miller, S. R., Graves, M. J., Howarth, S. P. S., U-King-Im, J. M., Li, Z. Y., Sadat, U., Young, V. E., Walsh, S. R., Boyle, J. R., Gaunt, M. E., & Gillard, J. H. (2009) Temporal dependence of in vivo USPIO-enhanced MRI signal changes in human carotid atheromatous plaques. Neuroradiology, 51(7), pp. 457-465.

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Ultrasmall superparamagnetic iron oxide (USPIO)-enhanced MRI has been shown to be a useful modality to image activated macrophages in vivo, which are principally responsible for plaque inflammation. This study determined the optimum imaging time-window to detect maximal signal change post-USPIO infusion using T1-weighted (T1w), T2- weighted (T2w) and quantitative T2(qT 2) imaging.


Six patients with an asymptomatic carotid stenosis underwent high resolution T1w, T2w and qT2MR imaging of their carotid arteries at 1.5 T. Imaging was performed before and at 24, 36, 48, 72 and 96 h after USPIO (Sinerem™, Guerbet, France) infusion. Each slice showing atherosclerotic plaque was manually segmented into quadrants and signal changes in each quadrant were fitted to an exponential power function to model the optimum time for post-infusion imaging.


The power function determining the mean time to convergence for all patients was 46, 41 and 39 h for the T1w, T 2w and qT2sequences, respectively. When modelling each patient individually, 90% of the maximum signal intensity change was observed at 36 h for three, four and six patients on T1w, T 2w and qT2, respectively. The rates of signal change decrease after this period but signal change was still evident up to 96 h.


This study showed that a suitable imaging window for T 1w, T2w and qT2signal changes post-USPIO infusion was between 36 and 48 h. Logistically, this would be convenient in bringing patients back for one post-contrast MRI, but validation is required in a larger cohort of patients.

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16 citations in Web of Science®

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ID Code: 90330
Item Type: Journal Article
Refereed: Yes
Keywords: Atherosclerosis, Carotid stenosis, Inflammation, MRI, USPIO
DOI: 10.1007/s00234-009-0523-x
ISSN: 1432-1920
Divisions: Current > Schools > School of Chemistry, Physics & Mechanical Engineering
Current > Institutes > Institute of Health and Biomedical Innovation
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Copyright Owner: Copyright 2009 Springer-Verlag
Deposited On: 16 Nov 2015 05:08
Last Modified: 11 Dec 2015 03:25

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