MRI Relaxometry for Quantitative Analysis of USPIO Uptake in Cerebral Small Vessel Disease

International Journal of Molecular Sciences

Alex Vesey¹  Gordon W. Blair²  Maria C. Valdes-Hernandez²  Andreas Glatz²  Ian Marshall²  Michael J. Thrippleton²  Fergus Doubal²  Joanna M. Wardlaw²  Scott I. K. Semple³  David E. Newby³ 

[1] Centre for Cardiovascular Sciences, University of Edinburgh, Edinburgh EH16 4TJ, UK;Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK;Edinburgh Imaging, University of Edinburgh, Edinburgh EH16 4TJ, UK;

关键词: cerebral small vessel disease;    MRI;    ferumoxytol;    USPIO;    inflammation;    relaxometry;   

DOI  :  10.3390/ijms20030776

来源: DOAJ

【 摘 要 】

A protocol for evaluating ultrasmall superparamagnetic particles of iron oxide (USPIO) uptake and elimination in cerebral small vessel disease patients was developed and piloted. B₁-insensitive R₁ measurement was evaluated in vitro. Twelve participants with history of minor stroke were scanned at 3-T MRI including structural imaging, and R₁ and R₂* mapping. Participants were scanned (i) before and (ii) after USPIO (ferumoxytol) infusion, and again at (iii) 24–30 h and (iv) one month. Absolute and blood-normalised changes in R₁ and R₂* were measured in white matter (WM), deep grey matter (GM), white matter hyperintensity (WMH) and stroke lesion regions. R₁ measurements were accurate across a wide range of values. R₁ (p < 0.05) and R₂* (p < 0.01) mapping detected increases in relaxation rate in all tissues immediately post-USPIO and at 24–30 h. R₂* returned to baseline at one month. Blood-normalised R₁ and R₂* changes post-infusion and at 24–30 h were similar, and were greater in GM versus WM (p < 0.001). Narrower distributions were seen with R₂* than for R₁ mapping. R₁ and R₂* changes were correlated at 24–30 h (p < 0.01). MRI relaxometry permits quantitative evaluation of USPIO uptake; R₂* appears to be more sensitive to USPIO than R₁. Our data are explained by intravascular uptake alone, yielding estimates of cerebral blood volume, and did not support parenchymal uptake. Ferumoxytol appears to be eliminated at 1 month. The approach should be valuable in future studies to quantify both blood-pool USPIO and parenchymal uptake associated with inflammatory cells or blood-brain barrier leak.

【 授权许可】

Unknown