2D and 3D radial multi-gradient-echo DCE MRI in murine tumor models with dynamic R*2-corrected R1 mapping
✍ Scribed by Julien Vautier; Melanie Heilmann; Christine Walczak; Joël Mispelter; Andreas Volk
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 396 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0740-3194
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✦ Synopsis
Abstract
Dynamic contrast‐enhanced MRI is extensively studied to define and evaluate biomarkers for early assessment of vasculature‐targeting therapies. In this study, two‐dimensional and three‐dimensional radial multi‐gradient‐echo techniques for dynamic R*~2~‐corrected R~1~ mapping based on the spoiled gradient recalled signal equation were implemented and validated at 4.7 T. The techniques were evaluated on phantoms and on a respiratory motion animated tumor model. R~1~ measurements were validated with respect to a standard inversion‐recovery spin‐echo sequence in a four‐compartment phantom covering a range of relaxation rates typically found in tumor tissue. In the range of [0.4, 3] sec^−1^, R~1~ differences were less than 10% for both two‐dimensional and three‐dimensional experiments. A dynamic contrast‐enhanced MRI pilot study was performed on a colorectal tumor model subcutaneously implanted in mice at the abdominal level. Low motion sensitivity of radial acquisition allowed image recording without respiratory triggering. Three‐dimensional K^trans^ maps and significantly different mean K^trans^ values were obtained for two contrast agents with different molecular weights. The radial multi‐gradient‐echo approach should be most useful for preclinical experimental conditions where the tissue of interest experiences physiologic motion, like spontaneous extracerebral tumors developed by transgenic mice, and where dynamic contrast‐enhanced MRI is performed with high‐relaxivity contrast agents. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.