Quantitative T 2 imaging of metastatic human breast cancer to brain in the nude rat at 3 T

• Published in: NMR in biomedicine 2011-04, Vol.24 (3), p.325-334
• Main Authors: Song, Ho‐Taek, Jordan, Elaine K., Lewis, Bobbi K., Gold, Eric, Liu, Wei, Frank, Joseph A.
• Format: Article
• Language: English
• ISSN: 0952-3480; 1099-1492
• DOI: 10.1002/nbm.1596

This study uses quantitative T 2 * imaging to track ferumoxides–protamine sulfate (FEPro)‐labeled MDA‐MB‐231BR‐Luc (231BRL) human breast cancer cells that metastasize to the nude rat brain. Four cohorts of nude rats were injected intracardially with FEPro‐labeled, unlabeled or tumor necrosis factor‐related apoptosis‐inducing ligand(TRAIL)‐treated (to induce apoptosis) 231BRL cells, or saline, in order to develop metastatic breast cancer in the brain. The heads of the rats were imaged serially over 3–4 weeks using gradient multi‐echo and turbo spin‐echo pulse sequences at 3 T with a solenoid receive‐only 4‐cm‐diameter coil. Quantitative T 2 * maps of the whole brain were obtained by the application of single‐exponential fitting to the signal intensity of T 2 * images, and the distribution of T 2 * values in brain voxels was calculated. MRI findings were correlated with Prussian blue staining and immunohistochemical staining for iron in breast cancer and macrophages. Quantitative analysis of T 2 * from brain voxels demonstrated a significant shift to lower values following the intracardiac injection of FEPro‐labeled 231BRL cells, relative to animals receiving unlabeled cells, apoptotic cells or saline. Quartile analysis based on the T 2 * distribution obtained from brain voxels demonstrated significant differences ( p