Magnetization transfer MRI in pancreatic cancer xenograft models.

Magnetization transfer magnetic resonance imaging measurements were performed in three pancreatic ductal adenocarcinoma mouse xenograft models. For each of 28 pancreatic ductal adenocarcinoma xenografts, MT ratios (MTRs) were calculated and compared to histologic fibrosis levels from reference standard trichrome staining. MTR was found to be significantly higher in tumors grown using BxPC-3 cell line (39.4±5.1, mean±SD) compared to the MTR for the tumors grown from Panc-1 (32.4±2.8) and Capan-1 (27.3±2.9) cell lines (P<0.05 for each comparison). Histologic measurements showed a similar trend with BxPC-3 tumors demonstrating significantly higher fibrosis levels (percentage of fibrotic tissue area, 6.48±2.59) when compared to Panc-1 (3.54±2.18) and Capan-1 (2.07±1.60) tumors. MTR measurements were well correlated to quantitative fibrosis levels (r=0.69, P=0.01). Results indicated that MTR measurements offer the potential to serve as a valuable in vivo biomarker of desmoplasia in pancreatic ductal adenocarcinoma.