Dynamic Contrast-enhanced Mri in Rectal Tumours – Initial Reproducibility Measurements at 3 T with and without Bowel Relaxant

Introduction. Dynamic contrast-enhanced (DCE) MRI and the fitting of pharmacokinetic (PK) models to the resulting image data has been widely used in oncology to investigate tumour vascularity, particularly in conjunction with treatment response. Despite the improved SNR offered by 3T MRI systems, to date the majority of these studies have been performed at 1.5T. This may be due in part to concerns over reproducibility of DCE-MRI at 3T, where increased RF inhomogeneities are likely to impact on the quantification of T1 values required for accurate PK modelling. Although there have been a number of studies looking at reproducibility of DCE-MRI in tumours at 1.5 T [1,2], there has been relatively little corresponding work at higher field strengths and to our knowledge no reports in rectal cancer alone.