Contrast enhanced magnetic resonance imaging of the liver.

Dynamic contrast enhanced magnetic resonance imaging (DCE MRI) is a useful tool to characterise and stage a disease. Here we investigate the application of DCE MRI to the liver, an organ subject to large excursions during normal breathing. For DCE MRI it is important to have an estimate of the longitudinal relaxation time parameter T1. We show that by using a T1 mapping approach, which takes into account inaccuracies in transmitted flip angles, we obtain a smoother T1 map, resulting in a more consistent parameter estimation for the subsequent analysis. The dynamic imaging protocol described enables the acquisition of high resolution unblurred images by simulating the normal breathing cycle. The contrast enhanced data is aligned, first rigidly, then non-rigidly, and input to a two-compartment pharmacokinetic model. We observe that rigid registration markedly improves the parameter estimation, but is insufficient in clinically important heterogeneous areas.