Quantitative perfusion measurements of liver metastasis from DCE-MRI using Inversion Recovery TrueFISP

Introduction Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been widely used to evaluate anti-angiogenic and anti-vascular agents in clinical trials [1]. Data acquisition in DCE-MRI is mostly based on the application of FLASH protocols either as multi-slice 2D or 3D with long repetition times. However, tumors of the liver (or lung) on the one hand show fast Gd uptake kinetics with a time to peak enhancement phase in some cases in the order of ~10-15s, while on the other hand are affected by spatial variation due to patient breathing motion. We developed a DCE-MRI protocol using an Inversion Recovery trueFisp (IR trueFISP) sequence for DCE-MRI of liver metastasis. The approach is based on the application of an inversion pulse followed by the acquisition of a single 2D slice with a fast repeated data acquisition period to freeze breathing motion. The increased image contrast with a high contrast-to-noise ratio (CNR) between tumor and surrounding healthy tissue allows an accurate tracking of the tumor during breathing. Moreover, T1 quantitation allows direct determination of contrast agent concentration values.