MR-imaging characteristics and post-therapeutic morphologic changes in liver metastases from neuroendocrine tumors

Introduction: Liver metastases of neuroendocrine tumors (NET) show MRI-characteristics, which differ from most other liver metastases; i.e. they are hypervascular in the hepatic arterial dominant phase (1;2). The response of the metastases to treatment is not sufficiently reflected by the RECIST criteria. However, metastases of NET rather show characteristic changes to treatment, like central necrosis, hemorrhagic transformation and fluid-fluid levels, which are otherwise rare in hepatic metastases. The aim of the current study was to analyze, describe and quantify MR-morphologic characteristics and changes in liver metastases of NET at baseline and at different timepoints in treatment follow up. Additionally it shall be analyzed, how these MR-morphologic characteristics are reflected by tracer uptake in PET-CT and by changes in tumor perfusion.