MRI is a technique based on magnetic fields and does not require the use of ionizing radiation. Although there are no known side effects associated with MRI, a few precautions should be taken because of the 3T magnetic field. This implicates that all metal and magnetized objects must be removed from the patients before entering the MRI room. Patients with a pacemaker, a cardiac defibrillator or other implanted conductors/prostheses are for reason not eligible for the study.

During the MRI examination, an intravenous contrast agent will be administered. In most cases, patients do not experience any discomfort and the use of this contrast agent is part of the clinical routine.

Patients will be scanned before (baseline) and after (the day of embolization, 3 days and 3 months after embolization). Measurements of signal intensity (SI) will be performed placing ROIs in the central portion of the lesion avoiding areas of artifact. Apparent diffusion coefficients (ADCs) will be calculated at different time points (before and after embolization). Signal intensity measurements on the dynamic contrast enhanced imaging data sets will be performed.