Magnetic Resonance Imaging is already the gold-standard for detection and differential diagnosis of cerebral diseases in pediatric patients. However, due to the increasing availability of Magnetic Resonance Imaging and the ongoing discussion on radiation exposure especially of pediatric patients in CT imaging, MR imaging studies in pediatric patients become more and more common in the body area, as well. This book gives an overview on differential diagnosis of tumors, pseudotumors and congenital malformations which may simulate a mass in pediatric patients. Differential diagnosis is based on the location of the mass and multiple imaging examples allow the reader to become familiar with the typical and atypical presentation of different diseases. The technical requirements to achieve a sufficient image quality and technical issues of pediatric imaging in general are discussed and additional information on clinical issues and follow-up studies are presented. This book will prove helpful for radiologists wishing to further expand or consolidate their knowledge on pediatric body imaging and will help them to answer the important clinical questions raised in imaging of pediatric tumors.