Whole-Body MR Imaging

Abstract

Whole-body magnetic resonance imaging (whole-body MR imaging) has evolved rapidly over the past decade as technical developments have enabled large field of view (FOV) imaging in clinically feasible timeframes, while preserving high contrast and spatial resolution. As a consequence, whole-body MR imaging has become a valuable tool in assessing a range of diffuse, multifocal, and/or multisystem disease processes. This is particularly appealing in the pediatric population given its lack of ionizing radiation, and whole-body MR imaging has emerged as an alternative imaging modality to other large FOV imaging techniques such as computed tomography (CT), positron emission tomography (PET), and radiographic skeletal surveys. In this chapter, whole-body MR imaging techniques are described, detailing standard pulse sequences, imaging planes and anatomic coverage suited to a range of indications, as well as protocols adapted to different pediatric disease entities. The spectrum of pathology discussed includes congenital disorders, specifically cancer predisposition syndromes such as Li-Fraumeni syndrome; other neoplastic disorders encompassing lymphoma, Langerhans cell histiocytosis, and treatment-related complications (e.g., osteonecrosis); infectious and noninfectious inflammatory conditions including fever of unknown origin (FUO); trauma; and postmortem imaging. Whole-body MR imaging can facilitate diagnosis, documents disease burden and treatment response, and guides invasive procedures such as biopsy. Whole-body MR imaging interpretation is also discussed, highlighting tools to optimize disease detection while minimizing pitfalls that can result in false positive or false negative findings.