Whole-body magnetic resonance imaging: techniques and non-oncologic indications.

Whole-body MRI is increasingly utilized for assessing oncologic and non-oncologic diseases in infants, children and adolescents. Focusing on the non-oncologic indications, this review covers technical elements required to perform whole-body MRI, the advantages and limitations of the technique, and protocol modifications tailored to specific indications. Rheumatologic diseases account for the majority of non-oncologic whole-body MRI performed in pediatric patients at the author's institution. Whole-body MRI helps in establishing the diagnosis, documenting disease extent and severity, and monitoring treatment response in enthesitis-related arthritis (ERA) and chronic recurrent multifocal osteomyelitis (CRMO). Other non-oncologic indications for whole-body MRI include osteomyelitis (usually pyogenic), pyrexia of unknown origin, neuromuscular disorders, inherited and inflammatory myopathies such as juvenile dermatomyositis and polymyositis, avascular necrosis, and fat/storage disorders. Use of whole-body MRI in postmortem imaging is rising, while whole-body MRI in non-accidental injury is considered to be of limited value. Imaging findings for a range of these indications are reviewed with whole-body MRI examples.