Title:Fluid-fluid Levels in Musculoskeletal Tumor Imaging
VOLUME: 17 ISSUE: 2
Author(s):Shinji Tsukamoto, Costantino Errani*, Fabio Facchini, Panayiotis Papagelopoulos and Andreas F. Mavrogenis
Affiliation:Department of Orthopaedic Surgery, Nara Medical University, Nara, Department Orthopaedic Oncology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Intensive Care and Pain Therapy, IRCCS Istituto Ortopedico Rizzoli, Bologna, First Department of Orthopaedics, National and Kapodistrian University of Athens, School of Medicine, Athens, First Department of Orthopaedics, National and Kapodistrian University of Athens, School of Medicine, Athens
Keywords:Fluid-fluid levels, imaging, differential diagnosis, bone tumors, soft tissue tumors, prognosis.
Abstract:Fluid-fluid levels result from the separation of two fluids of differing densities within a
cavernous space with the boundary between the two layers running in a horizontal plane at 90 degrees
to the direction of gravity. Magnetic resonance imaging is the most sensitive imaging modality
to identify fluid-fluid levels. Although the most common bone lesions containing fluid-fluid levels
are aneurysmal bone cyst and telangiectatic osteosarcoma, fluid-fluid levels can be observed in
a wide variety of bone and soft tissue lesions. Therefore, fluid-fluid levels cannot be considered diagnostic
of any particular type of tumor and the diagnosis should be made on the basis of other clinical,
radiological and pathological findings. This article summarizes the pathophysiology and imaging
characteristics of fluid-fluid levels and discusses the differential diagnosis of tumors with this
imaging sign.
