Fluid-fluid level containing bone lesions are best seen on MRI, although with narrow window width they can also be appreciated on CT.
Their prevalence is estimated at ~3% of bone and soft tissue tumors 1.
Their presence is non-specific, as they are seen in both benign and malignant lesions:
- aneurysmal bone cyst (ABC)
- simple bone cyst: especially after fracture
- telangiectatic osteosarcoma
- uncommon causes
There is a mnemonic for fluid-fluid levels on MRI.
- 1. Van dyck P, Vanhoenacker FM, Vogel J et-al. Prevalence, extension and characteristics of fluid-fluid levels in bone and soft tissue tumors. Eur Radiol. 2006;16 (12): 2644-51. doi:10.1007/s00330-006-0250-1 - Pubmed citation
- 2. Davies AM, Sundaram M, James SJ. Imaging of Bone Tumors and Tumor-Like Lesions, Techniques and Applications. Springer. (2009) ISBN:3540779825. Read it at Google Books - Find it at Amazon
- 3. Catalano P, Fang-Hui E, Som PM. Fluid-fluid levels in benign neurogenic tumors. AJNR Am J Neuroradiol. 1997;18 (2): 385-7. AJNR Am J Neuroradiol (abstract) - Pubmed citation