title: MRI characteristics of cysts and "cyst-like" lesions in and around the knee: what the radiologist needs to know.
abstract: OBJECTIVE
  A variety of benign cystic or "cyst-like" lesions may be encountered during a routine magnetic resonance imaging (MRI) of the knee. These lesions comprise a diverse group of entities from benign cysts to complications of underlying diseases. In addition, normal anatomic bursae and recesses may be misdiagnosed as an intra-articular cystic lesion when they are distended. However, the majority of the aforementioned lesions have characteristic MR appearances that allow a confident diagnosis, thus obviating the need for additional imaging or interventional procedures.
  
  
  RESULTS
  This article includes a comprehensive pictorial essay of the characteristic MRI features of common and uncommon benign cysts and "cyst-like" lesions in and around the knee joint.
  
  
  CONCLUSIONS
  For accurate assessment of the "cystic structure", a radiologist should be able to identify typical MRI patterns that contribute in establishing the correct diagnosis and thus guiding specific therapy and avoiding unwarranted interventional procedures such as biopsy or arthroscopy.
  
  
  CONCLUSIONS
  • Cystic lesions are common in knee MRI and the commonest, the Baker's cyst, has an incidence of 38 %. • Synovial cysts, meniscal cysts, normal knee bursae and recesses have characteristic MR appearances. • Miscellaneous "cyst-like" lesions may require a more dedicated MR protocol for a correct diagnosis.
authors.affiliation: Department of Radiology, 412 General Military Hospital-212 Mobile Army Surgical Hospital, Terma Lefkou Pyrgou, Xanthi, 67100, Greece, perdikakis_ev@yahoo.gr.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Perdikakis
authors.forename: Vasilios
authors.initials: V
authors.lastname: Skiadas