MRI characteristics of cysts and “cyst-like” lesions in and around the knee: what the radiologist needs to know

Authors: Evangelos Perdikakis1 and Vasilios Skiadas1

(1)Department of Radiology, 412 General Military Hospital-212 Mobile Army Surgical Hospital, Terma Lefkou Pyrgou, Xanthi, 67100, Greece.





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.




Discussion


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.