Objectives and Methods 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. Teaching points • 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.

Background: Non-alcoholic fatty liver disease (NAFLD) and its severe form, non-alcoholic steatohepatitis (NASH), are major health problems worldwide. Genetics may play a role in the pathogenesis of NAFLD/NASH. Aim: To investigate the prevalence of NAFLD/NASH in 5,400 military personnel and evaluate the effect of treatment with 3 statins on NAFLD/NASH using 2 non-invasive scores [NAFLD Activity Score (NAS); Fibrosis-4 score (FIB-4)]. Methods: During the mandatory annual medical check-up, military personnel underwent a clinical and laboratory evaluation. Participants with NAFLD/NASH were randomized into 4 groups (n=151 each): diet-exercise, atorvastatin, rosuvastatin, or pitavastatin for 1 year (i.e., until the next routine evaluation). Results: From all the participants, 613 had NAFLD/NASH (prevalence 11.3 vs 39.8% in the general population, p<0.001), and a total of 604 consented to participate in the study. After a year of treatment, the diet-exercise group showed no significant changes in both scores (NAS 4.98 baseline vs. 5.62, p=0.07; FIB-4 3.42 vs. 3.52, p=0.7). For the atorvastatin group, both scores were reduced (NAS 4.97 vs 1.95, p<0.001, FIB-4 3.56 vs 0.83, p<0.001), for rosuvastatin (NAS 5.55 vs 1.81, p<0.001, FIB-4 3.61 vs 0.79, p<0.001), and for pitavastatin (NAS 4.89 vs 1.99, p<0.001, FIB-4 3.78 vs 0.87, p<0.001). Conclusions : Atorvastatin, rosuvastatin, and pitavastatin have a beneficial and safe effect in NAFLD/NASH patients as recorded by the improvement in the NAS (representing NAFLD activity) and FIB-4 (representing liver fibrosis) scores. Since both those with and without NAFLD/- NASH shared several baseline characteristics, genetics may play a role in the pathogenesis of NAFLD/NASH and its treatment with statins.