Imaging features of bakers cyst MR T1 low signal T2 high signal Grey scale - well-defined cyst with a 'neck' at its deepest extent - extending into the joint space between the semimembranosus tendon and the medial head of the gastrocnemius - identification of a fluid-filled structure at the posteromedial knee is suggestive of a popliteal cyst, but identification of the 'neck' between the tendons is necessary for a definitive diagnosis - anechoic, but may contain internal debris