The usual imaging requested for a patient with knee pain is MRI to examine ligaments and menisci as well as articular cartilage and other extra-articular structure. Popliteal fossa lesions rarely cause alarming knee pain

The most common cystic lesion seen in the popliteal fossa is a Baker's cyst with aneurysms (both true and false) being uncommon. Endovascular coiling is the treatment of choice.