Fig. 2. Magnetic resonance imaging of the knee. (A, B) Swelling with enhancement of the right common peroneal nerve (A, white arrow), which winds around the lateral aspect of the fibular head (asterisk), compared with the left common peroneal nerve (B, white arrow) on an maximum intensity projection image from a coronal-reconstructed three-dimensional short tau inversion recovery sampling perfection with application optimized contrasts with variable flip-angle evolutions image. (C) Ill-defined hyper signal intensity changes in right peroneal-innervated muscles (tibialis anterior, extensor digitorum longus, and peroneal longus) (white arrow heads) compared with no signal change in tibial-innervated muscles on the proton density axial turbo spin echo fat-suppression magnetic resonance image.