Figure 7b. (a) Normal anatomy of the lateral and medial plantar nerves. Coronal oblique T1-weighted MR image (500/12) obtained at the level of the metatarsal bases shows the medial plantar nerve branches (circled), oblique head of the adductor hallucis muscle (thick arrow), flexor longus hallucis and flexor digitorum longus tendons (arrowheads), flexor digitorum brevis muscle (FDB), lateral plantar nerve branches (thin arrow), abductor digiti quinti muscle (ADQM), and abductor hallucis muscle (AH). 1rst M = first metatarsal. (b, c) Distal entrapment of the medial and lateral plantar nerve branches in a 60-year-old patient with plantar midtarsal pain radiating to the medial plantar aspect of the toes. Contiguous coronal T2-weighted MR images (3,500/119) show an arthrosynovial cyst (* in b) that is responsible for compression of the medial plantar nerve branches (circled in c).