The findings on your MRI are common for
Achilles tendinosis. Tendinosis is represented as the abnormal thickening of the tendon, which is consistent with tendon deterioration. Tendonitis, is inflammation. This means that the collagen fibers which make up the tendon become disorganized and infiltrated with small blood vessels. The result is a weak tendon. The infracalcaneal spur is not associated with the Achilles tendon. The peroneal brevis is the tendon on the outside of the leg which helps to stabilize the foot. The high signal intrasubstance tear could be a peroneal tendon tear or tendonitis. Usually pain at the peroneal tendons is due to an overuse injury or acute tear, but also can be a secondary problem as a result of ankle instability. It is hard to give you specific answers without a history or an evaluation - but hopefully this information helps.