Ultrasound versus MRI in the diagnosis of orthopaedic sports injuries, emphasis on tendons

US is superior to MRI in depicting the ultrastructure of superficially located tendons and in demonstrating pathological vascularisation in and around tendons by using power Doppler US. In this regard US findings are helpful in defining "tendinosis" in its different stages. Moreover dynamic US is able to demonstrate intermittent tendon dislocation and is an advantage to differentiate subtotal and total thickness tendon tears. Only deeply located tendons in corpulent patients, i.e. hamstrings origin and gluteus tendon insertions, are better documented on MRI. Paratenonitis in type I tendons is better documented on MRI. MRI and US have a comparable sentitivity to demonstrate paratenonitis in type II tendons i.e. tenovaginitis and fluid at tendon sheats. Thus ultrasound is preferred over MRI not only because of economy and availability but also because of its diagnostic advantage to demonstrate and stage superficial tendon and juxtatendinous disorders.