MRI and DSA findings in popliteal artery entrapment syndrome.

PURPOSE To evaluate magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) findings in popliteal artery entrapment syndrome. MATERIALS AND METHODS Seven limbs of 6 patients (5 men and 1 woman; mean age, 36 +/- 12 years) with popliteal artery entrapment syndrome were evaluated retrospectively. Both MRI and DSA were performed on each affected limb. RESULTS MRI findings established the diagnosis of type-3 popliteal artery entrapment syndrome in 4 limbs, and type-2 in 3 limbs. Abnormal MRI findings included popliteal artery thrombosis with aneurysm in 2 limbs (29%), popliteal artery thrombosis without aneurysm in 1 limb (14%), aberrant fibrous band in 3 limbs (43%), aberrant thick muscle bundle in 1 limb (14%), insertion anomaly of medial head of the gastrocnemius muscle (MHG) in 3 limbs (43%), lateral deviation of the MHG in 4 limbs (57%), hypertrophy of the MHG in 1 limb (14%), and atrophy of the MHG in 2 limbs (29%). Deviation of the popliteal artery in 4 limbs (57%) and distal crural embolic occlusions in 2 limbs (29%) were detected with both angiography and MRI imaging. DSA was diagnostic in 2 limbs of 1 patient, and MRI was diagnostic in all limbs examined. CONCLUSION Popliteal artery entrapment syndrome should be considered in patients younger than 50 years of age with isolated popliteal artery stenosis or occlusion. MRI is the preferred imaging modality for diagnosis of entrapment syndrome, and may obviate the use of DSA.