ASYMPTOMATIC FUNCTIONAL POPLITEAL ARTERY ENTRAPMENT - DEMONSTRATION AT MR-IMAGING

PURPOSE: To determine if functional popliteal entrapment can occur in healthy subjects and to define the mechanism of vascular compression. MATERIALS AND METHODS: The right lower extremities were examined in 13 subjects (nine men 27-34 years of age, mean age 31 years; four women 29-44 years of age, mean age 34 years) with no symptoms of popliteal a rtery entrapment. Magnetic resonance (MR) and Doppler ultrasound image s were obtained while the subjects were at rest and while they perform ed plantar flexion against resistance. RESULTS: Blood flow during plan tar flexion ceased in nine of 13 subjects (69%) and was impaired in th ree of 13 (23%). MR images showed muscular compression of the poplitea l artery at two levels: between the plantaris muscle and the medial he ad of the gastrocnemius muscle and between the plantaris and popliteus muscles. CONCLUSION: Functional impairment of popliteal arterial flow during plantar flexion occurs in subjects who have no symptoms of pop liteal entrapment syndrome.