American Journal of Interventional Radiology

1-6

Authors: Shyamkumar N Keshava

Purpose: The purpose of this study was to study the effects of ankle position on Doppler measurements of popliteal artery (PA) and posterior tibial arteries (PTA) in healthy individuals. Materials and Methods: PA and PTAs of 20 healthy (questionnaire based and ankle brachial pressure index assessed) subjects (40 limbs) were studied with Doppler ultrasound in neutral and after active ankle joint movements. Results: The mean increase in the velocity of PA from neutral position was more with plantar flexion as compared to dorsiflexion (22 vs. 15 cm/s, respectively). PA showed a significant change in waveform, with the absence of diastolic flow, more with dorsiflexion than plantar flexion (46% and 33%, respectively). Similarly, mean increase in the velocity of PTA was more with plantar flexion as compared to dorsiflexion (mean 36.7 vs. 33.2 cm/s, respectively). PTA showed a significant change from triphasic to biphasic and monophasic on plantar flexion (up to 39.2%). Dorsiflexion also showed similar results, however, to a lesser degree. None of the PA or PTA showed complete absence of flow on these maneuvers. Conclusion: Predominantly, a pattern of increase is seen in the mean velocity on plantar flexion and dorsiflexion in both the arteries. The most common change in the Doppler waveforms was the absence of diastolic flow (biphasic pattern). Our study confirms that waveforms in the popliteal and PTA can even be monophasic depending on the position of the foot in normal healthy individuals, therefore, when biphasic/monophasic in appearance, they should not be interpreted as abnormal or diseased.