A novel 3-D power Doppler ultrasound approach to the quantification of achilles tendon neovascularity.

To investigate the amount of neovascularization in the symptomatic Achilles tendon, we developed a novel three-dimensional (3-D) power Doppler ultrasound scanning system to prospectively examine 10 patients with 12 symptomatic Achilles tendons, as well as 20 asymptomatic Achilles tendons as a control group. The mean volume of neovascularity (VON) in the whole Achilles tendon was calculated during the phase of the cardiac cycle displaying maximum vascularity and also during the phase of the cardiac cycle displaying the minimum. The mean VONs in the control group were found to be 0.41 mm(3) (maximum) and 0.02 mm(3) (minimum), respectively. The mean VONs in patients with painful Achilles tendon were 380 mm(3) (maximum) and 70.3 mm(3) (minimum), respectively. The initial results showed that the 3-D power Doppler ultrasound system could be used to measure the mean VON in controls and in patients with symptomatic Achilles tendinopathy. The results demonstrated a significantly greater VON in the maximum phase compared with the minimum phase as well as in the patient group compared with that in the control group. The system was therefore capable of defining the degree of vascularity in the Achilles tendon.