The central scar and the fibrous septa are often difficult to visualize on US.However, when apparent, the central scar is usually hyperechoic while the fibrous septa are hypoechoic. Characteristic findings at color Doppler US include the presence of a central feeding artery with a stellate or spokewheel pattern, which corresponds to vessels running into the radiating fibrous septa from the central scar (Fig. ultrasounf images bellow). The spectral analysis may show an intratumoral pulsatile waveform with high diastolic flow and low resistive index corresponding to malformed arteries, and a continuous waveform which could represent a draining vein of the neoplasm US in general is a non-specific imaging method for the characterization of non-classic FNH.
“Ultrasound pictures of FNH”