Fig. 1From: Value of CEUS features in diagnosing thyroid nodules with halo sign on B-mode ultrasoundA papillary thyroid carcinoma in a 40-year-old woman. A Greyscale ultrasound showed that there was a halo surrounding the thyroid nodule. B Contrast-enhanced ultrasound revealed hypo-enhancement at peak, with a irregular low-enhancing ring (at the 20th second after the injection of contrast agent)Back to article page