Fig. 3
From: Ultrasonography of thyroid nodules: a pictorial review
(a) A markedly hyper-echogenic nodule is considered indeterminate regarding its risk of malignancy. (b) A nodule containing an echogenic focus that appears to be cystic is indeterminate. (c) Doppler assessment of a nodule showing mixed vascularity, which consists of both peripheral and intra-nodular vasculature