Figure 4a. Transverse US images of mostly cystic thyroid nodule with a mural component containing flow. (a) Gray-scale image shows predominantly cystic nodule (calipers) with small solid-appearing mural component (arrowheads). (b) Addition of color Doppler mode demonstrates flow within mural component (arrowheads), confirming that it is tissue and not debris. US-guided FNA can be directed into this area. The lesion was benign at cytologic examination.