FIGURE 7. Small lymph node adjacent to thyroid gland. (A) As result of contrast enhancement of thyroid after application of iodine-based intravenous contrast agent, hypodense lymph node (arrow) was clearly distinguished from thyroid parenchyma. Increased ¹⁸F-FDG uptake on PET (B) was accurately attributed to this lymph node rather than to thyroid gland (C). Without contrast enhancement, similar densities of parenchymal organs and lymph nodes frequently render differentiation of organ metastasis from adjacent lymph node metastasis difficult.