Typical dual-energy CT images and iodine maps of metastatic lymph node with a diameter of 0.47 cm in a 51-year-old woman with PTC. (A) Contrast-enhanced monochromatic image in the arterial phase of a metastatic lymph node (area, 12 mm2, CT value, 88.9±12.1 HU). (B) Iodine map in the arterial phase of a metastatic lymph node (area, 12 mm2; iodine concentration, 5.7 mg/mL). (C) Contrast-enhanced monochromatic image in the venous phase of a metastatic lymph node (area, 12 mm2, CT value, 78.6±15.1 HU). (D) Iodine map in the venous phase of a metastatic lymph node (area, 12 mm2; iodine concentration, 3.5 mg/mL). CT, computed tomography; PTC, papillary thyroid carcinoma.