Value of Dual-Energy Computed Tomography for Diagnosing Cervical Lymph Node Metastasis in Patients With Papillary Thyroid Cancer

Objective The objective of this study was to determine the value of dual-energy computed tomography (DECT) for the diagnosis of cervical lymph node metastasis in papillary thyroid cancer. Methods The normalized iodine concentration (NIC) and the slope of the spectral Hounsfield unit curve (lambda(HU)) in the arterial and venous phases were measured using iodine-overlay images and spectral curves. Quantitative DECT data and qualitative conventional CT data were analyzed by radiologists. Results The best qualitative parameter for lymph node metastasis detection was obvious node enhancement, and the best quantitative parameter for detection was arterial-phase NIC, which showed high sensitivity, specificity, and accuracy values at an optimal threshold of 25.8%. The best combination of qualitative and quantitative parameters consisted of obvious enhancement and arterial-phase NIC; this combination showed a sensitivity of 90.8% and a specificity of 80.5%. Conclusions The DECT quantitative parameters NIC and lambda(HU) can be an additional tool to diagnose cervical lymph node metastasis.