The combination of ultrasound and CT evaluate lymph node metastasis of thyroid papillary carcinoma in different compartments

Objective:To evaluate the role of the combination of ultrasound and enhanced CT in analyzing lymph node metastasis in thyroid papillary carcinoma(PTC)patients by compartment.Method:Clinical data of 115 cases(141sides)with PTC were collected.All had undergone ultrasound in neck and enhanced CT both in neck and in imediastinum before surgery.They were divided into ultrasound group,CT group,and the combination of ultrasound and enhanced CT group to evaluate lymph node metastasis.Result:For the central compartment,the accuracy of ultrasound was 61.0%,CT was 48.9%,and the combination of ultrasound and CT was 62.4%.For the lateral compartment,ultrasound was 87.9%,CT was 78.7%,the combination of ultrasound and CT was 85.8%.Ultrasound had higher accuracy than CT in the central(P0.05)and lateral(P0.05)compartment.The combination of ultrasound and CT had higher accuracy than CT in the central compartment(P0.05),but there was no significant difference in the lateral compartment(P0.05).There was no significant difference in accuracy between ultrasound and the combination of ultrasound and CT neither in central(P0.05)nor in lateral(P 0.05)compartment.Six cases of lymph node metastasis in mediastinum and 1case in parapharyngeal space detected by CT were pathologically proven.CT found that five patients with pulmonary metastasis.Conclusion:The combination of ultrasound and CT or single ultrasound has higher accuracy in preoperative evaluation than single CT for lymph node metastasis in PTC.CT can assess some compartments such as mediastinum which can't be detected by ultrasound,and at the same time to evaluate lung metastasis.To evaluate lymph node metastasis in PTC,the combination of ultrasound and CT is more accurate and considerate than single method.