[Influencing Factors and Prediction Model of Performance of Needle Visualization in Fine Needle Aspiration of Thyroid Nodules].

Objective To investigate the influencing factors and establish a model predicting the performance of needle visualization in fine-needle aspiration (FNA) of thyroid nodules. Methods This study prospectively included 175 patients who underwent FNA of thyroid nodules in the Department of Ultrasound in China-Japan Friendship Hospital and compared the display of the needle tips in the examination of 199 thyroid nodules before and after the application of needle visualization.We recorded the location,the positional relationship with thyroid capsule,ultrasonic characteristics,and the distribution of the soft tissue strip structure at the puncture site of the nodules with unclear needle tips display before using needle visualization.Furthermore,according to the thyroid imaging reporting and data system proposed by the American College of Radiology,we graded the risk of the nodules.Lasso-Logistic regression was employed to screen out the factors influencing the performance of needle visualization and establish a nomogram for prediction. Results The needle tips were not clearly displayed in the examination of 135 (67.8%) and 53 (26.6%) nodules before and after the application of needle visualization,respectively,which showed a significant difference (<0.001).Based on the positional relationship between the nodule and capsule,anteroposterior/transverse diameter (A/T) ratio,blood supply,and the distribution of subcutaneous strip structure at the puncture site,a nomogram was established to predict the probability of unclear display of the needle tips after application of needle visualization.The C-index of the prediction model was 0.75 (95%=0.67-0.84) and the area under the receiver operating characteristic curve was 0.72.The calibration curve confirmed the appreciable reliability of the prediction model,with the C-index of 0.70 in internal validation. Conclusions Needle visualization can improve the display of the needle tip in ultrasound-guided FNA of thyroid nodules.The nomogram established based on ultrasound features such as the positional relationship between the nodule and capsule,A/T ratio,blood supply,and the distribution of subcutaneous strip structure at the puncture site can predict whether needle visualization is suitable for the examination of nodules.