Independent risk factors and feasibility of ultrasound diagnosis of ultrasound-guided non-cytologically diagnostic thyroid nodules.

BACKGROUND

To explore the independent risk factors and feasibility of ultrasound diagnosis of ultrasound-guided non-cytologically diagnostic thyroid nodules.

METHODS

This study included 200 patients with thyroid nodules that were diagnosed or suspected of being Thyroid Imaging Reporting and Data System (TI-RADS) 4 nodules between January 2017 and January 2019. All patients received surgical treatment and pathological diagnosis, and were divided into a cytologically diagnostic group and a non-cytologically diagnostic group based on whether they could be diagnosed by ultrasound-guided fine needle aspiration cytology (UG-FNAC). Patients were further divided into benign and malignant groups according to the results of surgical pathology. Logistic regression analysis was used to clarify the risk factors that could not be cytologically diagnosed in TI-RADS 4 nodules. For the diagnosis of benign and malignant nodules, we combined contrast-enhanced ultrasound (CEUS) and ultrasound elastography (UE) to establish a joint scoring strategy. The diagnostic value of the joint scoring strategy was evaluated by receiver operating characteristic (ROC) curve.

RESULTS

A total of 216 TI-RADS type 4 nodules were detected in 200 patients. Among them, 40 nodules were included in the non-cytologically diagnostic group, and 176 nodules were included in the cytologically diagnostic group. The multi-parameter logistic regression showed that: aspect ratio <1, irregular edge, scattered coarse calcification, middle layer, and lower layer were independent influencing factors leading to undiagnosed puncture cytology. Among the 216 nodules in 200 patients, 168 were pathologically diagnosed as malignant nodules (malignant group), and 48 nodules were diagnosed as benign nodules (benign group). According to the joint scoring strategy, the distribution of comprehensive scores changes significantly at 5-6 scores while in malignant nodules, the distribution of comprehensive scores changes significantly at 6-7 scores. ROC curve analysis showed that the diagnostic value was the highest when '6 scores' was used as the critical point for diagnosis [area under curve (AUC) =0.893, P<0.05].

CONCLUSIONS

The combined scoring strategy of CEUS and UE was an effective method to diagnose TI-RADS4 nodules could not be diagnosed by UG-FNAC.