Dual-plane taller-than-wide definition for thyroid nodules: comparative analysis across TIRADS

Area of Science:

• Radiology
• Oncology
• Medical Imaging

Background:

• The evaluation of thyroid nodules using ultrasound (US) often involves assessing the taller-than-wide (TTW) shape, but the optimal US plane for this assessment remains debated.
• Different Thyroid Imaging Reporting and Data Systems (TIRADS) exist, each with specific criteria for nodule classification.

Purpose of the Study:

• To compare the diagnostic performance of various TTW ultrasound criteria for thyroid nodule malignancy prediction.
• To identify the optimal TTW criterion across four major TIRADS classifications (Chinese, American, European, Korean).
• To evaluate the utility of TTW criteria in guiding fine-needle aspiration (FNA) biopsy decisions.

Main Methods:

• Retrospective review of preoperative US images from 1125 thyroid nodules.
• Defined four TTW criteria: transverse plane only (T-only), longitudinal plane only (L-only), both planes (Dual-plane), and either one or both planes (Single- or dual-plane).
• Assessed diagnostic performance using area under the receiver operating characteristic curve (AUC) and net reclassification improvement (NRI) for malignancy prediction and FNA guidance.

Main Results:

• The Single- or dual-plane criterion showed the highest AUC (0.813) for malignancy when TTW was used alone.
• Within TIRADS, the Dual-plane criterion achieved the highest AUCs in Chinese (C)-TIRADS (0.884) and European (EU)-TIRADS (0.874).
• Dual-plane also demonstrated improved malignancy reclassification and enhanced FNA guidance in C-TIRADS and American College of Radiology (ACR)-TIRADS.

Conclusions:

• The optimal TTW ultrasound plane selection depends on whether it's used alone or with other suspicious US features.
• Assessing TTW shape in both transverse and longitudinal planes (Dual-plane) provides superior accuracy for malignancy diagnosis and FNA decision-making within TIRADS.
• These findings offer valuable evidence for refining thyroid nodule evaluation guidelines and standardizing biopsy recommendations.