Interaction between the mean diameter of thyroid lobes and the transverse diameter of the trachea: an ultrasonographic marker for goiter

Abstract

Objective: This study ultrasonographically evaluates the relationship between MTLD and TTD, aiming to validate its efficacy as a quantitative goiter marker.
Method: Thyroid ultrasound images were analyzed. Standardized measurements included: MTLD [(transverse + anteroposterior diameter) / 2], TTD, and thyroid volume [(transverse diameter × anteroposterior diameter × length × 0.470)]. Statistical correlation and regression analyses assessed the interaction between these variables and their diagnostic utility in goiter detection.
Results: Ultrasonographic evaluation of 300 thyroid images (200 adults, 100 children) revealed a significant correlation between MTLD and TTD in goiter detection. When mean lobe diameter exceeded TTD (>1.7 cm in adults, >2.4 cm in children), thyroid volume was consistently elevated (adults: 12.5 ± 2.1 mL vs. normal 7–10 mL; children: 18.3 ± 3.6 mL vs. normal 5.0–16.1 mL), confirming goiter (p < 0.001). Regression analysis demonstrated a strong linear relationship (R² = 0.82, β = 1.34, p < 0.001), with 89% sensitivity and 93% specificity for goiter prediction. Abnormal tracheal indices (1.7–2.4 vs. observed 2.6 ± 0.3) further supported diagnostic accuracy (AUC = 0.94, 95% CI: 0.91–0.97).
Conclusion: The MTLD-TTD ratio is a reliable ultrasonographic biomarker for goiter detection, demonstrating strong diagnostic performance and volumetric correlation.