Abstract
OBJECTIVE: To evaluate the relationship between the mean thyroid lobe diameter (MTLD) and the transverse tracheal diameter (TTD), as determined by ultrasound, in order to validate its efficacy as a quantitative marker of goiter. MATERIALS AND METHODS: Thyroid ultrasound images were analyzed. Standardized measurements included the MTLD [(transverse + anteroposterior diameter) ∕ 2], TTD, and thyroid volume [transverse diameter × anteroposterior diameter × length × 0.470]. Statistical correlation and regression analyses were employed to assess the interactions among those variables and their diagnostic utility in goiter detection. RESULTS: A total of 300 thyroid ultrasound images (200 of adults and 100 of children/adolescents) were evaluated. We identified a significant correlation between the MTLD:TTD ratio and goiter. When the MTLD exceeded the normative TTD threshold (> 1.7 cm in adults; > 2.4 cm in children/adolescents), the mean thyroid volume was consistently elevated, in the adult patients-12.5 ± 2.1 mL (normal range, 7-10 mL)-and in the pediatric patients-18.3 ± 3.6 mL (normal range, 5.0-16.1 mL)-confirming goiter (p < 0.001). Regression analysis demonstrated a strong linear relationship between thyroid volume and the MTLD (R² = 0.82; β = 1.34; p < 0.001), with 89% sensitivity and 93% specificity for goiter prediction. An abnormal tracheal index (1.7-2.4 vs. the observed mean of 2.6 ± 0.3) was found to increase diagnostic accuracy (AUC = 0.94; 95% CI: 0.91-0.97). CONCLUSION: The MTLD:TTD ratio is a reliable ultrasound biomarker for goiter detection, demonstrating strong diagnostic performance and volumetric correlation.