Determining the Thyroid Gland Volume Causing Tracheal Compression: A Semiautomated 3D CT Volumetry Study

Abstract

Background and objectives: Increased thyroid gland volume (TV) may bring about tracheal compression, which is one of the causes of respiratory distress. The aim of this study was to investigate the relationship between TV and the severity of tracheal compression independent of patients’ symptoms using semiautomated three-dimensional (3D) volumetry (S3DV) reconstructed from computed tomography (CT) scans. Cut-off TVs leading to different levels of tracheal narrowing were evaluated. Materials and Methods: One hundred sixty-three contrast-enhanced head and neck CT examinations were retrospectively assessed. TVs were measured by S3DV. The degree of tracheal compression was measured at the point where the greatest percent reduction in the cross-sectional area of the trachea adjacent to the thyroid gland was observed. To determine the severity of compression, the tracheal compression ratio (TCR) was defined (TCR = A1 (the narrowest cross-sectional area of trachea)/A2 (the largest cross-sectional area of trachea)). Results: The mean tracheal narrowing was 15% (TCR = 0.85 ± 0.15) in the study population. Patients with more than 15% tracheal compression had significantly higher TV values than those with less than 15% tracheal compression (p < 0.001). In addition, a significant correlation was found between TV and tracheal compression (p < 0.001). Moreover, the receiver operating characteristic (ROC) curve analysis revealed that the cut-off levels for TV that predict a tracheal narrowing of 10%, 20%, 30%, and 40% were 19.75 mL, 21.56 mL, 24.54 mL, and 30.29 mL, respectively (p < 0.05). Conclusions: This study objectively demonstrated that larger thyroid glands cause more severe compression on the trachea. The results may be helpful during the decision-making process for thyroidectomies to be performed due to compression symptoms.

An unexpected cause of a chest pain

“…In presented case the most probable diagnosis was thyroid enlargement. Patient with longstanding goitre, especially substernal, may become symptomatic because of progressive compression of trachea or sudden increase in thyroid volume due to bleeding into the nodule [3]. Our patient complained about pain, but not dyspnoea or dysphagia.…”

CT-based quantitative evaluation of the efficacy after radiofrequency ablation in patients with benign thyroid nodules

“…The current perspective on the use of CT has been mentioned in one of the recent RFA guidelines [14], which recommends CT as 'selectively indicated' for evaluation of the intrathoracic extent of benign thyroid nodules. While there have been studies evaluating the usefulness of CT for thermal ablations in various malignancies [18,19] and for assessing tracheal stenosis [20,21], no study has specifically evaluated the usefulness of CT as an assessment tool between RFA sessions for benign thyroid nodules. Accordingly, the aim of this study was to evaluate the usefulness of CT for quantitative assessment of the neck structures after RFA in patients with benign thyroid nodules.…”