Integration of dual-source dual-energy CT quantitative parameters and ultrasound image features: A diagnostic method for extraglandular invasion of papillary thyroid carcinoma.

The present study explored the impact of dual-source dual-energy CT (DECT) quantitative parameters combined with ultrasonography (US) imaging features on the diagnostic value of extrathyroidal extension in papillary thyroid carcinoma (PTC). Analysis was conducted on 136 nodules pathologically confirmed as PTCs in 102 patients who presented to the Affiliated People's Hospital of Jiangsu University (Zhenjiang, China) between January 2018 and August 2023. All patients underwent DECT and US examinations, and the parameters for nodule examination using DECT included iodine concentration, normalized iodine concentration and energy spectrum curve slope. Gemstone spectral imaging (GSI) and US imaging features of extrathyroidal extension (ETE) and non-ETE groups were statistically examined for diagnostic usefulness. A logistic regression model was then constructed and diagnostic performance was assessed using receiver operating characteristics curves. The area under the curve (AUC) for iodine concentration in identifying ETE was 0.722, with the highest accuracy when 2.88 mg/ml was used as the diagnostic threshold. The corresponding sensitivity and specificity were 58.3 and 85.6%, respectively, with a Youden index of 0.44. The AUC for normalized iodine concentration in identifying ETE was 0.713, with the highest accuracy when 0.285 was used as the diagnostic threshold. The corresponding sensitivity and specificity were 65.7 and 78.6%, respectively, with a Youden index of 0.443. The AUC for slope of Hounsfield unit curve in identifying ETE was 0.738, with the highest accuracy when 3.4 was used as the diagnostic threshold. The corresponding sensitivity and specificity were 68.5 and 78.6%, respectively, with a Youden index of 0.471. The AUC of US (maximum longitudinal diameter >5 mm) was 0.712, with the highest accuracy when 3.845 cm was used as the diagnostic threshold. The corresponding sensitivity and specificity were 46.3 and 89.3%, respectively, with a Youden index of 0.356. The AUC for ETE identification using GSI and US morphological parameters was 0.782, with the highest accuracy when 0.762 was used as the diagnostic threshold. The corresponding sensitivity and specificity were 80.6 and 85.7%, respectively, with a Youden index of 0.663. In conclusion, the accuracy of ultrasound combined with GSI parameters in diagnosing ETE of PTC was improved when compared with that of single DECT and ultrasound morphological examinations.