Dual-energy CT in diagnosis of thyroid cartilage invasion of laryngeal carcinoma / 中国医学影像技术

ABSTRACT

Objective: To explore the value of dual-energy CT in detection of thyroid cartilage invasion of laryngeal carcinoma. Methods: Totally 106 patients with laryngeal carcinoma underwent preoperative dual-energy CT enhanced scan. Taken pathology as the gold standard, the diagnostic value of dual-energy CT derived weighted-average image and iodine overlay image combined with weighted-average image in detection of thyroid cartilage invasion were compared. And the objective parameters (the normalized iodine concentration [NIC] and the slope of spectral Hounsfield unit curve [λHU] of the invaded thyroid cartilage and contralateral normal non-ossified thyroid cartilage in arterial phase) were measured to analyze the effectiveness of dual-energy CT derived quantitative parameters in differentiating invaded thyroid cartilage and normal non-ossified thyroid cartilage. Results: Among 106 patients, thyroid cartilage invasion was found in 40 patients. The sensitivity, specificity and accuracy of weighted-average image in diagnosing thyroid cartilage invasion was 75.00% (30/40), 83.33% (55/66) and 80.19% (85/106), while of iodine overlay image combined with weighted-average image was 87.50% (35/40), 95.45% (63/66) and 92.45% (98/106), respectively. NIC and λHU of invaded thyroid cartilage was 0.16±0.05 and 1.92±0.39, respectively, both higher than those of the contralateral normal non-ossified thyroid cartilage (-0.01±0.02, 0.19±0.06; both P<0.05). The critical values of NIC and λHU for distinguishing invaded thyroid cartilage and normal un-ossified thyroid cartilage was 0.05 and 0.71, the AUC were both 0.98, and the sensitivity was 97.50% and 92.50%, the specificity was 92.50% and 97.50%, respectively. Conclusion: NIC and λHU in arterial phase have promising potential in distinguishing thyroid cartilage invasion of laryngeal carcinoma from normal non-ossified thyroid cartilage.