Clinical Application Of DSCT Dual Energy Technology In Qualitative Analysis Of Laryngeal Lesions And Preoperative Staging Of Laryngeal Carcinoma

Part ?The value of quantitative parameters of dual-energy CT iodine map indifferentiating benign and malignant lesions of vocal cordObjective:To explore the clinical usefulness of quantitative metrics of dual-energy CT iodine maps in arterial phase in differentiating benign and malignant lesions of vocal cords.Methods:One hundred and twenty-eight patients with vocal cord lesions and underwent DECT enhancement scan before surgery from July 2017 to December 2018 were enrolled.The patients were divided into squamous cell carcinoma group(50 cases),polyp group(50 cases)and chronic inflammation group(28 cases)according to pathological results.Iodine concentration(IC),Normalized iodine concentration(NIC)and Overlay value in arterial phase in three groups were measured and compared.One way ANOVA was used to compare quantitative parameters satisfying normal distribution and with uniform variance,LSD-t test was used for comparison between groups.While those parameters not satisfying normal distribution were compared by Kruskal-Wallis H test.Chi-square was used to compare qualitative parameters.All 128 cases were further divided into benign group(78 cases)and malignant group(50 cases),and the ROC curve was used to analyze the effectiveness of each parameter in differentiating benign and malignant lesions by calculating the areas under the curve(AUC)and the optimal diagnostic thresholds.A p-value less than 0.05 was considered significant.Results:IC,NIC and Overlay value of vocal cord squamous cell carcinoma in arterial phase were higher than those in chronic vocal cord inflammation and vocal cord polyps(P<0.05).The AUCs of IC,NIC and Overlay value in differentiating benign and malignant lesions of vocal cord were 0.933,0.845 and 0.868 respectively(P<0.001).The sensitivity and specificity of diagnosing vocal cord squamous cell carcinoma with IC of 1.75 mg/ml were 98%and 83.3%,respectively.The sensitivity and specificity of diagnosing vocal cord squamous cell carcinoma with NIC of 0.16 were 84%and 76.9%,respectively.And the sensitivity and specificity of diagnosing vocal cord squamous cell carcinoma with Overlay value of 40.15HU were 78%and 91%,respectively.Conclusion:The quantitative parameters of DECT iodine map in artery phase can improve the detection rate of malignant lesions,and have a certain value in the differential diagnosis of benign and malignant vocal cord lesions.Part ?The value of dual-energy CT and MRI in the detection of thyroid cartilageinvasion in laryngeal carcinomaObjective:To investigate the value of dual-energy CT(DECT)and MRI in the evaluation of thyroid cartilage invasion in laryngeal carcinoma.Methods:This study included 106 patients with laryngeal carcinoma who underwent preoperative DECT scan from June 2013 to February 2019,54 of whom underwent MR plain and enhanced examination.With pathological results as the reference standard,the value of DECT in the detection of thyroid cartilage invasion in 106 cases of laryngeal carcinoma was evaluated by subjective evaluation and objective parameters(On the iodine overlay image and energy spectrum image in artery phase,ROI was placed within each invaded thyroid cartilage and contralateral normal nonossified thyroid cartilage to obtain normalized iodine concentration(NIC)and the slope of energy spectrum curve(?HU),then compared these parameters).The value of DECT,MRI,DECT combined with MRI in the diagnosis of thyroid cartilage invasion was further compared in 54 cases who underwent both DECT and MRI examination.Chi-square test was used to compare the counting data,independent sample t-test was used to compare the measurement data,and kappa test was used to compare the consistency among observers.Results:All 106 patients underwent surgery and pathological findings showed that 40 patients had thyroid cartilage invasion.The NIC and ?HU of 35 cases of invaded thyroid cartilage diagnosed correctly by dual-energy CT were 0.16±0.05 and 1.92±0.39,respectively,which were both higher than those of the contralateral normal nonossified thyroid cartilage(-0.01 ±0.02 and 0.19±0.06),(P<0.05).The diagnostic sensitivity,specificity and accuracy of DECT were 87.5%,95.5%and 92.5%,respectively.Of the 54 patients who underwent both DECT and MR examination,20 cases with thyroid cartilage invasion.The sensitivity,specificity and accuracy ofDECT,MRI,DECT combined with MRI in the diagnosis of thyroid cartilage invasion were compared and the results showed that the specificity of DECT was higher than that of MRI(?2=4.221,P<0.05),and there were no statistical differences in the remaining diagnostic indicators(P>0.05).Conclusion:Arterial phase DECT derived NIC and ?HU have a promising potential to distinguish the invaded thyroid cartilage from the normal unossified thyroid cartilage,and DECT showed higher specificity in diagnosing thyroid cartilage invasion in laryngeal carcinoma compared with MRI.Part ?The value of quantitative parameters of dual-energy CT in qualitative evaluation of metastatic lymph nodes in laryngeal carcinomaObjective:To investigate the value of arterial phase dual-energy CT derived iodine concentration(IC)and energy spectrum slope(XHU)in the diagnosis of metastatic cervical lymph nodes of laryngeal carcinoma.Methods:This study included 46 patients with laryngeal carcinoma had complete pathological and dual-energy CT data from October 2014 to February 2019,and 90 lymph nodes were studied retrospectively(including 47 metastatic nodes and 43 non-metastatic nodes).Independent sample t-test was used to compare the differences of IC and ?HU between metastatic and non-metastatic lymph nodes,and between the primary laryngeal lesions and metastatic lymph nodes.ROC curve analysis was performed,and the area under the curve(AUC)and the optimal diagnostic threshold were calculated to analyze the efficacy of the IC and ?HU in the detecting of metastatic cervical lymph nodes.A p-value less than 0.05 was considered as statistically significant.Results:The IC and ?HU of metastatic lymph nodes were 2.29±0.50 mg/ml and 2.38±0.71,which were both significantly higher than those in non-metastatic lymph nodes(1.77±0.48 mg/ml and 1.99±0.63).The AUCs of IC and XHU in diagnosing metastatic lymph nodes were 0.77 and 0.67,respectively(P<0.05).Taking IC of 1.85mg/ml as cutoff value,the sensitivity was 80.9%and the specificity was 65.1%,respectively,while the sensitivity and specificity for the diagnosis of metastatic lymph nodes in laryngeal carcinoma were 57.4%and 72.1%with ?HU=2.15 as cutoff value.There were no difference in IC and ?HU between the primary lesions and the metastatic cervical lymph nodes(P>0.05).Conclusion:Arterial phase DECT derived IC and ?HU have a promising potential to differentiate cervical lymph nodes in laryngeal carcinoma.