Preliminary Study Of Spectral CT In The Differential Diagnoses Of Thoracic Tumors

PART ? Preliminary Study of Spectral CT in the Detection of metastases of Advanced Non-Small Cell Lung Cancer[Objective]To study the value of spectral CT in the detection of metastases of advanced non-small cell lung cancer.[Materials and Methods]The purpose of this prospective study was to analyze the characteristics of the spectral CT parameters in patients with advanced NSCLC.In all 30 patients,70 metastatic lesions were detected,including lung,pleural,adrenal gland,live,bone,and psoas major,etc.The gemstone spectral imaging(GSI)parameters of iodine-water concentration and spectral curve slope values in varying of keVs were recorded,and the consistency of the GSI parameters in the primary and metastatic tumors was analyzed statistically.[Results]Fifteen sets of spectral curve slope values including X40-100keV,?40-110keV...to ?60-140keVwere selected and calculated in both primary and metastatic lesions.Moderate correlation was found in 10 out of 15 sets of spectral curve slope values,with the r value of 0.502(P<0.05).Strong correlation of spectral curve slope values between the primary tumors and lung/pleural lesions was found in sets of?40-100keV,?40-110keV,?40-120keV,with the r value of 0.692(P<0.05).Correlation was found in iodine concentration values between the primary tumor and metastatic lesions(r=0.504,P<0.05),and a more positive correlation was also found between primary tumor and lung/pleural metastatic lesions(r=0.693,P<0.05),respectively.There is no statistically significant correlation in water concentration(WC)values(P>0.05).[Conclusions]The characteristics of spectral curve slope values in varying keVs and iodine concentrations(IC)are of value in the detection of metastases in advanced patients with NSCLC,however,the value could be limited due to the various sites of metastases.PART ? Spectral CT:Preliminary Study in the Diagnosis of Primary Pleural Tumor[Objective]To study the value of spectral CT in the preoperative diagnosis of primary pleural tumors.[Materials and Methods]Nineteen patients with primary pleural tumors were enrolled.All were performed spectral CT with gemstone spectral imaging(GSI)technique.Clinicopathologic characteristics of each patients were documented.The measurement of CT values of each lesions on images in varying keV was obtained.The GSI parameters of iodine-water concentration and spectral curve slope were recorded.The differences of GSI parameters between the benign and malignant tumors were analyzed.[Result]Malignant tumors were confirmed in 8 cases including solitary fibrous tumors of the pleura(SFTP)of 3,mesothelioma of 3 and synovial sarcoma of 2.Benign tumors were determined in 11 cases including schwannoma of 9,SFTP of 1,lipoma of 1.The measurement of average iodine and water concentration of malignant tumors were(14.05±8.82g/1?1027.32±8.64),which of benign tumors were(6.38±5.33g/l?1016.44±11.94).The curve slope of malignant tumors was(1.40±0.70),and that of benign tumors was(0.85±0.54).The average CT value of malignant tumors was signif[]icantly greater than that of benign tumors on the images obtained with 40-110 keV(P<0.05)[Conclusion]Primary pleural tumors in various etiologies have some characteristics on spectral CT.The combination of conventional CT imaging and spectral parameters is helplful to distinguish benign tumors from malignant tumors.