The Ability To Identify Benign And Malignant Lesions In The Lungs Of The Dual-energy Dual-source CT Scanning’s Preliminary Discussion

Part OneDual energy iodine diagram to identify the meaning of benignand malignant lesions to the lungsObjective: To investigate the iodine maps for benign and malignant lunglesions identified and the ability to distinguish different pathological type ofthese diseases.Methods: A retrospective analysis from June2011to January2013,113cases of the dual energy CT scans of patients with lung disease, all lesions hasconfirmed by pathology, biopsy, bronchoscopy.82cases of male,31the female, the age range of18-87years old, mean57.96±10.18years old. In this study, a total of81cases of malignant lesions(32cases of adenocarcinoma of which8cases of poorly differentiatedadenocarcinoma, moderately differentiated adenocarcinoma24cases,squamous carcinoma29cases of which8cases poorly differentiatedsquamous cell carcinoma, moderately differentiated squamous cell carcinoma21cases,9cases of small cell carcinoma and gland spine cell carcinoma in11cases，myofibroblastic tumor in1case, undifferentiated sarcoma1case,carcinosarcoma in1case, mesenchymal malignancies in2cases), benignlesions27cases (12cases of chronic inflammation and inflammatorypseudotumor hyperplasia12cases,2cases were tuberculosis, chondromahamartoma1case).Use German Siemens second generation dual-source CT (SOMATOMDefinition Flash), with dual energy mode (tube voltage is80KV and140KVrespectively,5mm) with a thick layer, using high pressure injector by the elbow at a rate of about3.0ml/s intravenous contrast agent iodine alcohol(300mg/ml), injection quantity for2ml/kg of pulmonary lesions afterinjection of contrast medium25sand90s, then underwent dynamic enhancedscan.at25s scanning range from apex to the end of the lung,90s when thelesions local scan line. According to the pathological type of case study can bedivided into benign and malignant group and benign lesions is divided intobenign rich blood supply and benign lack of blood supply from the group.Send90s images to the post-processing workstation, select "Liver VNC"mode to get iodine maps, measure the iodine content in the lesions and theaorta artery. Select three successive levels of the same size when measuringROI, away from the edge of the lesion, calcification, hollow, artifacts,strengthen blood vessels, etc. the largest possible range includes lesions, usingSPSS13.0software, the data gained by the comparing multiple samples meanvariance analysis. Pairwise comparisons using LSD test ANOVA analysis.Draw ROC (Receiver Operating Characteric) curve, the analysis of theparameter sensitivity and specificity for the diagnosis of pulmonary lesions.Results:1The identification of Malignant group and benign lesion group richblood supply: a benign lesion iodine content was0.424±0.119, andmalignant lesions iodine content of0.274±0.105, malignant iodine content ofless than benign group, the difference was statistically significant (P=0.001<0.05). According to the ROC curve，when taking standardized iodine contentthreshold0.408, the diagnosis of lung cancer sensitivity0.848, specificity of0.667, area under the curve of0.790, a statistically significant difference.2Lack of blood supply groups: TB0.088±0.079, chondroma hamartoma0.3Different types of pulmonary pathology pairwise comparison: theaverage iodine content of squamous cell carcinoma was0.268±0.036,adenocarcinoma average iodine content0.309±0.052, the average iodinecontent in small cell carcinoma was0.245±0.034, the average iodine contentadenoacanthoma cell carcinoma was0.285±0.049. Pairwise comparison P> 0.05, the difference has no statistically significant.4Between different levels of the same histological type of differentiationcomparison: poorly differentiated squamous cell carcinoma squamous0.10±0.03moderately differentiated squamous cell carcinoma squamous0.134±0.031, poorly differentiated adenocarcinoma0.079±0.034, moderatelydifferentiated adenocarcinoma0.136±0.032.Each group P>0.05, thedifference has no statistically significant.Conclusion:1Dual-source CT iodine maps has strong ability to distinguish of benignrich blood supply within the lung lesions and malignant lesions, when lesionsof iodine standardized threshold is less than0.408, the sensitivity of thediagnosis of lung cancer is higher.2For different types and varying degrees of differentiation between thestandardization of lung cancer although no significant difference in iodinecontent, but the iodine content of various types of lesions are different, it canprovide some reference value, depending on its value for clinical diagnosis. Part TwoSpectrum curve of the significance of lung benign and malignantlesions identifiedObjective: To investigate the dual-energy spectrum curve fordiscriminating benign and malignant lung lesions and the ability to distinguishdifferent types of pathology.Methods: The same to part one. Send the90s dual-energy image data tothe workstation of Dual-Energy software, select "Monoenergetic" mode 10Kev intervals in the40-190Kev split into16Kev different energy levels, Theresulting image is saved, and use of Spectroscopy software drawing spectrumcurve，After the designated area of interest, then obtain its spectrum curveand the CT values of the lesion under different Kev, ROI measurement shouldbe avoided the opening edge of lesions, calcification, necrosis, artifacts,enhanced blood vessels.Results:1The comparison of benign and malignant lesions: spectrum curve of thepathological changes of malignant and benign lesions contorts the generaltrend is consistent, with the increase of Kev gradually reduce the pathologicalchanges of CT values, under the low energy (40-70Kev) both curve isrelatively steep,80-110Kev both almost parallel, minimum difference in120-190Kev, or even overlapping.The slope of malignant lesions K=1.94±0.72, slope benign lesions K=2.70±0.91, P <0.05, the difference was statistically significant. ROC curveplotted on the slope K derived, when the slope K <2.17, the sensitivity ofdiagnosis of lung cancer was0.687, the specific degree is0.778, area underthe curve is0.753.2For pairwise comparisons of different pathological type of lungcancer group: all lesions similar contorts the trend of the energy spectrumcurve, with the increase of Kev, lesions showed a trend of gradual reduction ofCT values, by calculating the slope of each group K, adenocarcinoma slope K=2.10±0.25adenoacanthoma cell carcinoma slope K=1.80±0.50,squamous cell carcinoma of the slope K=2.08±0.99, small cell carcinoma ofthe slope K=1.59±0.47, P＞0.05，For pairwise comparison,there was nostatistically significant difference between groups.Conclusions:1The presence of benign and malignant lesions of the lungs dual-energyspectrum curve has some difference, the slope of the curve is less than2.17when the spectrum diagnosis of lung cancer is relatively high specificity.2Tuberculoma spectrum curve of the trend line is different from other types of pathological changes, so easy to distinguish between the differentialdiagnosis of tuberculoma.3Spectral curve slope on different kinds of pathological changes and thedegree of differentiation to distinguish the difference have no sense ofstatistics, but different pathological changes the value of the slope, also isdifferent, can according to the size of its value for the type to give promptdiagnosis significance.