The Study Of Optimizing MDCT Scan Technology And The CT Features In Lung Cancer Associated With Thin-walled Airspace

Part One Multi-detector computed tomography features and pathological correlation of peripheral lung cancer associated with thin-walled airspace?Objective? To evaluate multi-detector computed tomography(MDCT)features and pathological basis of lung cancer associated with thin-walled airspace.?Methods? 30 pathologically confirmed lung cancer associated with thin-walled airspace were retrospectively analysed with regard to clinical data,pathological types and MDCT features.For dynamic follow-up CT scans,evaluated the lesion dynamic change.Correlation between the pathological section and CT images were performed in 11 cases.?Results ?There were 30 cases(18 adenocarcinoma,11 squamous carcinoma,1 spindle cell tumor)in total.These features accounted for more than 60% of all MDCT signs,including round shape,irregular inner wall,obulation and septum in airspace in 25cases(83.33%),multiple cysts in 24 cases(80.00%),pleural indentation in 18 cases(60.00%).Blood vessel and bronchus passing through the airspace,bronchus cut-off and ground-glass opacity were significantly different between the thin-walled airspace with solid mixed lesions and lesions without solid(p<0.05).The frequency of bronchus cut-off in solid mixed lesions was higher than that in lesions without solid(82.35% vs.7.70%,p<0.001).The frequency of blood vessel and bronchus passing through the airspace,ground-glass opacity in lesions without solid were higher than that in solid mixed lesions(76.92%vs.35.29%p=0.033;38.46%vs.0%,p=0.009;69.23%vs.5.88%,p<0.001).The pathological basis of the formation of thin-walled airspace was obvious central necrosis of solid lesions and emphysematous change due to the tumor cells diffused along the inner airspace wall and the alveolar wall destruction.Five lesions with progressive wall thickening and increased size of the airspace,and two lesions with decreased size of the airspace and enlarged nodules in followed CT.?Conclusion? The CT manifestations of lung cancer associated with thin-walled airspace were characteristic.The pathological basis of the thin-walled airspace was of variety.Part Two The differential diagnosis study of CT features between thin-walled peripheral lung cancer with air containing space and thin-walled cavitary tuberculosis?Objective?Comparative analysis of the CT features of thin-walled peripheral lung cancer with air containing space and thin-walled cavitary tuberculosis.?Methods? Thirty cases of pathologically confirmed lung cancer associated with thin-walled airspace and twenty-nine cases of pathologically or clinical confirmed thin-walled cavitary tuberculosis were retrospectively analysed with regard to clinical data and MDCT features.The independent-sample t test,Mann-Whitney U-test,Chi-square test and Fisher exact test were used for the statistical analysis.? Results ? No statistical difference was found in sex ratio between the two groups(p>0.05),the mean age of lung cancer group was higher than cavitary tuberculosis group(60.07±10.26 vs 43.41±17.21,p<0.001).The size of lesion(33.08±11.58 vs 21.91± 7.40,p<0.001)and air-containing space(24.17 ± 9.96 vs 15.47 ± 6.98,p<0.001)were greater in lung cancer group compared to cavitary tuberculosis group.The wall thickness of air-containing sapce in lung cancer was less than cavitary tuberculosis group(2.05±0.90 vs 2.50±0.75,p=0.033).There was no statistical difference in location of lesion between the two groups(p>0.05).For morphological patterns,type IV showed mostly in lung cancer group,while type III in cavitary tuberculosis group(p<0.001).The frequency of lobulation,short spiculation,well-defined and smooth interface,multiple air-containing space,vessle passing through the airspace and septum inside airspace and ground-glass opacity in lesions were higher in lung cancer group than that in cavitary tuberculosis group(p<0.05).The frequency of long spiculation,well-defined but coarse interface,cusp angle,satellite 1esions,smooth inner wall were higher in cavitary tuberculosis group than that in lung cancer group(p<0.05).There were no significant differences in the lesion shape,airspace shape,spine-like process,location of airspace in lesion,pleural indentation and pleural adhesion between the two groups(p>0.05).?Conclusion? CT features were different between thin-walled peripheral lung cancer with air containing space and thin-walled cavitary tuberculosis.the signs of lobulation,spiculation,cusp angle,interface,inner wall,internal structure in airspace,ground-glass opacity in lesions and satellite lesions sign contributed to the differential diagnosis of the two diseases.Part Three Diagnostic value of CT target scanning combining with changing position for pulmonary nodule in special location?Objective? To evaluate the diagnostic value of CT target scanning combining with changing position for pulmonary nodules in special location.?Methods? CT target scanning combining with changing position was performed in 22 patients with pulmonary nodules adjacent to heart or in posterior subpleural,which were detected on routine supine CT scanning.Patients with nodules adjacent to heart underwent target spiral CT scanning with lateral position.Target spiral CT scanning with the prone position were performed in patients with posterior subpleural nodules.Subjective and objective analysis of image quality was assessed by 2 experienced chest radiologists.For objective analysis,the signal noise ratio(SNR)and contrast noise ratio(CNR)of lung were calculated.In terms of subjective assessment,the image quality was rated on a3-point scale(0-2)for pulmonary inflation,gravity-dependent pulmonary perfusion and severity of artifacts,respectively.The CT features of pulmonary nodules were compared between different scanning techniques.Moreover,the diagnostic confidence for pulmonary nodules was evaluated.The paired t test,Wilcoxon signed-rank test and Kappa test were used for statistical analysis.?Results? In comparison with conventional supine CT scanning,CT target scanning combining with changing position can improve the subjective image quality scores(p<0.01),increase the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR),show more detailed CT features(p<0.05),and improve the confidence of diagnosis(p<0.01).? Conclusion ? CT target scanning combining with changing position technique can reduce gravity-dependent pulmonary perfusion and heart beat artifacts significantly,have better lung inflation and show detailed features,which should be recommended as the optimal scanning technique for pulmonary nodules adjacent to heart or in posterior subpleural.