Objective To evaluate the correlations of emphysema and airway wall thickness to chronic obstructive pulmonary disease(COPD) of airflow limitation by quantitative CT.Methods 40 COPD patients and other 40 normal controls underwent pulmonary function tests and following MSCT exams with inspiration.The square root of wall area of an airway with an internal area of 8 mm2 (Ai8) and the percentage of low attenuation volume(LAV%) of the whole lung and each lobes at the threshold of-950 HU were measured by a software of Thoracic VCAR.The Ai8 between the observation group and the control one was compared using SPSS2.2.The contributions of LAV% and Ai8 to predictions of FEV1/FVC and FEV1% were also evaluated.Results There was a significantly statistical difference in the Ai8 between the observation group and the control one.There were correlations between airflow limitation markers and all of LAV% as well as Ai8 (P<0.05 for all standardized coefficients).Only the Ai8 of right inferior lobar made a significant contribution to airflow limitation in the whole lung bronchus, and the LAV% of each lobes made a stronger contribution to airflow limitation than the Ai8 of right inferior lobe.Conclusion There is a significantly statistical difference in the Ai8 between the observation group and the control one.The LAV% may make a greater contribution to airflow limitation than Ai8 in COPD group.The influential factors of airflow limitation in order were LAV%, Ai8 of right inferior lobe and Ai8 of the other lobes.

Objective To explore the diagnostic value of intravoxel incoherent motion diffusion-weighted imaging(IVIM-DWI)in diagnosis of different pathological types of lung cancer.Methods 45 patients were performed traditional MR and multi-b value DWI scan by GE discovery 750 MR.The values of Slow-ADC,Fast-ADC and ffast measured on a AW4.5 workstation were analyzed between the different pathological types of lung cancers.The correlations between these IVIM-DWI parameters and the serum tumor markers of lung cancer were analyzed.The diagnostic efficiency of these parameters were evaluated by receiver operator characteristic curve (ROC).Results 27 cases NSCLC(13 cases squamous carcinoma;14 cases adenocarcinoma )and 18 cases SCLC were finally included in this study.There were significant differences in Slow-ADC values between SCLC group and NSCLC group (P =0.00),the adenocarcinoma group (P=0.03),the squamous carcinoma group(P=0.01).There were no significant difference in Fast-ADC as well as ffast value between any two groups.The AUC of Slow-ADC value was 0.874.There existed negative correlation between squamous cell carcinoma antigen(SCC-Ag)of squamous carcinoma group and Slow-ADC(r=-0.730).Conclusion The Slow-ADC of IVIM-DWI parameters is useful in differential diagnosis of NSCLC and SCLC,which has the largest diagnostic efficiency.The correlation between SCC-Ag and Slow-ADC value has a certain meaning in diagnosing different pathological types of lung cancers.