CT quantitative analysis and visual scores of pulmonary alveolar proteinosis and correlation with pulmonary function / 中华放射学杂志

Objective To investigate the evaluating the value of CT quantitative analysis and visual scores on pulmonary alveolar proteinosis (PAP). Methods Thirty one patients with PAP who underwent chest HRCT scans and pulmonary function tests(PFTs)between July 2014 and April 2016 in our hospital were collected and analyzed.HRCT mean lung density(MLD)was measured by syngo InSpace Lung Parenchyma Analysis.Using CT visual scores(HRCT score and RE score),two radiologists with three-years experience at least evaluated pulmonary lesions retrospectively. SPSS 21.0 statistical software was used to analyze the data. Spearman correlation analysis was used to evaluate the correlation between MLD, HRCT score and RE score.The correlation between MLD, HRCT score, RE score, the parameters of PFTs, and blood gas parameters were also analyzed by Spearman correlation analysis. Results There were correlations between MLD,HRCT score and RE score.The correlation coefficient among MLD,HRCT score and RE score were r=0.835 vs r=0.768 vs r=0.838 in baseline. The correlation coefficient among MLD, HRCT score and RE score were r=0.827 vs r=0.780 vs r=0.896 in follow-up. And there were also strong correlation between ΔMLD, ΔHRCTscore and ΔREscore. The correlation coefficient among ΔMLD, ΔHRCTscore and ΔREscore were r=0.599 vs r=0.651 vs r=0.867. There were significantly (P＜0.05) negative correlations among MLD, HRCT score, RE score and VA, DLCO in baseline and follow-up retrospectively. There were significantly (P≤0.001) negative correlations among the ΔMLD, ΔHRCTscore, ΔREscore and ΔVA, ΔDLCO.The correlation among MLD, HRCT score, RE score and DLCO was more significant than that of VA. The correlation among ΔMLD, ΔHRCTscore,ΔREscore and ΔDLCO was more significant than that of ΔVA.There were markedly(P＜0.05) negative correlations between MLD and PO2,and the correlation coefficient were r=-0.738 in baseline vs r=- 0.810 in follow-up. Conclusion The HRCT quantitative analysis and HRCT visual scores are feasible to evaluate PAP.

Effect of Third-generation Dual-source CT Technology on Image Quality of Low-dose Chest CT / 中国医学科学院学报

Objective To evaluate the image quality and radiation dose of third-generation dual-source CT with tin filtration for spectral shaping and iterative reconstructions.Methods Thirty-five patients underwent low-dose CT (LDCT) for lung cancer screening on second-generation dual-source CT and follow-ups on third-generation dual-source CT. Image quality and radiation dose were compared between the two examinations.ResultsThe radiation dose of third-generation dual-source CT [dose-length product (DLP)(49.7±18.2)mGy·cm, effective dose (ED)(0.73±0.26)mSv] was lower than second-generation dual-source CT [DLP (86.37±13.44) mGy·cm, ED(1.20±0.42)mSv](t=6.01, P=0.000;t=6.57, P=0.000). The objective image noise of second-generation dual-source CT [(25.7±2.9)HU] was higher than that of third-generation dual-soure CT[(18.6±4.2)HU](t=5.24,P=0.000).The subjective image noise of second-generation dual-source CT [(4.60±0.49)scores] was significantly lower than that of third-generation dual-source CT [(4.80±0.40)scores] (t=4.15, P=0.000). Conclusion Chest CT for the detection of pulmonary nodules can be performed with third-generation dual-source CT that produces high image quality and low radiation dose when using a stellar infinity detector with spectral shaping.

Application of High-pitch CT Pulmonary Angiography at 70 kV Tube Voltage with 15 ml Contrast Medium Using Third-generation Dual-source CT / 中国医学科学院学报

Objective To assess the application of high-pitch CT pulmonary angiography (CTPA) at 70 kV tube voltage with 15 ml contrast medium using third-generation dual-source CT. Methods A total of 70 patients with clinically suspected pulmonary embolism were randomly divided into two groups: group A (n=35) underwent CTPA on conventional scanning mode (120 kV,80 ml contrast medium);and group B (n=35) underwent CTPA on high-pitch scanning mode at 70 kV tube voltage with 15 ml contrast medium. The CT values and standard deviations of the main pulmonary artery,apical segment of right upper pulmonary lobe (S1),and posterior basal segment of the right lower pulmonary lobe (S10),anterior thoracic air,and back muscles were measured. The signal to noise ratio (SNR),contrast to noise ratio (CNR),and effective dose (ED) were calculated. The overall image quality was evaluated by two blinded radiologists. The quality image was compared using non-parametric test on two independent samples. The potential differences in CT value,SNR,CNR,and ED were analyzed using the independent sample t-test. Results The CT values of main pulmonary artery [(300.62±77.54)HU vs.(332.80±102.80)HU;t=-1.53,P=0.13],S1 [(361.72±84.92)HU vs. (325.37±87.86)HU;t=1.81,P=0.08],and S10 [(359.54±89.61)HU vs. (318.26±87.19)HU;t=2.00,P=0.05] of right lung were not significantly different between group A and group B. The CNR of S1 (22.81±6.05 vs. 19.80±6.60;t=2.05,P=0.04) and S10 (22.65±6.37 vs. 19.28±6.63;t=2.23,P=0.03) of right lung in group A was significantly higher than in group B. The SNR of main pulmonary artery,S1,and S10 of right lung were not significantly different between group A and B. The subjective diagnostic quality values of group A and B were 1 (1,1) and 1 (1,1),respectively (Z=-0.08,P=0.93). The subjective diagnostic quality values evaluated by two radiologists showed excellent consistency(κ=0.87,P=0.01). The mean ED was 79% lower in group B [(0.92±0.23)mSv] than in group A [(4.33±1.80) mSv] (t=11.72,P=0.00).Conclusion Application of high-pitch mode in CTPA at 70 kV with 15 ml contrast medium using third-generation dual-source CT can remarkably reduce radiation dose without affecting image quality.

Influence of new chest CT technologies with low-dose on image quality:an intra-indvidual comparison / 实用放射学杂志

Objective To evaluate retrospectively the image quality and detection of nodules with low-dose chest computed tomography (LDCT)by photon detector and iterative reconstruction (IR).Methods Sixty-six patients with lung nodules underwent routine LDCT with image reconstruction using filtered back projection (FBP).These patients were followed up by LDCT with photon detector 6 months later with image reconstruction using FBP and SAFIRE.Image quality and detection rate of the nodules were compared among groups including routine LDCT,photon decector+FBP and photon Decector+IR groups.Results Noise was decreased and SNR was increased in turn for routine LDCT,photon detector+FBP and photon detector +IR,exhibiting statistical differences (all P0.05).14 ground glass nodules (GGN )in routine LDCT group and 15 in other two groups were identified with the average diameter of (6.44±1.86)mm, (7.23±1.74)mm and (7.31±1.68)mm,respectively.The ability of routine LDCT to detect the GGNs was lower than that of the others.Conclusion Photon detector and IR are able to decrease image noise,improve image quality,and increase detection rate and measurement accuracy of GGN.