Collateral Ventilation Quantification Using Xenon-Enhanced Dynamic Dual-Energy CT: Differences between Canine and Swine Models of Bronchial Occlusion

Objective

The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT.

Materials and Methods

Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model.

Results

A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 ± 5.0 Hounsfield units [HU] vs. -2.8 ± 7.1 HU, p = 0.001; normalized percentage difference, -79.8 ± 1.8% vs. -5.4 ± 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892).

Conclusion

Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.     

Assessment of the Right Ventricular Function and Mass Using Cardiac Multi-Detector Computed Tomography in Patients with Chronic Obstructive Pulmonary Disease

Objective

We wanted to assess the relationship between measurements of the right ventricular (RV) function and mass, with using cardiac multi-detector computed tomography (MDCT) and the severity of chronic obstructive pulmonary disease (COPD) as determined by the pulmonary function test (PFT).

Materials and Methods

Measurements of PFT and cardiac MDCT were obtained in 33 COPD patients. Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, the patients were divided into three groups according to the severity of the disease: stage I (mild, n = 4), stage II (moderate, n = 15) and stage III (severe, n = 14). The RV function and the wall mass were obtained by cardiac MDCT. The results were compared among the groups using the Student-Newman-Keuls method. Pearson''s correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and the wall mass results with the PFT results. P-values less than 0.05 were considered statistically significant.

Results

The RVEF and mass were 47±3% and 41±2 g in stage I, 46±6% and 46±5 g in stage II, and 35±5% and 55±6 g in stage III, respectively. The RVEF was significantly lower in stage III than in stage I and II (p < 0.01). The RV mass was significantly different among the three stages, according to the disease severity of COPD (p < 0.05). The correlation was excellent between the MDCT results and forced expiratory volume in 1 sec (r = 0.797 for RVEF and r = -0.769 for RV mass) and forced expiratory volume in 1 sec to the forced vital capacity (r = 0.745 for RVEF and r = -0.718 for RV mass).

Conclusion

Our study shows that the mean RV wall mass as measured by cardiac MDCT correlates well with the COPD disease severity as determined by PFT.     

医院对COPD稳定期患者行无创通气的适用性研究

目的探讨稳定期慢性阻塞性肺疾病（COPD）患者行无创通气的治疗效果。方法选择稳定期慢性阻塞性肺疾病患者30例分为两组,实验组12例,对照组18例。对照组采用常规治疗,实验组在常规治疗基础上加无创通气呼吸机治疗,4h／d。结果实验组与对照组比较,两组治疗前呼吸困难评分、6分钟步行实验、圣乔治评分没有统计学差异,P〉0．05,治疗后P〈0．05,两组差别显著,实验组好于对照组。结论稳定期COPD患者医院行无创通气有较好临床效果。     

慢性阻塞性肺部病变患者肺部CT灌注成像特征

目的探讨慢性阻塞性肺疾病(COPD)患者肺部CT灌注成像的时间密度曲线(TDC)和灌注参数特征。方法共44例,分为COPD组25例及对照组19例。均行肺部多层螺旋CT(MSCT)动态增强扫描。图像经后处理,设定感兴趣区(右腹肺、右背肺和左腹肺、左背肺),得到各处肺组织TDC和灌注参数,包括灌注值(P),强化峰值增量(PEI),达峰值时间(TTP)和血容量(BV)。比较分析COPD组和对照组的TDC特征,以及各灌注参数的差异性。结果COPD组较对照组TDC波峰延后。各灌注参数腹背肺比率在2组无显著性差异(P>0.05)。COPD组TTP较对照组明显延长(P=0.010)。P、PEI和BV在2组无显著性差异(P>0.05)。结论CT灌注成像显示COPD患者肺部血流灌注异常主要表现为TDC波峰延后,TTP延长。     

慢性阻塞性肺疾病病人机械通气时内源性呼气末正压测定

目的：测定慢性阻塞性肺疾病（ＣＯＰＤ）患者机械通气时的内源性呼气末正压（ＰＥＥＰｉ）。方法：应用呼气末阻断法测定了３６例ＣＯＰＤ患者机械通气时的ＰＥＥＰｉ。结果：１５例中度ＣＯＰＤ病人中的７例和２１例重度ＣＯＰＤ病人中的１８例存在ＰＥＥＰｉ。两组间Ｐ＜０．０１。结论：ＣＯＰＤ病人机械通气时应常规测量ＰＥＥＰｉ，加强气道管理，调整通气模式和参数，可提高通气治疗疗效。     

西宁地区老年慢性阻塞性肺疾病患者营养状况与生活质量的关系

目的：研究西宁地区老年慢性阻塞性肺疾病患者营养状况与生活质量的关系。方法：对328名60岁以上老人采用微型营养评定量表（MNA）进行营养状况调查。根据营养评价结果分为营养正常组和营养不良组,两组进行生活质量测定,观察指标包括：生活自理能力测定（ALD）、老年抑郁量表（GDS）、社会支持量表（SSRS）。结果：328例患者中,182例患者营养状况良好,占55.5%;146例患者为营养不良,占44.5%。营养不良组的ADL（25.10±10.85）分、GDS（6.03±3.14）分、SSRS（35.43±5.82）分,均低于营养良好组ADL（19.76±8.00）分、GDS（4.40±2.32）分、SSRS（38.70±6.36）分,差异有统计学意义（P〈0.05）。结论：老年COPD患者营养状况与生活质量密切相关,提高老年人生活自理能力、抑郁状况、社会支持水平,缩短住院时间,可以改善老年患者生存质量。     

Quantitative Computed Tomography of Pulmonary Emphysema and Ventricular Function in Chronic Obstructive Pulmonary Disease Patients with Pulmonary Hypertension

Objective

This study strived to evaluate the relationship between degree of pulmonary emphysema and cardiac ventricular function in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension (PH) using electrocardiographic-gated multidetector computed tomography (CT).

Materials and Methods

Lung transplantation candidates with the diagnosis of COPD and PH were chosen for the study population, and a total of 15 patients were included. The extent of emphysema is defined as the percentage of voxels below -910 Hounsfield units in the lung windows in whole lung CT without intravenous contrast. Heart function parameters were measured by electrocardiographic-gated CT angiography. Linear regression analysis was conducted to examine the associations between percent emphysema and heart function indicators.

Results

Significant correlations were found between percent emphysema and right ventricular (RV) measurements, including RV end-diastolic volume (R² = 0.340, p = 0.023), RV stroke volume (R² = 0.406, p = 0.011), and RV cardiac output (R² = 0.382, p = 0.014); the correlations between percent emphysema and left ventricular function indicators were not observed.

Conclusion

The study revealed that percent emphysema is correlated with RV dysfunction among COPD patients with PH. Based on our findings, percent emphysema can be considered for use as an indicator to predict the severity of right ventricular dysfunction among COPD patients.     

New Method for Combined Quantitative Assessment of Air-Trapping and Emphysema on Chest Computed Tomography in Chronic Obstructive Pulmonary Disease: Comparison with Parametric Response Mapping

ObjectiveEmphysema and small-airway disease are the two major components of chronic obstructive pulmonary disease (COPD). We propose a novel method of quantitative computed tomography (CT) emphysema air-trapping composite (EAtC) mapping to assess each COPD component. We analyzed the potential use of this method for assessing lung function in patients with COPD.Materials and MethodsA total of 584 patients with COPD underwent inspiration and expiration CTs. Using pairwise analysis of inspiration and expiration CTs with non-rigid registration, EAtC mapping classified lung parenchyma into three areas: Normal, functional air trapping (fAT), and emphysema (Emph). We defined fAT as the area with a density change of less than 60 Hounsfield units (HU) between inspiration and expiration CTs among areas with a density less than −856 HU on inspiration CT. The volume fraction of each area was compared with clinical parameters and pulmonary function tests (PFTs). The results were compared with those of parametric response mapping (PRM) analysis.ResultsThe relative volumes of the EAtC classes differed according to the Global Initiative for Chronic Obstructive Lung Disease stages (p < 0.001). Each class showed moderate correlations with forced expiratory volume in 1 second (FEV₁) and FEV₁/forced vital capacity (FVC) (r = −0.659–0.674, p < 0.001). Both fAT and Emph were significant predictors of FEV₁ and FEV₁/FVC (R² = 0.352 and 0.488, respectively; p < 0.001). fAT was a significant predictor of mean forced expiratory flow between 25% and 75% and residual volume/total vital capacity (R² = 0.264 and 0.233, respectively; p < 0.001), while Emph and age were significant predictors of carbon monoxide diffusing capacity (R² = 0.303; p < 0.001). fAT showed better correlations with PFTs than with small-airway disease on PRM.ConclusionThe proposed quantitative CT EAtC mapping provides comprehensive lung functional information on each disease component of COPD, which may serve as an imaging biomarker of lung function.     

剑鞘气管与慢性阻塞性肺疾病的关系

研究剑鞘气管与慢性阻塞性肺疾病之间的关系。材料与方法搜集１９９６－１９９８年有剑鞘气管和ＣＯＰＤ的患者７０例。胸部轴位ＣＴ用１０ｍｍ层厚连续扫描。在主动脉弓上方１０ｍｍ层面测量气管的内冠状径和内矢状径。剑鞘形状的程度用内冠状径与内矢状径的比较来表示。     

The effects of dynamic hyperinflation on CT emphysema measurements in patients with COPD

ObjectivesDynamic hyperinflation (DH) significantly affects dyspnea and intolerance to exercise in patients with chronic obstructive pulmonary disease (COPD). Quantitative computed tomography (QCT) of the chest is the modality of choice for quantification of the extent of anatomical lung damage in patients with COPD. The purpose of this article is to assess the effects of DH on QCT measurements.MethodsThe study sample comprised patients with Global initiative for Chronic Obstructive Lung Disease (GOLD) stages III and IV COPD referred for chest CT. We examined differences in total lung volume (TLV), emphysema volume (EV), and emphysema index (EI) determined by QCT before and after DH induction by metronome-paced tachypnea (MPT). Initial (resting) and post-MPT CT examinations were performed with the same parameters.ResultsImages from 66 CT scans (33 patients) were evaluated. EV and EI, but not TLV, increased significantly (p < 0.0001) after DH induction.ConclusionQCT showed significant increases in EV and EI after MPT-induced DH in patients with GOLD stages III and IV COPD. For longitudinal assessment of patients with COPD using QCT, we recommend the application of a pre-examination rest period, as DH could mimic disease progression. QCT studies of the effects of DH-preventive therapy before exercise could expand our knowledge of effective measures to delay DH-related progression of COPD.     

综合干预措施对慢性阻塞性肺病的临床意义

目的探讨综合干预措施对慢性阻塞性肺病的临床价值。方法将100例符合COPD诊断标准的患者随机分成两组。一组采用综合干预措施(包括COPD知识的定期咨询和宣传教育,流感疫苗,肺炎疫苗的接种。同时吸入布地奈德400μg/d,福莫特罗9~18μg/d,及必要的家庭氧疗)。另一组常规处理(对照组)。结果干预组的住院率由干预前19.5%下降至5.5%(P<0.05),而对照组则无明显下降。干预组患者急性加重住院时间(11.5±5)d,而对照组则为(20.4±3)d,两组相比差异有统计学意义(P<0.05)。干预组戒烟40例(80%),对照组只有10例(20%),两组比较有统计学差异(P<0.05)。干预组生活质量评分低于对照组,两组比较差异有统计学意义(P<0.05)。结论对COPD患者进行综合干预有重要临床意义。     

慢性阻塞性肺病急性加重患者膈肌影像变化

目的 研究慢性阻塞性肺病(COPD)急性加重患者膈肌影像变化,为选择合适的肺康复方式提供参考.方法 36例COPD急性加重患者行平板数字化X线摄影系统和肺功能检查,组间差异分析采用单因素方差分析,膈肌移动度与残气量之间采用Peanon相关分析.结果 GOLD 2级与GOLD 4级患者膈肌移动度和膈肌角度之间有显著性差异.膈肌移动度与残气量为负相关(r=-0.82,P=0.003).结论 平板数字化X线摄影膈肌参数与肺功能检查结果之间有很好的相关性,可用于评估患者肺功能.     

Lung Nodule Detection on Chest CT: Evaluation of a Computer-Aided Detection (CAD) System

Objective

To evaluate the capacity of a computer-aided detection (CAD) system to detect lung nodules in clinical chest CT.

Materials and Methods

A total of 210 consecutive clinical chest CT scans and their reports were reviewed by two chest radiologists and 70 were selected (33 without nodules and 37 with 1-6 nodules, 4-15.4 mm in diameter). The CAD system (ImageChecker® CT LN-1000) developed by R2 Technology, Inc. (Sunnyvale, CA) was used. Its algorithm was designed to detect nodules with a diameter of 4-20 mm. The two chest radiologists working with the CAD system detected a total of 78 nodules. These 78 nodules form the database for this study. Four independent observers interpreted the studies with and without the CAD system.

Results

The detection rates of the four independent observers without CAD were 81% (63/78), 85% (66/78), 83% (65/78), and 83% (65/78), respectively. With CAD their rates were 87% (68/78), 85% (66/78), 86% (67/78), and 85% (66/78), respectively. The differences between these two sets of detection rates did not reach statistical significance. In addition, CAD detected eight nodules that were not mentioned in the original clinical radiology reports. The CAD system produced 1.56 false-positive nodules per CT study. The four test observers had 0, 0.1, 0.17, and 0.26 false-positive results per study without CAD and 0.07, 0.2, 0.23, and 0.39 with CAD, respectively.

Conclusion

The CAD system can assist radiologists in detecting pulmonary nodules in chest CT, but with a potential increase in their false positive rates. Technological improvements to the system could increase the sensitivity and specificity for the detection of pulmonary nodules and reduce these false-positive results.     

Feasibility of Automated Quantification of Regional Disease Patterns Depicted on High-Resolution Computed Tomography in Patients with Various Diffuse Lung Diseases

Objective

This study was designed to develop an automated system for quantification of various regional disease patterns of diffuse lung diseases as depicted on high-resolution computed tomography (HRCT) and to compare the performance of the automated system with human readers.

Materials and Methods

A total of 600 circular regions-of-interest (ROIs), 10 pixels in diameter, were utilized. The 600 ROIs comprised 100 ROIs that represented six typical regional patterns (normal, ground-glass opacity, reticular opacity, honeycombing, emphysema, and consolidation). The ROIs were used to train the automated classification system based on the use of a Support Vector Machine classifier and 37 features of texture and shape. The performance of the classification system was tested with a 5-fold cross-validation method. An automated quantification system was developed with a moving ROI in the lung area, which helped classify each pixel into six categories. A total of 92 HRCT images obtained from patients with different diseases were used to validate the quantification system. Two radiologists independently classified lung areas of the same CT images into six patterns using the manual drawing function of dedicated software. Agreement between the automated system and the readers and between the two individual readers was assessed.

Results

The overall accuracy of the system to classify each disease pattern based on the typical ROIs was 89%. When the quantification results were examined, the average agreement between the system and each radiologist was 52% and 49%, respectively. The agreement between the two radiologists was 67%.

Conclusion

An automated quantification system for various regional patterns of diffuse interstitial lung diseases can be used for objective and reproducible assessment of disease severity.     

苏子降气汤治疗慢阻肺的肺功能观察

目的：对苏子降气汤治疗慢阻肺的肺功能的临床疗效进行探讨。方法随机抽取2011年10月～2013年12月治疗的60例慢性阻塞性肺疾病患者,分为对照组与观察组,对照组患者使用西医常规进行治疗,观察组患者使用苏子降气汤进行治疗,对两组患者的临床疗效进行对比与分析。结果观察组患者的治疗有效率明为96．7％,对照组为73．3％,存在较大差异,具备统计学意义（ P＜0．05）。两组患者在接受治疗后, FEV1、FVC、FEV1／FVC均明显改善,且观察组优于对照组,存在较大差异,具备统计学意义（ P＜0．05）。结论苏子降气汤在慢性阻塞性肺病治疗中的应用,有效提高了患者的临床治疗有效率,改善患者的肺功能,抑制细菌的滋生,缩短药力的输送与发挥药效时间,临床使用价值较高。     

慢性阻塞性肺疾病的肺高分辨率CT呼气相研究

目的　分析慢性阻塞性肺疾病 (COPD)患者吸气相和呼气相高分辨率CT(HRCT)表现 ,对呼气相HRCT上的空气潴留征进行定量分析。方法　 44例COPD患者进行吸气相、呼气相HRCT和肺功能试验检查 ,分析其HRCT表现 ,统计双肺吸 -呼气相密度差值 (VD)和面积缩小率 (AD)、空气潴留评分值并与肺功能试验指标进行相关性分析。结果　 40例患者呼气相HRCT上出现空气潴留征 ,超出了吸气相异常征象的范围 ;双肺VD和AD、空气潴留评分值与肺功能试验指标显著相关 (Ρ <0 .0 5 )。结论　呼气相HRCT可以作为吸气相HRCT的补充手段 ,空气潴留征能够定量分析并且反映患者的肺功能状况     

多层螺旋CT肺气肿指数评估慢性阻塞性肺疾病的肺叶功能

目的 探讨多层螺旋CT (MSCT)肺气肿指数(EI)评估慢性阻塞性肺疾病(COPD)患者肺叶功能的价值.资料与方法 30例临床确诊的COPD患者(研究组)和34例CT胸部体检且肺功能正常者(对照组)均行MSCT及临床肺功能检查.测量肺容积、肺气肿容积(EV)、EI,分析全肺及肺叶EI与第1秒用力肺活量实测值与预测值百分比(FEV1％)、第1秒用力肺活量/用力肺活量(FEV1/FVC)的相关性,比较两组各肺叶EI总和与全肺EI之间的差异.结果 研究组呼吸两相各肺叶及全肺EI均显著高于对照组(P＜0.05);研究组深吸气相右肺上叶EI值与FEV1/FVC呈正相关(r=0.400,P＜0.05),其他肺叶及全肺EI值与FEV1％(r=-0.693～-0.498,P＜0.05)、FEV1/FVC(r=-0.765 ～-0.353,P＜0.05)呈负相关;深呼气相各肺叶及全肺EI值与FEV1％(r=-0.729～-0.473,P＜0.05)、FEV1/FVC(r=-0.769～-0.353,P＜0.05)均呈负相关.结论 MSCT测量全肺及各肺叶EI值与肺功能指标有一定的相关性,采用EI值能够判断COPD患者全肺及肺叶的损伤程度及功能.     

Variability of bronchial measurements obtained by sequential CT using two computer-based methods

This study aimed to evaluate the variability of lumen (LA) and wall area (WA) measurements obtained on two successive MDCT acquisitions using energy-driven contour estimation (EDCE) and full width at half maximum (FWHM) approaches. Both methods were applied to a database of segmental and subsegmental bronchi with LA > 4 mm² containing 42 bronchial segments of 10 successive slices that best matched on each acquisition. For both methods, the 95% confidence interval between repeated MDCT was between –1.59 and 1.5 mm² for LA, and –3.31 and 2.96 mm² for WA. The values of the coefficient of measurement variation (CV₁₀, i.e., percentage ratio of the standard deviation obtained from the 10 successive slices to their mean value) were strongly correlated between repeated MDCT data acquisitions (r > 0.72; p < 0.0001). Compared with FWHM, LA values obtained using EDCE were higher for LA < 15 mm², whereas WA values were lower for bronchi with WA < 13 mm²; no systematic EDCE underestimation or overestimation was observed for thicker-walled bronchi. In conclusion, variability between CT examinations and assessment techniques may impair measurements. Therefore, new parameters such as CV₁₀ need to be investigated to study bronchial remodeling. Finally, EDCE and FWHM are not interchangeable in longitudinal studies.     

无创呼吸机联合纳洛酮治疗慢性阻塞性肺疾病并发Ⅱ型呼吸衰竭的效果分析

目的探讨无创呼吸机联合纳洛酮治疗慢性阻塞性肺疾病并发Ⅱ型呼吸衰竭的临床效果。方法将我院2009年10月～2010年7月收治的慢性阻塞性肺疾病并发Ⅱ型呼吸衰竭患者85例,随机分为观察组(n=43)和对照组(n=42)。对照组患者采用常规方法治疗,观察组加用无创呼吸机联合纳洛酮治疗,比较两组患者的临床效果。结果观察组的总有效率为97.7%,对照组为81.0%,两组有显著性差异(P<0.05);治疗后观察组PaO2、SpO2显著高于对照组(P<0.05),PaCO2显著低于对照组(P<0.05)。结论无创呼吸机联合纳洛酮治疗慢性阻塞性肺疾病并发Ⅱ型呼吸衰竭的效果满意,值得推广。