Lung Attenuation Research Articles

Quantitative computed tomography for the prediction of pulmonary function after lung cancer surgery: a simple method using simulation software☆

The prediction of pulmonary functional reserve is mandatory in therapeutic decision-making for patients with resectable lung cancer, especially those with underlying lung disease. Volumetric analysis in combination with densitometric analysis of the affected lung lobe or segment with quantitative computed tomography (CT) helps to identify residual pulmonary function, although the utility of this modality needs investigation. The subjects of this prospective study were 30 patients with resectable lung cancer. A three-dimensional CT lung model was created with voxels representing normal lung attenuation (-600 to -910 Hounsfield units). Residual pulmonary function was predicted by drawing a boundary line between the lung to be preserved and that to be resected, directly on the lung model. The predicted values were correlated with the postoperative measured values. The predicted and measured values corresponded well (r=0.89, p<0.001). Although the predicted values corresponded with values predicted by simple calculation using a segment-counting method (r=0.98), there were two outliers whose pulmonary functional reserves were predicted more accurately by CT than by segment counting. The measured pulmonary functional reserves were significantly higher than the predicted values in patients with extensive emphysematous areas (<-910 Hounsfield units), but not in patients with chronic obstructive pulmonary disease. Quantitative CT yielded accurate prediction of functional reserve after lung cancer surgery and helped to identify patients whose functional reserves are likely to be underestimated. Hence, this modality should be utilized for patients with marginal pulmonary function.

Role of MCP-1 in endotoxemia and sepsis

Sepsis is a complex clinical syndrome resulting from a harmful host inflammatory response to infection. Similarly, lipopolysaccharide (LPS) induced endotoxemia is marked by the activation of inflammatory responses, which can lead to shock, multiple organ damage and even death. Inflammatory mediator, chemokines are known to play an important role in the pathogenesis of sepsis and endotoxemia. Monocyte chemoattractant protein (MCP)-1, a prototype of CC chemokines, is a potent chemoattractant and a regulatory mediator involved in a variety of inflammatory diseases. The objective of this study is to investigate the role of MCP-1, by using bindarit, a blocker of MCP-1 synthesis, in murine models of sepsis and endotoxemia. Treatment with bindarit both prophylactically and therapeutically significantly ( P < 0.05) reduced MCP-1 levels in the lungs and liver in both sepsis and endotoxemia. In addition, prophylactic and therapeutic treatment with bindarit significantly ( P < 0.05) protected mice against sepsis and endotoxemia, as evidenced by the attenuation in lung and liver myeloperoxidase (MPO) activity, an indicator of neutrophil recruitment. The protective effect of bindarit was further confirmed by histological examination of lung and liver sections. Treatment with bindarit reduced lung and liver injury as indicated by decreased thickening of alveolar and neutrophil infiltration in CLP-induced sepsis and LPS-induced endotoxemia. Considering these results, we propose that anti-MCP-1 strategies may be of potential therapeutic value in the treatment of sepsis and endotoxemia.

Longitudinal study of airway dimensions in chronic obstructive pulmonary disease using computed tomography

Chest CT has been widely used for the evaluation of structural changes in lung parenchyma and airways in cross-sectional studies. There has been no report on the annual changes in airway dimensions as assessed by CT in COPD patients. The objective of this study was to investigate the annual changes in airway dimensions and lung attenuation using CT in patients with COPD and to evaluate the correlations among annual changes in CT measurements and pulmonary function. Eighty-three men with COPD had completed five annual assessments of CT scans and pulmonary function tests over 4 years. Airway dimensions of the basal segment bronchi and lung attenuation on CT images were analysed in 38 subjects in whom the same airway could be measured at least three times, including at entry and at the end of the study. Mean annual decline in FEV(1) was 21 mL/year. Annual changes in the percentage of low attenuation areas were not significantly correlated with decline in FEV(1). On the other hand, annual changes in the percentage of wall area (WA%/year) were significantly inversely correlated with annual changes in FEV(1) (r = -0.363, P = 0.025), whereas WA%/year did not differ among severity stages at entry and did not correlate with baseline FEV(1). The results showing that annual changes in airway thickening correlated with annual decline in air flow limitation suggests the importance of treatment of airway inflammation in COPD. CT is a useful tool for quantitative estimation not only of emphysema but also of airway lesions in longitudinal studies.

Idiopathic Pulmonary Fibrosis: Physiologic Tests, Quantitative CT Indexes, and CT Visual Scores as Predictors of Mortality

To retrospectively evaluate quantitative computed tomographic (CT) indexes, pulmonary function test results, and visual CT scoring as predictors of mortality and to describe serial changes in quantitative CT indexes over 12 months in patients with idiopathic pulmonary fibrosis (IPF). Institutional review board approval and informed consent were obtained at all participating institutions. One hundred sixty-seven patients (110 men, 57 women; mean age, 63 years +/- 9 [standard deviation]) with IPF were enrolled in a clinical trial. Patients underwent thin-section CT in the supine position at full inspiration at enrollment (baseline) and at 12-month follow-up. After segmentation of the lungs, mean lung attenuation (MLA), skewness, and kurtosis were measured. Extent of ground glass opacity and lung fibrosis were assessed visually. Forced vital capacity (FVC) and total lung capacity (TLC) were measured. Median duration of follow-up for mortality was 1.5 years. Univariate and multivariate survival analyses were used to determine the predictive value of baseline variables for survival. At univariate analysis, baseline variables predictive of death included TLC, fibrosis, skewness, and kurtosis. At multivariate analysis, FVC (P = .006) and fibrosis (P = .002) were predictors of short-term mortality. In 95 patients who had both baseline and follow-up CT scans, fibrosis (P = .030), MLA (P = .003), skewness (P < .001), and kurtosis (P < .001) all showed change indicating disease progression. Visually determined disease extent on CT images is a strong independent predictor of mortality in IPF. Serial evaluation of quantitative CT measures can show disease progression in these patients.

Correlation between Expiratory Increase of Lung Attenuation and Age and Smoking in the Subjects with Normal Inspiratory Low Dose CT and Pulmonary Function Test

Background: The attenuation of the lung parenchyma increases on expiration as a consequence of decreased air in the lung. Expiratory CT scans have been used to show air trapping in patients with chronic airway disease and diffuse parenchymal disease and also in asymptomatic smokers. Although there have been several reports investigating the regional air trapping on a expiratory CT scan, there have been only a few reports evaluating the changes of whole lung attenuation with considering its clinical significance, and especially in healthy subjects. The purpose of this study was to evaluate the correlation of an expiratory increase of lung attenuation with age and smoking in healthy subjects. Methods: Asymptomatic subjects who underwent a low dose chest CT scan as part of a routine check-up and who showed normal spirometry and a normal inspiratory CT scan were recruited for this study. We excluded the subjects with significant regional air trapping seen on their expiratory CT scan. Lung attenuation was measured at 24 points of both the inspiratory and expiratory CT scans, respectively, for 100 subjects. The correlations between an expiratory increase of the lung attenuation and the amount of smoking, the patient's age and the results of spirometric test were assessed. Results: There were 87 men and 13 women included in this study. Their median age was 49.0 years old (range:25~71). Sixty current smokers, 24 ex-smokers and 16 non-smokers were included. As age increased, the expiratory increase of lung attenuation was reduced at every measuring points (r=-0.297~-0.487, Pearson correlation). The statistical significance was maintained after controlling for the effect of smoking. Smoking was associated with a reduction of the expiratory increase of lung attenuation. But the significance was reduced after controlling for the patient's age. The , FVC, and were not associated with an expiratory increase of lung attenuation. Conclusion: The expiratory increase of lung attenuation in subjects with a normal inspiratory CT scan was negatively correlated with age. It was also reduced in heavy smokers. It may reflect aging and the smoking related changes.

Localized-Low Attenuation of the Lung on Thin-Section CT in Experimentally Induced Pulmonary Arterial Occlusion with Balloon Catheter in Pigs

Purpose: To determine whether a localized low-attenuation (LLA) is induced on a thinsection CT (TSCT) during an acute pulmonary arterial occlusion in pigs. Materials and Methods: In eight pigs, 14 sites of the descending pulmonary artery were obstructed using balloon catheters. The lung TSCTs were obtained immediately after pulmonary artery obstruction (n=13), 10 min (n=10), 30 min (n=14) and 60 min (n=14) after pulmonary artery obstruction at the end of expiration. The TSCTs were also obtained after balloon-deflation at the end of expiration (n=11) and with the balloon-reinflation at inspiration (n=6). Results: Of the 14 sites of pulmonary artery obstruction, 11 (79%) showed LLA. However, LLA progressively became fainter or disappeared on a follow-up CT in seven sites. When the balloon was deflated, 10 of the 11 sites measured showed no change in lung attenuation. After full inspiration, LLA disappeared in three of the six sites. The corresponding areas of LLA on the CT showed a statistically significant increase compared to the baseline CT immediately after inflation (p = 0.021) and 30 minutes after inflation (p =0.041), and after balloon deflation (p =0.036). Conclusion: LLA was induced by acute pulmonary artery obstruction. However, LLA, gradually faded over the 60 minutes following obstruction. LLAs were maintained despite the restoration of pulmonary arterial flow, but disappeared as a result of a full inspiration. Thus, LLA might be caused by air trapping.

Heterogeneity of bronchoconstriction does not distinguish mild asthmatic subjects from healthy controls when supine

Heterogeneity is a fundamental property of airway constriction; however, whether it is a distinguishing feature of mild asthma is not clear. We used computerized tomography and the forced oscillation technique to compare lung heterogeneity between 18 mildly asthmatic and 19 healthy control subjects at similar levels of bronchoconstriction while subjects were supine. We also assessed the effects of deep inhalation and albuterol on supine lung mechanics. Measures of heterogeneity included lung attenuation, from which we derived a novel index of air-space size, and the frequency dependence of respiratory system resistance between 1 and 20 Hz. We found that asthmatic subjects had airways hyperresponsiveness to methacholine in the sitting position compared with controls, but both groups had similar falls in forced expiratory volume in 1 s after inhaling methacholine while supine. There were no baseline differences between the groups in the frequency dependence of resistance, or lung attenuation, before methacholine, and both groups responded similarly with an increase in air-space size (+9.2% vs. +3.4%), air-space size heterogeneity (+9.8% vs. +4.2%), and frequency dependence of resistance (+76% vs. +86%) after methacholine. Deep inhalation did not affect resistance in either group, but albuterol significantly reduced resistance in both groups. We conclude that both computerized tomography and the forced oscillation technique demonstrate increased heterogeneity of airway narrowing during induced bronchoconstriction while supine and that this heterogeneity is equivalent between subjects with mild asthma and healthy controls when bronchoconstricted to the same degree. Thus heterogeneity appears to be a fundamental feature of bronchoconstriction and is not unique to mild asthma.

Is Pulmonary Arterial Hypertension in Neurofibromatosis Type 1 Secondary to a Plexogenic Arteriopathy?

Neurofibromatosis type 1 (NF1) is a common disorder of dysregulated tissue growth secondary to mutations in the tumor suppressor gene NF1. Pulmonary arterial hypertension (PAH) in patients with NF1 is hypothesized to be secondary to an underlying vasculopathy. We describe the entity we term NF1-associated PAH (NF1-PAH) in four new patients and update the data on four previously published reports of patients with PAH and NF1. We performed genetic testing of the bone morphogenic protein receptor 2 (BMPR2) gene, which mutated in 70% of patients with familial PAH and approximately 25% of patients with idiopathic PAH. We report, for the first time, pathologic findings in the autopsy-obtained lung of one patient with NF1-PAH. Patients with NF1-PAH have a generally poor long-term prognosis. In four patients, we observed the mosaic pattern of lung attenuation on a CT scan of the chest, a radiographic finding that can be consistent with an underlying vasculopathy. No mutations or rearrangements in the BMPR2 gene were found. We observed complex plexiform lesions in the one available autopsy specimen. Similar lesions are a hallmark of plexogenic pulmonary arteriopathy and are associated with several severe types of PAH. (Plexiform lesions should not be confused with plexiform neurofibromas, which are distinctive tumors seen in NF1.) Our findings suggest that NF1 should be considered as being "associated with PAH as outlined in the Revised Clinical Classification of Pulmonary Hypertension. Understanding the mechanism of PAH in NF1 may inform the pathogenesis of PAH, NF1-PAH itself, and other NF1-associated vasculopathies. The pulmonary vasculature should now be included among the arterial beds affected by NF1 vasculopathy.

Detection and quantification of the parenchymal abnormalities in emphysema using pulmo-CT

We aimed to determine the degree and extent of parenchymal abnormalities on pulmo-CT in patients with emphysema. The study group consisted of 29 patients (18 male, 11 female; mean age 57.9 ± 13). The diagnosis was based on clinical symptoms, pulmonary function tests (PFT) values, and chest CT findings. All of the patients CT scans were obtained during suspended deep inspiration from the apices to the costophrenic angles. The mean lung attenuation (MLD) and parenchymal abnormalities related to emphysema were quantitatively calculated with tables, histograms and graphics at the whole lung. The lung density measurements revealed a mean density of −898.48 ± 51.37 HU in patients with emphysema and −825.1 ± 25.5 HU in control group. In addition, mean percentage of subthreshold attenuation values was found as 12.03 ± 15.75 and 1.07 ± 0.83 in patients with emphysema and control group, respectively. Compared with control group, the patients with emphysema had a significantly lower inspiratory MLD ( p < 0.05). Additionally, statistically significant correlations were seen between the MLD and percentage of subthreshold values ( r = 0.44, p < 0.05). In contrast, there was poor correlation between PFT measurements and the subthreshold values. In conclusion, pulmo-CT is a quick, simple method for quantitative confirmation of the presence of parenchymal abnormalities of lung as mosaic attenuation and should be used in combination with other radiological methods and PFT as it gives additional information to routine examinations in patients with emphysema.

Characterization of the Relation Between CT Technical Parameters and Accuracy of Quantification of Lung Attenuation on Quantitative Chest CT

The purpose of this study was to assess the compromise between CT technical parameters and the accuracy of CT quantification of lung attenuation. Materials that simulate water (0 H), healthy lung (-650 H), borderline emphysematous lung (-820 H), and severely emphysematous lung (-1,000 H) were placed at both the base and the apex of the lung of an anthropomorphic phantom and outside the phantom. Transaxial CT images through the samples were obtained while the effective tube current was varied from 440 to 10 mAs, kilovoltage from 140 to 80 kVp, and slice thickness from 0.625 to 10 mm. Mean +/- SD attenuation within the samples and the standard quantitative chest CT measurements, the percentage of pixels with attenuation less than -910 H and 15th percentile of attenuation, were computed. Outside the phantom, variations in CT parameters produced less than 2.0% error in all measurements. Within the anthropomorphic phantom at 30 mAs, error in measurements was much larger, ranging from zero to 200%. Below approximately 80 mAs, mean attenuation became increasingly biased. The effects were most pronounced at the apex of the lungs. Mean attenuation of the borderline emphysematous sample of apex decreased 55 H as the tube current was decreased from 300 to 30 mAs. Both the 15th percentile of attenuation and percentage of pixels with less than -910 H attenuation were more sensitive to variations in effective tube current than was mean attenuation. For example, the -820 H sample should have 0% of pixels less than -910 H, which was true at 400 mA. At 30 mA in the lung apex, however, the measurement was highly inaccurate, 51% of pixels being below this value. Decreased kilovoltage and slice thickness had analogous, but lesser, effects. The accuracy of quantitative chest CT is determined by the CT acquisition parameters. There can be significant decreases in accuracy at less than 80 mAs for thin slices in an anthropomorphic phantom, the most pronounced effects occurring in the lung apex.

Pulmonary Complications of Illicit Drug Use

The aim of this manuscript is to summarize an approach to the differential diagnosis of the pulmonary complications of illicit drug use based on the computed tomography findings. The various pulmonary complications of illicit drug use result in 5 main patterns of parenchymal abnormality: nodules, ground-glass opacities, consolidation, air trapping, and emphysema. Other thoracic manifestations of illicit drug use include pulmonary arterial hypertension, pneumomediastinum, bacterial endocarditis, discitis, and septic arthritis.

A Case of Lung Cancer showing Widespread Ground Glass

The patient was a man in his late seventies who complained of coughing. He was a former smoker. A thoracic computed tomography (CT) image revealed a large area of ground-glass opacity (GGO) in the right upper lobe that was a slight increase in lung attenuation without obscuring the underlying bronchial and vascular structures (Fig. 1). The maximum size of the area of GGO was 7 cm in diameter and there were also some areas of consolidation in it. The area of GGO in the upper lobe extended to the lower lobe via the incomplete fissure between the two lobes (Fig. 2). A transbronchial biopsy of the GGO area revealed adenocarcinoma. On the diagnosis of a lung cancer, a right upper lobectomy with superior segmentectomy of the lower lobe was performed. Microscopically, the GGO area corresponded to replacement growth of cancer cells lining along the alveolar walls, while the areas of consolidation corresponded to cancer cells invading the stroma with active fibroblasts. Surgical margin was negative and there was no lymph node metastasis. The patient is doing well without recurrence for 5 years.

Lung CT Densitometry in Systemic Sclerosis: Correlation With Lung Function, Exercise Testing, and Quality of Life

Background:To ascertain if analysis of lung density histograms in thin-section CT was more reproducible than visual assessment of lung changes in systemic sclerosis (SSc), and if such density histogram parameters as mean lung attenuation (MLA), skewness, and kurtosis could more closely reflect pulmonary function as well as exercise and quality of life impairment.Methods:The intraoperator and interoperator reproducibility of visual and densitometric lung CT analysis in 48 SSc patients examined with CT were evaluated by means of weighted κ statistics. Univariate and multivariate regression analyses were applied to evaluate the relationship of visual and densitometric CT measurements with functional parameters including functional residual capacity (FRC), FVC, FEV1, diffusion capacity of the lung for carbon monoxide (Dlco), 6-min walking testing (6MWT), and health-related quality of life questionnaire (QLQ) parameters.Results:The intraoperator and interoperator reproducibility of MLA (intraobserver weighted κ = 0.97; interobserver weighted κ = 0.96), skewness (intraobserver weighted κ = 0.89; interobserver weighted κ = 0.88), and kurtosis (intraobserver weighted κ = 0.89; interobserver weighted κ = 0.88) were higher than those of visual assessment (intraobserver weighted κ = 0.71; interobserver weighted κ = 0.69). In univariate analysis, only densitometric measurements were correlated with some exercise and QLQ parameters. In multivariate analysis, MLA (square regression coefficient corrected [R2c] = 0.70), skewness (R2c = 0.78), and kurtosis (R2c = 0.77) were predicted by FRC, FVC, Dlco, 6MWT, and QLQ parameters, while visual assessment was associated only with FRC and FVC (R2c = 0.40).Conclusions:In SSc, densitometric analysis is more reproducible than visual assessment of lung changes in thin-section CT and more closely correlated to pulmonary function testing, 6MWT, and QLQ. Density histogram parameters may be useful for cross-sectional and longitudinal studies of lung involvement in SSc.

Rho GTPase Rac1 is critical for neutrophil migration into the lung

AbstractNeutrophils are critical in the inflammatory process by moving rapidly to tissue sites of inflammation. Members of the small Rho GTPase family, Rac1, Rac2, CDC42, and RhoA, are central regulators of cell migration by cytoskeleton rearrangement. The role of Rac1 in neutrophil migration related to inflammatory processes has remained elusive and has yet to be determined in physiologic in vivo models. We previously demonstrated a role for Rac1 in tail retraction. Here, we present evidence that Rac1-mediated uropod formation may be due to crosstalk with a related Rho GTPase RhoA. To assess the physiologic relevance of these findings, we used adoptive transfer of Rac1flox/flox bone marrow cells which allows postengraftment in vivo deletion of Rac1 only in blood cells. We examined the specific role of Rac1 in neutrophil migration into the lung during the inflammatory process induced by formyl-methionyl-leucyl-phenylalanine exposure. The loss of Rac1 activity in neutrophils is associated with a significant decreased neutrophil recruitment into lung alveolar and attenuation of emphysematous lesions. Overall, this study suggests that Rac1 is a physiologic integrator of signals for neutrophil recruitment into lung tissue during an inflammatory response.

Air trapping in mild and moderate asthma: Effect of inhaled corticosteroids

Air trapping reflects small airway obstruction in asthma and can be assessed quantitatively by high-resolution computed tomography (HRCT). Hydrofluoroalkane-beclomethasone dipropionate (HFA-BDP) is deposited across all sizes of airways, including the small ones. However, its long-term effect on air trapping remains unknown in uncontrolled asthma. To compare the effect of inhaled corticosteroids of different particle size - HFA-BDP and fluticasone propionate (FP) - on lung attenuation in mild-to-moderate uncontrolled asthma. A randomized study was performed to analyze the effect of HFA-BDP (400 microg/d) or FP (500 microg/d) given over a period of 3 months to patients with uncontrolled mild-to-moderate asthma. HRCT was performed with spirometric gating, and lung attenuation was measured at residual volume and at pulmonary total capacity. The difference between inspiratory and expiratory attenuation was calculated as an air trapping index. Twenty-five out of 58 patients had abnormal air trapping and could be included in the study. Lung attenuation significantly diminished in the posterior zones of the lung after a 3-month treatment with HFA-BDP or FP, but the difference between the groups was not significant. Adjusted mean variations of the air trapping index from baseline to treatment completion were 34.3 (11.2, 57.3) and 27.3 (6.4, 48.2) for the HFA-BDP and FP groups, respectively. However, the reduction of air trapping area was more pronounced in the group treated with HFA-BDP. Inhaled corticosteroids decrease air trapping in uncontrolled asthma regardless of their particle size. In mild-to-moderate asthma, air trapping assessed by HRCT may be a new outcome related to the control of the disease.

Comparison of Standard- and Low-Radiation-Dose CT for Quantification of Emphysema

This study was performed to compare standard- and low-radiation-dose techniques in the CT quantification of emphysema. The study population consisted of 36 men and 20 women who were current or former heavy smokers and underwent standard-dose (effective tube current, 100-250 mAs) chest CT at our institution within 6 months of having undergone low-dose (effective tube current, 30-60 mAs) chest CT. All CT scans were reconstructed at 5-mm slice thickness with a smooth filter. CT-measured lung volume, mean and median lung attenuation, and percentage of lung volume with attenuation lower than multiple thresholds (emphysema index values) were compared by Pearson correlation, two-tailed and paired Student's t tests, and regression analysis. There were no significant differences in mean attenuation (-848 vs -846 H, p > 0.35) for the low dose and the standard dose or in median lung attenuation (-879 vs -878 H, p > 0.66). Low- and standard-dose emphysema indexes were correlated at all attenuation thresholds (r = 0.86-0.97). Mean emphysema indexes were higher on the low-dose scans, but the mean difference at all thresholds was less than 3%. The differences were significant (p < 0.05) only at the lower index thresholds, correlated with differences in lung volume (r < or = 0.86), and increased with greater differences in dose. Low-dose technique has minimal effect on CT quantification of emphysema.

Anti-endotoxin Hyperimmune Globulin Attenuates Portal Cytokinaemia, Phagocytic Cell Priming, and Acute Lung Injury after Lower Limb Ischaemia-reperfusion Injury

Acute limb ischaemia is a common and often lethal clinical event. Reperfusion of an ischaemic limb has been shown to induce a remote gut injury associated with transmigration of endotoxin into the portal and systemic circulation, which in turn has been implicated in the conversion of the sterile inflammatory response to a sepsis syndrome, after lower torso ischaemia-reperfusion injury. This study tests the hypothesis that an anti-endotoxin hyperimmune globulin attenuates ischaemia-reperfusion (I/R) associated sepsis syndrome. Prospective, randomised placebo controlled trial, animal experiment. Experimental porcine model, bilateral hind limb I/R injury, randomised to receive anti-endotoxin hyperimmune globulin or placebo. Bilateral hind limb I/R injury significantly increased intestinal mucosal acidosis, portal endotoxaemia, plasma cytokine (TNF-alpha, IL-6, IL-8) concentrations, circulating phagocytic cell priming and pulmonary leukosequestration, oedema, and capillary-alveolar protein leak. Conversely, pigs treated with anti-endotoxin hyperimmune globulin (IgG) 20mg/kg at onset of reperfusion had significantly reduced portal endotoxaemia, early circulating phagocytic cell priming, plasma cytokinaemia and attenuation of acute lung injury. Endotoxin translocation across a hyperpermeable gut barrier, phagocytic cell priming and cytokinaemia are key events of limb I/R injury induced systemic inflammation and acute lung injury. This study shows that an anti-endotoxin hyperimmune globulin attenuates portal endotoxaemia, which may reduce early phagocytic cell activation, cytokinaemia and ultimately acute lung injury.

Comparison of airway dimensions in different anatomic locations on chest CT in patients with COPD

It is not well known whether there is heterogeneity in the airway dimensions at different anatomic locations in individual patients with COPD. The first objective was to compare airway dimensions of the basal segment bronchus between COPD patients and healthy controls. The second and third objectives were to compare the airway dimensions in two anatomic locations, and to investigate the relationship between CT measurements and pulmonary function among COPD patients. Thirty males with COPD (aged 68.7 +/- 8.1 years) and 18 healthy males (aged 64.9 +/- 14.0 years) were enrolled in the study. COPD was diagnosed according to the criteria of the Global Initiative for Obstructive Lung Disease Workshop Report. Pulmonary function tests and CT scans were performed on all subjects. Airway dimensions and lung attenuation were automatically determined using methods that were validated with a phantom. Age, smoking index and height did not significantly differ between the COPD patients and healthy controls. The COPD patients had a significantly thicker airway wall than healthy controls. Among the COPD patients, there were no significant differences in the airway dimensions of bronchi in different segments; however, the airway and lung attenuation measurements of the lower lung field were more strongly correlated with FEV(1) than those of the upper lung field. Patients with COPD had no significant heterogeneity in airway dimensions at different anatomic locations. The airway and lung attenuation measurements of the lower lung field were more strongly correlated with airflow limitation than those of the upper lung field.

Clinical and radiological features of bronchiolitis obliterans in children

目的 探讨胸部X线片和薄层CT对儿童闭塞性毛细支气管炎(BO)的诊断价值.方法回顾性分析12例经临床诊断证实的BO患儿的资料,其中男9例,女3例,年龄5个月～11岁,所有患儿症状均持续6周以上.12例均行胸部前后位X线片、肺部薄层CT、纤维支气管镜、痰液、支气管肺泡灌洗液和肺功能检查,1例行肺灌注扫描.结果12例均有典型临床特征和肺功能不可逆性小气道阻塞;1例肺灌注扫描示右下肺下段偏外侧放射性缺损低血流灌注表现;9例纤维支气管镜检为支气管内膜炎;4例活检病理提示慢性炎症.胸部X线片表现为:肺透光度增高8例;肺纹理增多,增粗6例;肺实变或不张6例;单侧或局限性透明肺4例.薄层CT表现为:马赛克征象,实质密度减低11例,血管细少10例;支气管扩张7例;支气管壁增厚9例;单侧或限局性透明肺4例.实质病变6例;结节征3例;支气管黏液栓5例.结论儿童BO的薄层CT表现比胸部X线片更具有特征性,诊断儿童BO可以基于临床表现、薄层CT和肺功能检查。

Prospective prevalence of pathologic gambling and medication association in Parkinson disease

The authors prospectively screened 297 patients with Parkinson disease (PD), who attended a tertiary clinic, using a modified South Oaks Gambling Scale. Lifetime prevalence of pathologic gambling (PG) was 3.4% and on any dopamine agonist was 7.2%. PG was associated with earlier PD onset and with dopamine agonists but not with agonist subtype or doses. We found no association with a potent D3 receptor agonist.