Pulmonary lymphangioleiomyomatosis: correlation of ventilation-perfusion scintigraphy, chest radiography, and CT with pulmonary function tests

PURPOSE: To determine the findings on ventilation-perfusion (V-P) scintigrams, computed tomographic (CT) scans, and chest radiographs and correlate them with pulmonary function test results in patients with lymphangioleiomyomatosis. MATERIALS AND METHODS: V-P scintigraphy, chest radiography, conventional and thin-section CT, and pulmonary function tests were performed in 39 patients. The images were graded on a scale of 0 (normal) to 3 (severely abnormal). RESULTS: Imaging abnormalities were found on 92% of ventilation scintigrams, 92% of perfusion scintigrams, 79% of chest radiographs, 100% of CT scans, and 100% of thin-section CT scans. On ventilation scintigrams, 28 (72%) patients demonstrated a speckling pattern. On CT scans, all patients had pulmonary cysts. Univariate analysis showed that extent of disease on chest radiographs and CT scans, cyst size, V-P abnormalities, and degree of speckling were inversely correlated with forced expiratory volume in one second (FEV(1)), diffusing capacity of lung for carbon monoxide, and the ratio of FEV(1) to forced vital capacity (FVC) (P <.01) but not with FVC and total lung capacity. Larger cyst size correlated with extent of disease at CT, but not significantly (P =.056). CONCLUSION: Scintigraphic and radiologic abnormalities are seen in a majority of patients with lymphangioleiomyomatosis. On ventilation scintigrams, a frequently seen speckling pattern may be related to accumulation of radionuclide in pulmonary cysts-a hallmark of the disease at CT. Findings with each imaging modality correlate with certain pulmonary functions.     

Can routine chest radiography be used to diagnose mild COPD? A nested case-control study

ObjectivesTo determine whether mild stage chronic obstructive pulmonary disease (COPD) can be detected on chest radiography without substantial overdiagnosis.MethodsA retrospective nested case-control study (case:control, 1:1) was performed in 783 patients scheduled for cardiothoracic surgery who underwent both spirometry and a chest radiograph preoperative. Diagnostic accuracy of chest radiography for diagnosing mild COPD was investigated using objective measurements and overall appearance specific for COPD on chest radiography. Inter-observer variability was investigated and variables with a kappa >0.40 as well as baseline characteristics were used to make a diagnostic model which was aimed at achieving a high positive predictive value (PPV).ResultsTwenty percent (155/783) had COPD. The PPV of overall appearance specific for COPD alone was low (37–55%). Factors in the diagnostic model were age, type of surgery, gender, distance of the right diaphragm apex to the first rib, retrosternal space, sternodiaphragmatic angle, maximum height right diaphragm (lateral view) and subjective impression of COPD (using both views). The model resulted in a PPV of 100%, negative predictive value (NPV) of 82%, sensitivity of 10% and specificity of 100% with an area under the curve of 0.811.ConclusionsDetection of mild COPD without substantial overdiagnosis was not feasible on chest radiographs in our cohort.     

The prognostic value of perfusion lung scintigraphy in patients who underwent single-lung transplantation for emphysema and pulmonary fibrosis.

The objective of this study was to evaluate the role of quantitative perfusion lung scintigraphy (QPLS) in predicting the development of chronic rejection in patients who underwent single-lung transplantation. METHODS: Eighteen patients (15 men, 3 women; age range, 41-60 y; mean age, 54.6+/-6.0 y) who underwent single-lung transplantation for emphysema (n = 14) or pulmonary fibrosis (n = 4) were studied. Patients were evaluated using QPLS and pulmonary function tests before surgery and at 1-3 mo and 1-3 y after transplantation. Relative perfusion of the transplanted lung was calculated from standard perfusion lung scintigrams. Values for forced expiratory volume in the first second (FEV1) were obtained from lung function tests at the same time points. The maximal and minimal relative perfusion and FEV1 values in the early (1-3 mo) and late (1-3 y) follow-up periods were identified for each patient. Receiver operating curve (ROC) analysis was performed on all parameters. RESULTS: In total, 82 lung scans were performed (mean, 4.8+/-1.55 per patient) and 484 FEV1 test determinations were obtained (mean, 30.0+/-15.6 per patient) during a follow-up period ranging from 8 to 84 mo (mean, 39.6+/-19.3 mo). In 7 of the 18 patients, chronic rejection developed, whereas 11 patients had a favorable outcome. No significant difference was found in the number of complications (acute rejection and infection episodes) between patients with a favorable outcome and patients with chronic rejection, up to 1 y after transplantation. At 1-3 mo, minimal relative perfusion values were 67.1%+/-12.2% in the favorable outcome group and 50.8%+/-9.6% in the chronic rejection group (P = 0.02). Before surgery and at 1-3 y, minimal relative perfusion was not significantly different between the 2 groups. The difference in maximal relative perfusion at 1-3 y was marginally significant, with 76.5%+/-8.9% in the favorable group and 64.3%+/-15.0% in the chronic rejection group (P = 0.051). FEV1 values were not significantly different preoperatively and 1-3 mo after surgery between the chronic rejection and the favorable outcome groups. Late in the follow-up period (1-3 y), FEV1 values in the chronic rejection and favorable outcome groups were 35.6%+/-7.9% and 56.9%+/-13.6%, respectively (P = 0.002). ROC analysis of minimal relative perfusion at 1-3 mo identified a threshold of 57% under which the sensitivity and specificity for chronic rejection were 83% and 88%, respectively. Minimal FEV1 for the same period identified a threshold of 48% under which the sensitivity and the specificity were 80% and 67%, respectively. CONCLUSION: QPLS early after transplantation in our patients predicted the development of chronic rejection in patients with single-lung transplantation for emphysema and pulmonary fibrosis, whereas surgical complications, acute rejection, infection episodes, and lung function tests did not predict the outcome. This early prediction could not be obtained from lung function tests performed at the same time.     

Differentiating lung abscess and empyema: radiography and computed tomography

Conventional chest radiographs and computed tomographic (CT) scans of 70 inflammatory thoracic lesions in 63 patients were reviewed and scored for diagnostic features. Pathologic confirmation of the final diagnosis was available in 42% (5/12) of lung abscesses and 31% (18/58) of empyemas. CT alone was sufficient to correctly diagnose 100% (70/70) of cases. Diagnostic information not available from conventional chest radiographs was obtained in 47% (33/70) of cases; in an additional 34% of patients, CT more accurately defined the extent of disease. The most reliable CT features for the differential diagnosis of lung abscess and empyema were wall characteristics, pleural separation, and lung compression. Conventional radiographic features such as size, shape, and the angle of the lesion with the chest wall were less helpful, though also best assessed by CT.     

Functional impairment in emphysema: contribution of airway abnormalities and distribution of parenchymal disease

OBJECTIVE: The aim of this study was to identify ancillary morphologic features on high-resolution CT that modify airflow obstruction and gas transfer levels in individuals with emphysema. MATERIALS AND METHODS: The extent of emphysema on high-resolution CT was quantified by density masking in 101 patients. CT scans were evaluated for airway abnormalities (bronchial wall thickness, extent of bronchiectasis, bronchial dilatation, and evidence of small airways disease) and disease heterogeneity (uniformity, core-rind distribution, craniocaudal distribution, and lung texture). Stepwise regression analysis was used to determine CT features that influenced forced expiratory volume in 1 sec (FEV1) and the single-breath diffusing capacity for carbon monoxide (Dlco) for a given extent of emphysema. RESULTS: The extent of emphysema using automated estimation was 28.4% +/- 12.3% (mean +/- SD). On univariate analysis the extent of emphysema correlated strongly with FEV1 (R = -0.63, p < 0.0005) and Dlco (R = -0.63, p < 0.0005) levels. Stepwise regression analysis revealed that bronchial wall thickness and the extent of emphysema were the strongest independent determinants of FEV1 (model R2 = 0.49; p = 0.002 and < 0.001, respectively); the extent of bronchiectasis and degree of bronchial dilation did not separately influence FEV1 levels. The only morphologic features linked to Dlco levels on multivariate analysis were increasingly extensive emphysema and a higher proportion of emphysema in the core region (model R2 = 0.45; p < 0.001 and 0.002, respectively). CONCLUSION: The important additional CT abnormalities in individuals with emphysema that influence FEV1 and Dlco levels irrespective of disease extent are bronchial wall thickness and core-rind heterogeneity, respectively. These observations have implications for the accurate functional assessment of patients considered for lung volume reduction surgery.     

Postoperative chest radiographic changes after on- and off-pump coronary surgery

AIM: A variety of chest radiograph abnormalities are recognized after coronary artery bypass grafting (CABG). This study analyzes the appearance of preoperative and postoperative chest radiographs in two groups of patients undergoing myocardial revascularization with or without the use of cardiopulmonary bypass (CPB). METHODS: Chest radiographs (preoperative and at 1 day, 6 days and 6 to 8 weeks post operatively) were analyzed according to a detailed protocol in cases of conventional CABG on CPB (n=60) or off-pump coronary artery bypass (OPCAB) (n=60) surgery. On each film 17 different major potential postoperative abnormalities were analyzed. RESULTS: Clinical findings were similar in the two groups. Patients undergoing OPCAB surgery had decreased blood loss, decreased red cell and platelet transfusion, significantly lower intubation time and required less postoperative inotropic support compared with patients undergoing CPB. The CPB group had a significantly higher incidence of left band atelectasis than the OPCAB group (37.6% vs 17.5%, p=0.01) at 6 days postoperatively. There was no other statistically significant difference in any of the 16 remaining major chest radiograph findings between the two groups. CONCLUSION: Although OPCAB surgery is associated with improved clinical outcome compared with conventional CABG surgery, the analysis of postoperative chest radiographs demonstrated only a minor benefit as shown by a reduced degree of left band atelectasis in the OPCAB group.     

Prediction of postoperative lung function in patients with lung cancer: comparison of quantitative CT with perfusion scintigraphy

OBJECTIVE: Prediction of postoperative lung function is important in preoperative evaluation of patients with lung cancer. Perfusion scintigraphy is the current method to assess the fractional contribution of lung function of the remaining lung. We developed a quantitative CT method and compared it with perfusion scintigraphy for predictions of postoperative forced expiratory volume in 1 sec (FEV1) in patients with lung cancer. SUBJECTS AND METHODS: Forty-four patients with lung cancer undergoing lung resection with preoperative CT and perfusion scintigraphy were enrolled. Quantitative CT used a dual threshold (-500 and -910 H) on standard preoperative CT to semiautomatically extract lung volume without emphysema or tumor and atelectasis, which we defined as "functional lung volume." Prediction was calculated from preoperative FEV1 multiplied by the fractional contribution of functional lung volume of the remaining lung by quantitative CT. Perfusion scintigraphy was the standard method. Predictions were correlated with postoperatively measured FEV1. RESULTS: Both quantitative CT and perfusion scintigraphy predicted postoperative FEV1 well in patients who underwent pneumonectomy (n = 28, r = 0.88 vs r = 0.86) and in lobectomy (n = 16, r = 0.90 vs r = 0.80) (both, p < 0.001). There was good agreement between the two methods by the Bland-Altman method. In the four patients with low measured postoperative FEV1 (<40% predicted normal), quantitative CT had true-positive prediction in four and perfusion scintigraphy, in only two. CONCLUSION: Given its simplicity, we proposed that quantitative CT be widely used in predicting postoperative FEV1.     

手术治疗脊髓型颈椎病预后因素分析

目的确定磁共振(MRI)成像和脊髓型颈椎病(CSM)患者的临床、人口统计学指标是否与基线功能评分独立相关,探讨其是否能够预测术后功能结果。方法对2010年7月至2011年5月解放军252医院收治的61例CSM患者进行前瞻性分析。采用改良日本骨科协会(mJOA)评分量化患者入院时及术后12个月的病残程度。对患者年龄、性别、症状持续时间、脊髓病变的严重程度、脊柱轴线、手术技术、压迫节段、前后径、最大脊髓压迫部位的横向面积、MRI成像信号强度的变化进行评估。研究收集的数据包括:患者人口统计学数据;术前基线mJOA评分;术后12个月mJOA评分;MRI影像学数据,如脊柱轴线,前后位直径(AP),最大压迫部位的横截面积(TA),脊髓信号强度(SI),压迫节段。数据分析采用Spearman秩相关检验,方差分析采用Mann-Whitney U检验和多元逐步回归。结果更高基线mJOA评分水平与低龄(年龄≤65岁)、症状持续时间较短,更大的横截面积相关(P<0.05)。更好的恢复率与低龄和高基线mJOA评分相关(P<0.05)。mJOA评分变化较高的与高基线mJOA水平相关(P<0.05)。使用多变量分析显示,脊髓型颈椎病术后的功能预后最佳预测因子是基线mJOA评分和患者年龄。结论年龄和基线mJOA评分是接受手术治疗的CSM患者功能预后的显著预测因子。脊髓受压程度和核磁共振T1/T2加权图像上信号强度的变化并不是独立预测因子,但发现其与患者当时的功能状态、年龄等相关。症状的持续时间与术前功能状态密切相关,但并没有影响术后的结果。     

Lung volume reduction surgery for emphysema: correlation of CT and V/Q imaging with physiologic mechanisms of improvement in lung function

PURPOSE: To compare the relationship between computer-derived and visually assessed ventilation-perfusion (V/Q) scintigraphy and computed tomographic (CT) scores in evaluating disease severity and distribution in identifying optimal candidates for lung volume reduction surgery (LVRS) and to correlate these radiologic indices with physiologic measures of outcome. MATERIALS AND METHODS: In 39 patients, preoperative V/Q and CT scans were visually scored by two radiologists for disease severity and distribution. Results were compared with computer-derived scores for the same cohort. These indices were correlated with clinical improvement measured with forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and ratio of FEV(1) to FVC. RESULTS: The disease distribution scores measured with the different methods correlated closely: computer-based and visually assessed CT scores (r = 0.89, P <.001), computer-based and visually assessed V/Q scores (r = 0.83, P <.001), visually assessed CT and V/Q scores (r = -0.50, P <.001), and computer-derived CT and V/Q scores (r = -0.57, P =.015). Similarly, a statistically significant correlation was noted between each of the radiologic methods and clinical outcome measurements (P <.001). CONCLUSION: CT and V/Q preoperative assessment, with either visual scoring or computer-based algorithms, are nearly equivalent in their utility in predicting improvement in FEV(1) measures.     

Diagnostic accuracy of thin-section CT and chest radiography of pediatric interstitial lung disease

OBJECTIVE: We assessed the accuracy of thin-section CT and chest radiography to diagnose pediatric interstitial lung disease. MATERIALS AND METHODS: We identified 20 infants, boys, and girls (age range, 1 month to 14 years) with histopathologic confirmation of interstitial lung disease. Six boys and girls without interstitial lung disease were also included. Two observers independently assessed chest radiograph and CT images. The observers stated the most likely diagnosis and a differential diagnosis. We evaluated individual CT features and their distribution. RESULTS: Observers' diagnoses on CT images were correct (first choice or differential) in 66% of observations versus 45% on chest radiographs (p < 0.025). Correct diagnoses were made on first choice in 61% of CT observations versus 34% on chest radiographs (p < 0.005). Observers were confident (versus uncertain) in 42% of the CT observations versus 18% on chest radiographs; of the confident diagnoses made on CT, 91% were correct. CT interpretations were most accurate in the diagnosis of pulmonary alveolar proteinosis, congenital lymphangiectasia, and idiopathic pulmonary hemosiderosis. All healthy patients examined with CT were correctly identified as such. We noted a distinctive CT pattern in three patients with nonspecific interstitial pneumonitis and one patient with desquamative interstitial pneumonitis; the CT pattern consisted of upper zone predominant honeycombing on a background of ground-glass attenuation. CONCLUSION: A higher proportion of pediatric interstitial lung diseases can be diagnosed on thin-section CT than on chest radiographs. In our study, confident and correct diagnoses were made more frequently with CT than with chest radiographs.     

Evaluation of diagnostic accuracy of CRT monitor display for personal computer in the detection of small lung nodules: with particular emphasis on comparison between JPEG and wavelet compression

PURPOSE: To compare observer performance on cathode-ray-tube(CRT) monitors for personal computers with that on conventional radiographs in the detection of small lung nodules. MATERIALS AND METHODS: Fifty-eight normal chest radiographs and 58 chest radiographs with a small lung nodule were selected. Ten radiologists examined the original conventional films on a viewbox and digitized (8 bit) uncompressed and compressed images of the same patient on a color CRT monitor with a matrix of 1,600 x 1,200, and rated the presence of lung nodules with a five-level scale of confidence. The methods of compression used in this study were the JPEG and wavelet methods, with compression ratios of 6:1 and 15:1. Results were analyzed by receiver operating characteristic methods. RESULTS: There was no significant difference between film and digitized uncompressed and compressed images obtained by the JPEG and wavelet methods with a compression ratio of 6:1. No statistically significant difference was detected between film and digitized image with wavelet compression at 15:1. However, detection was less accurate on digitized images with JPEG compression at 15:1. CONCLUSION: Digitized (8 bit) uncompressed and compressed images with a compression ratio of 6:1 are acceptable for the detection of small lung nodules. Digitized compressed images at a compression ratio of 15:1 are also acceptable when the wavelet method is used.     

Fibrosing alveolitis: chest radiography and CT as predictors of clinical and functional impairment at follow-up in 26 patients.

Findings on the original and follow-up chest radiographs and computed tomographic (CT) scans were correlated with clinical and functional parameters in 26 patients with fibrosing alveolitis. Assessment of chest radiographs included determination of a standard profusion score and an average profusion score. The CT assessment included pattern, extent, and distribution of disease. The standard profusion score showed no significant correlation with clinical or functional parameters (P greater than .05). However, the average profusion score of the six lung zones correlated with severity of dyspnea and with static lung volumes (P less than .01). Extent of irregular linear opacities on CT scans correlated with severity of dyspnea and impairment in gas transfer (carbon monoxide-diffusing capacity) (P less than .01). The profusion of ground-glass opacities on the radiograph showed no significant correlations (P greater than .05). The profusion and extent of ground-glass opacities on CT scans correlated with severity of dyspnea, impairment in gas transfer, and reduction in static lung volumes (P less than .01). Ground-glass opacities on CT scans preceded and predicted the development of irregular linear opacities on follow-up CT scans and correlated with an increase in the average profusion score of the chest radiograph (P less than .01).     

Type B Niemann-Pick disease: findings at chest radiography, thin-section CT, and pulmonary function testing

PURPOSE: To evaluate findings at radiography, computed tomography (CT), and pulmonary function testing in patients with type B Niemann-Pick disease. MATERIALS AND METHODS: The study was approved by the institutional review board or ethics committee at each study site and was compliant with HIPAA at the U.S. site. Written informed consent was obtained from each patient or guardian and minor assent was obtained from all children before any study-related procedures. Pulmonary involvement in 53 patients (27 male and 26 female patients; age range, 7-65 years; mean age, 23.3 years) with type B Niemann-Pick disease was evaluated with imaging and pulmonary function tests. All patients underwent chest radiography and thin-section CT, and images were independently interpreted by one of two radiologists. Spirometry (forced vital capacity [FVC] and forced expiratory volume in 1 second [FEV1]) was performed and diffusing capacity of lung for carbon monoxide (Dlco) was evaluated in all patients who could comply. A score for the degree of interstitial lung disease was derived at both radiography and CT, and the CT scores were then compared with results of pulmonary function testing and patient age by means of linear regression. CT scores were compared between the upper and lower lung zones by using the Wilcoxon signed rank test. RESULTS: Chest radiography and CT, respectively, revealed interstitial lung disease in 47 (90%) and 51 (98%) of the 52 patients who completed both imaging examinations. There was a basilar predominance of interstitial lung disease at CT. Six patients had pulmonary nodules, one of which was calcified at chest radiography. There were no statistically significant correlations between interstitial lung disease score at CT and age or percentage predicted FVC, FEV1, or Dlco values. CONCLUSION: Although pulmonary function test indexes may be abnormal, imaging findings do not necessarily correlate with pulmonary function in patients with type B Niemann-Pick disease.     

Serial HRCT lung changes after 3-field radiation treatment of breast cancer

AIMS: To document serial high resolution computed tomography (HRCT) features of lung injury after 3-field radiotherapy for breast cancer. MATERIALS AND METHODS: Thirty women who received opposing tangential chest wall and supraclavicular field (SCF) irradiation after breast surgery were recruited. Thoracic HRCT was performed before and at 1, 3, 6 and 12 months after radiotherapy (RT). Lung injury at 3 months was quantified by applying a scoring system to each HRCT section. Findings were correlated with spirometric lung function tests. RESULTS: There was HRCT evidence of lung injury in 27 (90%) women at 1 month and in all 30 patients at 3 months. Spirometric lung function declined post-RT (P < 0.05), correlating with an increased SCF acute lung injury score at 3 months [r = -0.54 and -0.46, P = 0.01 and 0.03 for forced expiratory volume in 1st (FEV(1)) and forced vital capacity (FVC), respectively]. Lung injury on HRCT progressed from ground glass opacification at 1 month to nodular consolidation (3 months), increasing linear densities (6 months), and finally to residual subpleural linear and dense opacities (12 months). CONCLUSION: There is a high incidence of lung injury associated with 3-field radiotherapy for breast cancer, with concurrent SCF irradiation increasing the risk of lung damage and functional impairment. A characteristic sequence of HRCT changes is seen in most patients receiving this type of radiotherapy.Ooi, G. C. (2000). Clinical Radiology55, 817-824.     

Postbiopsy pneumothorax: estimating the risk by chest radiography and pulmonary function tests

Pulmonary function tests and chest radiographs of 160 patients who had had percutaneous needle biopsy of lung lesions were reviewed to determine the value of these examinations in estimating the risk of postbiopsy pneumothorax. Chest radiographs were evaluated subjectively for changes of obstructive and restrictive airway disease and for size and depth of lesion. Pulmonary function tests, consisting of simple spirometry (forced vital capacity, percentage of predicted forced vital capacity, forced expiratory volume in 1 sec, percentage of predicted forced expiratory volume in 1 sec, and [forced expiratory in 1 sec/forced vital capacity] X 100), and the pulmonologist's interpretation were evaluated. Pneumothorax developed in 46% (31/67) of patients who had obstructive airway disease according to the results of pulmonary function tests and in 42% (34/81) of those who had obstructive airway disease according to changes on chest radiographs, compared with 19% (10/53) and 25% (17/67) of those who had normal pulmonary function tests and chest radiographs, respectively. Pneumothorax developed in 46% (23/50) of patients who had findings of obstructive airway disease on both pulmonary function tests and on chest radiographs, compared with 7% (2/28) of patients who were classified as normal by both criteria. None of the patients who had normal pulmonary function tests required placement of a chest tube, whereas 19% (13/67) of those who had obstructive airway disease required chest tubes. Decreasing size of lesion and increasing depth of lesion were associated with a significant increase in the risk of pneumothorax. We conclude that the results of chest radiographs and pulmonary function tests are useful parameters for estimating the risk of postbiopsy pneumothorax.     

A chest radiograph scoring system in adult cystic fibrosis: correlation with pulmonary function

The Birmingham scoring system for chest radiographs was assessed in 40 adult cystic fibrosis patients, with particular reference to correlation with pulmonary function values. Forty 'initial' and forty 'follow-up' chest radiographs were scored. The mean initial age of the group was 17.5 +/- 5.0 years, and the mean age at follow-up was 23.3 +/- 5.3 years. The cross-sectional radiographic score correlated significantly with the values of three commonly measured, pulmonary function parameters (r = 0.65, 0.67, 0.58, P less than 0.0001). There was a significant correlation (r = 0.64, P less than 0.0001), between the change in radiographic score, and the change in percent predicted forced vital capacity (FVC%). There was a less significant correlation (r = 0.45, P less than 0.006) between the change in radiographic score and the change in per cent predicted forced expiratory volume in one second (FEV1%). We conclude that the Birmingham radiographic scoring system is suitable for quantitative radiological evaluation in adult cystic fibrosis.     

Quantitative lung perfusion scan as a predictor of aerosol distribution heterogeneity and disease severity in children with cystic fibrosis

BACKGROUND: The assessment of lung ventilation by radionuclide imaging has proved useful for the optimization of aerosol therapy in children with cystic fibrosis. Further analysis of lung perfusion may provide additional information. METHODS: Quantitative analysis of regional lung aerosol distribution (Tc phytates) and perfusion (Tc macroaggregates) homogeneity was performed in 18 children with cystic fibrosis, using the third and fourth spatial moments (skew and Kurtosis) of count distribution. Patients were chosen from a prospective study whose goal was to compare the efficacy of two nebulization methods of a radiolabelled aerosol: one session involved a nebulizer activated by patient inspiratory flow (control session), whereas the other involved a nebulizer powered by a pressure support device (PS session). RESULTS: Quantitative regional distribution of perfusion was similar to aerosol distribution, although skew and Kurtosis were lower, indicating better homogeneity. Perfusion skew was inversely correlated with pulmonary volumes and Shwachman score, even more significantly than ventilation skew. Using receiver operating characteristic curve analysis, a perfusion skew threshold of 0.67 was predictive of disease severity (FEV1 > or =60% or FEV1 <60%) with 86% sensitivity and 91% specificity. Furthermore, same skew threshold allowed the identification of patients who were 'PS responders' (greater amount of radioactivity deposited after the PS session) or 'PS non-responders' with 80% sensitivity and 77% specificity. CONCLUSION: Quantification of regional lung perfusion is easy to perform and heterogeneity of the distribution is closely correlated to disease severity. Moreover, perfusion skew can identify patients who are likely to benefit from pressure support (to optimize aerosol therapy) and may be helpful for orienting potential non-responders towards alternative therapies.     

Asbestos-related pleural disease and asbestosis: a comparison of CT and chest radiography

High-resolution CT (HRCT) has the ability to demonstrate both asbestos-related pleural disease and parenchymal abnormalities consistent with asbestosis. The role of CT in the diagnosis of asbestosis can be defined by comparing it with radiography. We evaluated 60 men who had a history of occupational exposure to asbestos and whose outside chest radiographs were considered abnormal. Chest radiographs (inside films) and HRCT were performed in all patients at our institution and were interpreted independently by experienced radiologists. Outside film results were compiled from the submitted reports. The final conclusion regarding the interpretation of the radiologic examinations was determined by consensus when disagreements existed. Positive predictive values (the likelihood that a positive report is correct) for pleural disease were: outside films 56%, inside films 79%, HRCT 100%. The positive predictive values for parenchymal disease were: outside films 51%, inside films 83%, HRCT 100%. The addition of HRCT to chest radiography is most useful in eliminating false-positive diagnoses of asbestos-related pleural disease caused by subpleural fat and false-positive diagnoses of parenchymal asbestosis in patients with extensive plaques or emphysema obscuring lung detail. The interpretation of chest radiographs in patients exposed to asbestos is often extremely difficult and subjective, and we recommend that positive findings (except calcified plaques) be confirmed with HRCT.     

CsI-detector-based dual-exposure dual energy in chest radiography for lung nodule detection: results of an international multicenter trial

To assess both sensitivity and specificity of digital chest radiography alone and in conjunction with dual-exposure dual-energy chest radiography for the detection and classification of pulmonary nodules. One hundred patients with a total of 149 lung nodules (3-45 mm; median, 11 mm) confirmed by CT were included in this study. Dual-exposure dual-energy chest radiographies of each patient were obtained using a CsI detector system. Experienced board-certified chest radiologists from four different medical centers in Europe reviewed standard chest radiographs alone and in conjunction with dual-energy images blinded and in random order. The reviewers rated the probability of presence, calcification and malignancy of all lung nodules on a five-point rating scale. Lesions detected were identified by applying a specific coordinate system to enable precise verification by the study leader. A receiver-operating characteristic (ROC) analysis was performed. In addition to the 149 true-positive CT proven lesions, 236 false-positive lung nodules were described in digital chest radiographies in conjunction with dual-energy chest radiographies. The cumulative sensitivity of chest radiography in conjunction with dual energy was 43%, specificity was 55%. For digital radiography alone, sensitivity was 35% and specifity was 83%. For the dual energy system, positive predictive value was 58%, and negative predictive value was 66% compared to the digital radiography with a positive predictive value of 59% and a negative predictive value of 65%. Areas under the curve in a ROC analysis resulted in 0.631 (95% confidence interval =0.61 to 0.65) for radiography with dual energy and 0.602 (95% confidence interval =0.58 to 0.63) for digital radiography alone. This difference was not statistically significant. For the detection of lesion calcification or the determination of malignancy, ROC analysis also failed to show significant differences. CsI-based flat-panel dual-exposure dual-energy imaging added to standard chest radiography did not show statistically significant improvement for the detection of pulmonary nodules, nor the identification of calcifications, nor the determination of malignancy.     

Longitudinal follow-up evaluation of pulmonary emphysema using high-resolution Computed Tomography (HRCT) study and pulmonary function tests]

PURPOSE: To evaluate the usefulness of HRCT in the identification of longitudinal progression of emphysema and to establish the sensitivity of HRCT compared with functional tests. MATERIAL AND METHODS: 15 ex-smokers with chronic obstructive lung disease were studied, using two consecutive HRCT examinations (t1 and t2); emphysema was evaluated by HRCT visual score and, at the same time, pulmonary function tests. RESULTS: As a whole, the extension of emphysema with HRCT presented a good correlation with Tiffeneau index (IT). At t1 a significant correlation between HRCT and IT was almost reached; it was achieved between HRCT and PaCO2, FEV1 and IT. At t2, there was a significant correlation between HRCT and IT, FEV1 and IT, FEV1 and PaO2, FEV1 and PaCO2, IT and PaO2. In the interval between t1 and t2 there was a significant worsening of HRCT visual score and IT, with no modification of FEV1, PaO2 and PaCO2. The change in HRCT visual score had a significant correlation with FEV1. DISCUSSION AND CONCLUSIONS: HRCT is able not only to identify and quantify anatomic emphysema, but also to evaluate progression of the disease. In the middle-short term anatomic emphysema worsens significantly and visual score HRCT is more sensitive than functional tests for longitudinal evaluation because emphysematous destruction is faster than decline in function. Furthermore emphysematous destruction in smokers progresses even after smoking cessation. The usefulness of combining HRCT with functional tests in the follow-up remains to be established. Longitudinal examination by HRCT could allow us to identify the smokers that tend to develop earlier and more seriously the symptoms of chronic obstructive lung disease.