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Objective:To explore the predictive value of low-dose biphasic (inspiratory and expiratory) CT air trapping sign and semi-quantitative score in predicting abnormal blood gas parameters and progression to severe disease in COVID-19 patients.Methods:Patients with non-severe COVID-19 who were diagnosed by nucleic acid testing and hospitalized in designated hospitals in Wuxi City from January 23 to February 29, 2020 were prospectively and consecutively recruited. All patients received low-dose biphasic CT examination on admission and repeated CT examination at regular intervals during the course. On the inspiratory phase admission of the bipolar CT, the scope of the lesion was evaluated by semi-quantitative score, and the air trapping sign on bipolar CT was assessed. The differences of semi-quantitative score, the presence of the air trapping sign and other clinical factors were compared between the patients with abnormal and the normal blood gas index, as well as between the cases progressed to severe disease and cases without disease progression using the independent sample t-test or χ 2 test. The area under the curve (AUC) of receiver operating characteristic (ROC) and the comprehensive discriminant improvement index (IDI) were used to evaluate the predictive effectiveness of the semi-quantitative scores, air trapping sign, and combination of two factors in differentiating cases with abnormal and normal blood gas indexes, as well as in differentiating cases with and without disease progression to severe COVID-19 cases. Results:In total 51 non-severe COVID-19 cases were included, with 16 cases showed air trapping sign during the first biphasic CT examination on admission. During the course of the disease, there were 13 patients with abnormal blood gas index, and 9 cases displaying air trapping sign (9/13). All 7 cases with progression to severe cases showed air trapping sign (7/7). Patients with advanced age, air trapping sign and higher semi-quantitative score were found more likely to have abnormal blood gas index ( t=3.10, χ 2=9.38, t=3.34, P<0.05); patients with advanced age, underlying diseases, air trapping sign and higher semi-quantitative score were more likely to develop into severe disease ( t=2.68, χ 2=6.65, χ 2=4.25, t=4.33, P<0.05). The AUC of semi-quantitative score, air trapping sign and combination of two factors in distinguishing abnormal blood gas index from normal blood gas index was 0.803, 0.754 and 0.794 respectively. The AUC of semi-quantitative score, air trapping sign and combination of two factors in distinguishing cases with progression to severe cases from non-progression was 0.881, 0.898 and 0.932, respectively. Air trapping sign combined with semi-quantitative score significantly improved the prediction effectiveness of disease progression, compared with semi-quantitative score or air trapping sign (IDI=0.271, 0.117). Conclusion:Air trapping sign and semi-quantitative score might be used as effective indicators to predict the progression of COVID-19 cases, and the combination of these two factors might be more helpful to predict the disease progression.
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Objective To establish and validate a voxel-based method for the quantitative detection of air trapping (AT),and to explore its diagnostic value by preliminarily apply this method in chronic obstructive pulmonary disease (COPD) patients.Methods From March 2015 to February 2016,fifty healthy young volunteers and eighteen COPD patients who underwent both end-inspiratory and end-expiratory CT were included from the Digital Lung Multi-center Study.The quantitative parameters of AT and emphysema were measured by both the voxel-based quantitative method and the conventional threshold method,respectively.All subjects underwent pulmonary function examination within 3 days after CT examination.For healthy volunteers,paired sample rank-sum test was used to compare the difference of quantitative parameters between voxel-based method and threshold method,Spearman rank correlation analysis was used to investigate the correlation between quantitative parameters of the two methods and pulmonary function.For COPD patients,the distribution and extent of AT and emphysema in patients with similar degree of pulmonary function (PFT) injury were observed.Results There were varying degrees of AT in the asymptomatic youth,with a median value of 5.70％ for the voxel-based method and with a median value of 7.96％ for the conventional threshold method,there was significant difference(Z=-4.015,P＜0.001).The correlation between AT and emphysema parameters of the voxel-based method and PFT parameters (r=-0.399 and-0.494,-0.335 and-0.439 separately,P＜0.05) were higher than that of the conventional threshold method,respectively (r=-0.357 and-0.453,-0.284 and-0.391,respectively;all P＜0.05).Furthermore,the voxel-based method can classify COPD patients with similar degree of pulmonary function injury into three subtypes:AT-dominant,emphysema-dominant,and mixed.Conclusions The voxel-based AT quantitative measurement method not only has high sensitivity and accuracy,but also provides imaging phenotype for the diagnosis of COPD and provides assistant decision-making for clinical management.
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In pediatric thoracic CT, respiratory motion is generally treated as a motion artifact degrading the image quality. Conversely, respiratory motion in the thorax can be used to answer important clinical questions, that cannot be assessed adequately via conventional static thoracic CT, by utilizing four-dimensional (4D) CT. However, clinical experiences of 4D thoracic CT are quite limited. In order to use 4D thoracic CT properly, imagers should understand imaging techniques, radiation dose optimization methods, and normal as well as typical abnormal imaging appearances. In this article, the imaging techniques of pediatric thoracic 4D CT are reviewed with an emphasis on radiation dose. In addition, several clinical applications of pediatric 4D thoracic CT are addressed in various thoracic functional abnormalities, including upper airway obstruction, tracheobronchomalacia, pulmonary air trapping, abnormal diaphragmatic motion, and tumor invasion. One may further explore the clinical usefulness of 4D thoracic CT in free-breathing children, which can enrich one's clinical practice.
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Child , Humans , Airway Obstruction , Artifacts , Four-Dimensional Computed Tomography , Thorax , Tomography, X-Ray Computed , TracheobronchomalaciaABSTRACT
Hypersensitivity pneumonitis(HP) is a diffuse granulomatous interstitial lung disease caused by the inhalation of specific organic antigens or low molecular weight substances in genetically susceptible individuals. In general, HP is difficult to diagnose because of its nonspecific clinical manifestations as well as imaging and histological features similar to other interstitial lung diseases. HP is divided into three phases, while the imaging performance between the three phases overlaps. As a key means of differential diagnosis between chronic HP and ILD, high-resolution computed tomography(HRCT) is the most sensitive test for HP, especially in case where clinical lung biopsy is not available. This article reviews the essential features of HP with emphasis on imaging features, mainly to classify and summarize HP's various imaging performances, hoping to provide early diagnosis leads for the clinic.
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Objective To explore airway remodeling and air trapping in asthmatic patients with low dose CT scanning and quantitative analysis. Methods 52 stable asthmatic patients in which 29 were severe and 23 were slight,and 20 healthy control cases were underwent low dose dual phase CT scanning. The LA/BSA, WA/BSA, TA/BSA, WA%and Pi10WA were analyzed as airway remolding indexes. The MLD of expiratory, VI-850 (%) of expiratory, MLD E/I, VI-850E-I (%) and VI-850/-950E-I (%) were analyzed as air-trapping indexes. One-Way ANOVA or H Kruskal-Wallis was used to analyze the above indicators. Results Airway remodeling indexes and LA/BSA were (9.6 ± 2.6), (11.0 ± 3.4) and (12.6 ± 3.0)mm2/m2 in severe asthmatics group, non-severe asthmatics group and healthy control group respectively, and there was significant difference between the three groups (F=5.60, P=0.006). WA%of each group was (65.1 ± 2.5)%, (63.3 ± 4.4)%and (62.0 ± 3.0)%, and there was significant difference between the three groups (F=5.53,P=0.006). The Pi10WA was (18.4±2.6), (17.7±3.1) and (16.4±1.4) mm2 respectively with significant difference between the three groups (F=3.59 ,P=0.033). Air-trapping indexes, MLD of expiratory of each group was-(771 ± 59),-(724 ± 43) and-(676 ± 60) HU respectively with significant difference (F=5.60, P=0.006). VI-850(%) of expiratory of each group was 30.79(30.45)%, 13.53(12.09)%and 2.85(6.87)%respectively with significant difference (H=17.20,P<0.001). Conclusions Low dose of CT scan and quantitative analysis can provide an objective and quantitative information for patients with airway disease of asthma, and both WA% and Pi10WA were objective indexes. The severe asthmatic patients were associated with obvious airway remodeling and air trapping compared with non-severe asthmatic patients.
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Objective To evaluate the extent and anatomic distribution of air trapping in lung in young asymptomatic female subjects to achieve early diagnosis of small airway diseases.Methods Fifty young females with normal pulmonary function were included retrospectively in this study.All subjects underwent both inspiratory and expiratory CT scans,the percentage of the area of air trapping(AT)and the percentage of the area of emphysema(Emph)were quantitatively analyzed.Comparison between bilateral lungs was analyzed using independent-samples t test;Comparisons among lobes were done using one-way ANOVA or Kruskal-Wallis rank sum test;Pairwise comparisons between lobes were conducted using LSD test or paired comparison;The effects of each lobe on AT were analyzed using Spearman's rank correlation coefficient,simple linear regression and multiple stepwise regression.Results There was a certain degree of air trapping in lung and a small amount of emphysema in young asymptomatic females.Air trapping was mainly located in the right middle lobe (RML)and bilateral upper lobes.The ratio of air trapping to volume was the highest in RML and the change of air trapping in the bilateral upper lobes had the greatest influence on the air trapping degree of the whole lung.Conclusion There is a certain degree of air trapping in lung in young asymptomatic females.The occurrence and development of air trapping in RML may be a sensitive biomarker for the early detection of pathophysiological changes in small airway diseases using imaging procedures.
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OBJECTIVE: The purpose of this study was to compare air trapping in healthy volunteers with asthmatics using pulmonary function test and quantitative data, such as specific volume change from paired inspiratory CT and registered expiratory CT. MATERIALS AND METHODS: Sixteen healthy volunteers and 9 asthmatics underwent paired inspiratory/expiratory CT. DeltaSV, which represents the ratio of air fraction released after exhalation, was measured with paired inspiratory and anatomically registered expiratory CT scans. Air trapping indexes, DeltaSV0.4 and DeltaSV0.5, were defined as volume fraction of lung below 0.4 and 0.5 DeltaSV, respectively. To assess the gravity effect of air-trapping, DeltaSV values of anterior and posterior lung at three different levels were measured and DeltaSV ratio of anterior lung to posterior lung was calculated. Color-coded DeltaSV map of the whole lung was generated and visually assessed. Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 were compared between healthy volunteers and asthmatics. In asthmatics, correlation between air trapping indexes and clinical parameters were assessed. RESULTS: Mean DeltaSV, DeltaSV0.4, and DeltaSV0.5 in asthmatics were significantly higher than those in healthy volunteer group (all p < 0.05). DeltaSV values in posterior lung in asthmatics were significantly higher than those in healthy volunteer group (p = 0.049). In asthmatics, air trapping indexes, such as DeltaSV0.5 and DeltaSV0.4, showed negative strong correlation with FEF25-75, FEV1, and FEV1/FVC. DeltaSV map of asthmatics showed abnormal geographic pattern in 5 patients (55.6%) and disappearance of anterior-posterior gradient in 3 patients (33.3%). CONCLUSION: Quantitative assessment of DeltaSV (the ratio of air fraction released after exhalation) shows the difference in extent of air trapping between health volunteers and asthmatics.
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Adult , Aged , Female , Humans , Male , Middle Aged , Asthma/physiopathology , Exhalation/physiology , Healthy Volunteers , Lung/physiopathology , Respiratory Function Tests , Tomography, X-Ray Computed/methodsABSTRACT
Objective To determine whether bronchiolitis obliterans syndrome (BOS) after bone marrow transplantation can be predicted in light of air trapping. Methods Thirty-three cases of BOS (BOS group) and 111 normal patients (normal group) were comparatively reviewed for the CT characteristics (including frequency, dynamic change and diagnostic potency) of air trapping. The analysis was mainly based on the last CT scans before occurrence of BO.S. Results The frequency of air trapping, especially mosaic air trapping or extensive air trapping, was higher in the BOS group than in the normal group (P = 0. 03). The median total air trapping scorewas higher in the BOS group than in the normal group (P = 0. 01). The increase of air trapping extent with the progress of disease was more common in the BOS group (50. 0%, 9/18), whereas a decrease of air trapping extent, disappearance or intermittent appearance of air trapping was more common in the normal group (60. 0%, 15/ 25) during the follow-up period. When mosaic air trapping or extensive air trapping was used as the diagnostic threshold, the specificity was high (90.5%, 96.7%), but the sensitivity was low (29. 4%, 15. 8%). Conclusion Occurrence of air trapping is a clue for development of BOS in patients receiving bone marrow transplantation. Mosaicair trapping and extensive air trapping are insensitive but specific CT findings.
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La tomografía computada de alta resolución representa una herramienta fundamental en la evaluación de los pacientes con diagnostico de Fibrosis Quística, siendo en la actualidad la modalidad de imagen de elección. Revisamos las anomalías más frecuentes y su aspecto tomográfico reportando los hallazgos en pacientes de nuestra institución.
High Resolution Computed Tomography represents an important tool in the evaluation of patients with Cystic Fibrosis, being the imaging choice method. We review and report the tomographic findings of the most important anomalies in patients of our institution.
Subject(s)
Adolescent , Adult , Cystic Fibrosis , Tomography, X-Ray Computed/methods , Pulmonary Atelectasis , Bronchiectasis , Vital Capacity/physiology , Respiratory MucosaABSTRACT
PURPOSE: We wanted to evaluate whether there is any different finding on CT with aging for the patients suffering with adult Swyer-James-MacLeod Syndrome (SJMS). MATERIALS AND METHODS: We included 11 patients (7 males and 4 females) who underwent chest CT scan among 18 patients who were suspected of suffering with SJMS on chest radiographs. The range of age was from 28 to 85 years (mean: 58.5). We evaluated the diameter of both the main pulmonary artery (MPA) with its ratio, and the diameter of the pulmonary trunk (PT) to evaluate the possibility of pulmonary arterial hypertension, and the presence or absence of bronchiectasis. We also evaluated the relationships between these findings and aging. RESULTS: SJMS affected the left lung in 10 of 11 patients. The mean diameter of the main pulmonary artery of the normal lung was 2.5 cm and it was 1.6 cm in the involved site. The mean ratio of the normal MPA diameter to the involved one was 1.6 and this did not correlate with age (p>0.1). The mean diameter of the pulmonary trunk was 2.8 cm and this increased with age (p0.5). CONCLUSION: SJMS absolutely affected the left lung much more than the right lung. All the patients demonstrated about 1.6 times the compensatory hypertrophy of MPA of the normal lung compared with that of the affected lung on chest CT, which was irrespective of age. The presence or absence of bronchiectasis has no correlation with age.
Subject(s)
Adult , Humans , Male , Aging , Bronchiectasis , Bronchiolitis , Hypertension , Hypertrophy , Lung , Pulmonary Artery , Radiography, Thoracic , Tomography, X-Ray ComputedABSTRACT
PURPOSE: The purposes of this study were to determine the abnormal high-resolution computed tomography(HRCT) findings of the lung in uncomplicated asthmatic children, to compare the clinical characteristics between normal and abnormal HRCT finding groups and to correlate abnormal HRCT findings with clinical characteristics, especially FEV1 and PC20. METHODS: Forty asthmatic children were studied. Inspiratory and expiratory HRCT scans were performed on all patients. Pulmonary function tests and methacholine challenge tests were done and total eosinophil counts and total IgE level were checked during the symptom-free period. According to the presence of abnormality in HRCT findings, the subjects were divided into two groups : Normal and abnormal HRCT finding group. Clinical characteristics, severity of asthma, FEV1 and PC20 were compared between the two groups. RESULTS: Abnormal HRCT findings were air trapping, fibrosis, bronchial dilatation, and bronchial wall thickening. Air trapping was the most prevalent finding(50%). Significant differences in total IgE level(P< 0.05), severity of asthma(P< 0.05), FEV1(P< 0.05) and PC20(P< 0.05) were found between patients with abnormal HRCT findings and those with normal HRCT findings. Air trapping scores were significantly correlated with FEV1(r=-0.469, P< 0.05) and PC20(r=-0.315, P< 0.05). CONCLUSION: Air trapping was detected in 50% of uncomplicated asthmatic children and air trapping scores were correlated well with the extent of airflow obstruction and the degree of airway hyperresponsiveness. Our data suggest that the extent of air trapping found on HRCT scans reflects the severity of asthma and airway hyperresponsiveness in asthmatic patients.