PURPOSE: To evaluate the usefulness of spiral CT in the measurement of lung volumes. MATERIALS AND METHODS: Fifteen healthy volunteers were studied by both spirometer and spiral CT at full inspiration and expiration inorder to correlate their results, including total lung capacity (TLC), vital capacity (VC) and residual volume(RV). 3-D images were reconstructed from spiral CT, and we measured lung volumes at a corresponding CT window range ; their volumes were compared with the pulmonary function test (paired t-test). RESULTS: The window range corresponding to TLC was from -1000HU to -150HU (p=0.279, r=0.986), and for VC from -910HU to -800HU (p=0.366,r=0.954) in full-inspiratory CT. The optimal window range for RV in full-expiratory CT was from -1000HU to -450HU (p=0.757, r=0.777), and TLC-VC in full-inspiratory CT was also calculated (p=0.843, r=0.847). CONCLUSION: Spiral CT at full inspiration can used to lung volumes such as TLC, VC and RV.
Healthy Volunteers ; Imaging, Three-Dimensional ; Lung* ; Respiratory Function Tests ; Tomography, Spiral Computed* ; Total Lung Capacity ; Vital Capacity

Lung Volumes and alveolorespiratory function were studied in 30 cases of pure or predominat mitral stenosis in slightly to moderately compromized state, and the results were compared with those in the normal controls. In patients with mitral stenosis, there was a singnificant reduction in the vital capcity and the total lung capacity, whereas the residual volume and its ratio to the total lung capacity were significantly increased. The distribution of inspired gas was uneven as reflected by increase in the lung clearnace index and in the slope of phase III of the single breath nitrogen washout curve. The alvelolar arterial oxygen tension gradient and the physiological dead space were singinificantly increased despite a singinificant decrease in the arterial carbon dioxide tension. The diffusing capacity was also reduced in some cases.
Carbon Dioxide ; Humans ; Lung* ; Mitral Valve Stenosis* ; Nitrogen ; Oxygen ; Residual Volume ; Total Lung Capacity

PURPOSE: To determine the potential of spiral CT as a functional imaging modality of the lung asid from its proven value in morphological depiction. MATERIALS AND METHODS: Spiral CT scan was performed in ten normal female and nine normal male adults (mean age: 39, height: 163cm, weight: 62kg) after single full breath-holding. Three dimensional lung images were reconstructed (minimal threshold value: -1,000HU, maximal threshold values: -150,-250, -350, -450HU) to obtain total lung volume(TLV) on a histogram. Total lung volume measured by spiral CT was compared with TLV obtained by spirometry. RESULTS: Mean TLV measured by spirometry was 5.62 Land TLV measured by CT at maximal threshold values of -150, -250, -350, and -450HU was 6.63, 5.33, 5.15, and 4.98 L, respectively. Mean absolute differences between the modalities of 0.17L(3%), 0.32L(5.6%), 0.48L(8.5%), 0.65L(11.5) were statistically significant(p<0.001). Linear regression coefficients between the modalities were 0.99, 0.97, 0.95,and 0.94 and no statistically significant differences in accuracy of threshold levels in the estimation of lung volume(r=0.99, standard error=0.034L in all) were seen. CONCLUSION: TLV measured by spiral CT closely approximated that measured by spirometry. Spiral CT may be useful as a means of evaluating lung function.
Adult ; Female ; Humans ; Linear Models ; Lung ; Male ; Spirometry* ; Tomography, Spiral Computed* ; Total Lung Capacity*

BACKGROUND: The lung volume and diffusing capacity are influenced by ethnicity. However, there are no equations for predicting the normal lung volume in the adult Korean population, and there is only one equation for diffusing capacity. The aim of this study is to select the most suitable reference equation for the Korean population. METHOD: 30 men and 33 women at Hanyang University Guri Hospital, and 27 men and 34 women at Asan Medical Center in healthy nonsmoking adults were enrolled in this study. The subject's age, gender, height, weight, lung volume by plethysmography, and diffusing capacity by a single breathing method were obtained. The most suitable equation with the lowest sum of residuals between the observed and predicted values for lung volume and diffusing capacity was selected. RESULT: At Hanyang University Guri Hospital, the equations with the lowest sum of residuals in the total lung capacity were ECSC's equation in males (sum of residual: 0.04 L) and Crapo/Morris's equation (-1.04) in women. At the Asan Medical Center, the equations with the lowest sum of residuals in the total lung capacity were Goldman/Becklake's equation in males (sum of residual: -2.35) and the ECSC's equation -4.49) in women. The equations with the lowest sum of residuals in the Diffusing capacity were Roca's equation in males (sum of residual: -13.66 ml/min/mmHg) and Park's in women (25.08) in Hanyang University Guri hospital and Park's equation in all cases in the Asan Medical Center (male: -1.65 , female: -6.46). CONCLUSIONS: Until a reference equstion can be made for healthy Koreans by sampling, ECSC's equation can be used for estimating the lung volume and Park's can be used for estimating the diffusing capacity.
Adult ; Chungcheongnam-do ; Female ; Humans ; Korea* ; Lung* ; Male ; Plethysmography ; Respiration ; Total Lung Capacity

BACKGROUND: Low spirometric forced vital capacity(FVC) in conjunction with a normal or high ratio of the forced expiratory volume at 1 second to the forced vital capacity(FEV1/FVC%) has traditionally been classified as a restrictive abnormality. However, the gold-standard diagnosis of a restrictive pulmonary impairment requires a measurement of the total lung capacity (TLC). This study was performed to determine the predictive value of spirometric measurements of the FVC for diagnosing a restrictivepulmonary abnormality. METHODS: Test results from 1,371 adult patients who undertook both spirometry and lung volume measurements on the same visit from January 1999 to December 2000 were enrolled in this study. The test values for the FVC, the TLC that was below 80% of predicted value, and a FEV1/FVC% that was below 70%, were classified as being abnormal. RESULTS: Of the 1,371 patients, 353 patients had a reduced a FVC. Of these patients, 186 patients had a reduced TLC. Therefore, the positive predictive value was 52.7%. Of the 196 patients with a normal FEV1/FVC% and a reduced FVC, 148(75.5%) patients had a lower TLC. Thirty eight (24.2%) patients out of 157 patients with a low FEV1/FVC% and a low FVC showed a restrictive defect. CONCLUSION: Spirometry is useful to rule out a restrictive pulmonary abnormality, but a restrictive pattern on the spirometry dose not mean there is a true restrictive disease. For the patients with a low FVC, TLC measurements are essential for diagnosing a restrictive pulmonary impairment.
Adult ; Diagnosis ; Forced Expiratory Volume ; Humans ; Lung Volume Measurements ; Plethysmography, Whole Body ; Respiratory Function Tests ; Spirometry* ; Total Lung Capacity ; Vital Capacity

BACKGROUND: There are reports that food deprivation causes emphysematous changes in the lungs of rats and humans. However, the meaning of this phenomenon in patients with chronic obstructive pulmonary disease has not been evaluated. The aim of this study was to determine the correlations between the caloric intake and parameters of the lung function in patients with chronic obstructive pulmonary disease. METHODS: Patients with chronic obstructive pulmonary disease who had visited the respiratory clinic from March, 2006 for one year were enrolled in this study. The patients underwent pulmonary function tests, and a dietitian evaluated their nutritional intake using a food record method. RESULTS: There was no correlation between the total caloric intake and forced vital capacity (FVC, %predicted) or forced expiratory volume in one second (FEV1, %predicted). The total caloric intake showed a positive correlation with the diffusing capacity of carbon monoxide (DLCO %predicted, DLCO/VA %predicted), and a negative correlation with the total lung capacity (TLC, %predicted). Of the calories taken, only calories from protein intake correlated with the diffusing capacity of carbon monoxide (DLCO %predicted, DLCO/VA %predicted). CONCLUSION: The total caloric intake of patients with chronic obstructive pulmonary disease showed a positive correlation with the diffusing capacity of the lung, and a negative correlation with the total lung capacity. Further study on the linkage between the caloric intake and severity of emphysema is needed.
Animals ; Carbon Monoxide ; Emphysema ; Energy Intake ; Food Deprivation ; Forced Expiratory Volume ; Humans ; Lung ; Pulmonary Disease, Chronic Obstructive ; Rats ; Respiratory Function Tests ; Total Lung Capacity ; Vital Capacity

BACKGROUND: A lung bulla may rarely shrink as a result of an inflammation within the bulla or a closing of a bronchus involved in the inflammation process, which is termed 'autobullectomy'. The purpose of this study was to describe clinical features of patients with regressions of bullae during follow-up. METHODS: We retrospectively reviewed the cases and individuals who showed unequivocal evidence of interval regressions in a pre-existing bulla. A total of 477 cases with a bulla >5 cm in diameter were screened manually. Thirty cases with bullae that showed regression during follow-up were selected. RESULTS: Regressions of large bullae occurred in 30 of 477 cases (6.3%). The median age of those patients was 61 (range, 53~66) years and 87% of those patients were men. The main cause of a bulla was emphysema (80%). Among 30 cases, 16 cases had pneumonia in the lung parenchyma of the peribullous area. Another 7 cases had a regressed bulla accompanied by an air-fluid level within the bulla. The remaining 7 cases showed a spontaneous regression of the bulla without such events. Complete regression of a bulla occurred in 25 cases. A follow-up chest-X ray showed that in all cases except one, the bulla remained in a collapsed state after 24 months. Forced expiratory volume in one second (FEV1) improved in 3 cases and the other 2 cases had increased forced vital capacity (FVC). In addition, total lung capacity (TLC) and residual volume (RV) decreased in another 2 cases. CONCLUSION: Regression of a lung bulla occurred not only after pneumonia or the presence of air-fluid level within the bulla, but also without such episodes. The clinical course of regression of a lung bulla varied. After regression of a bulla, lung function could be improved in some cases.
Blister ; Bronchi ; Emphysema ; Follow-Up Studies ; Forced Expiratory Volume ; Humans ; Inflammation ; Lung ; Male ; Pneumonia ; Pulmonary Emphysema ; Remission, Spontaneous ; Residual Volume ; Retrospective Studies ; Total Lung Capacity ; Vital Capacity

BACKGROUND: It is most physiologic to measure the diffusing capacity of the lung by using oxygen, but it is so difficult to measure partial pressure of oxygen in the capillary blood of the lung that in clinical practice it is measured by using carbon monoxide, and single-breath diffusing capacity method is used most widely. However, since the process of withholding the breath for 10 seconds after inspiration to the total lung capacity is very hard to practice for patients who suffer from cough, dyspnea, etc, the intrabreath lung diffusing capacity method which requires a single exhalation of low-flow rate without such process was devised. In this study, we want to know whether or not there is any significant difference in the diffusing capacity of the lung measured by the single-breath and intra-breath methods, and if any, which factors have any influence. METHODS: We chose randomly 73 persons without regarding specific disease, and after conducting 3 times the flow-volume curve test, we selected forced vital capacity(FVC), percent of predicted forced vital capacity, forced expiratory volume within 1 second(FEV1), percent of forced expiratory volume within 1 second, the ratio of forced expiratory volume within 1 second against forced vital capacity(FEV1/FVC) in test which the sum of FVC and FEV1 is biggest. We measured the diffusing capacity of the lung 3 times in each of the single-breath and intra-breath methods at intervals of 5 minutes, and we evaluated which factors have any influence on the difference of the diffusing capacity of the lung between two methods[the mean values(ml/min/mmHg) of difference between two diffusing capacity measured by two methods] by means of the linear regression method, and obtained the following results: RESULTS: 1) Intra-test reproducibility in the single-breath and intra-breath methods was excellent. 2) There was in general a good correlation between the diffusing capacity of the lung measured by a single-breath method and that measured by the intra-breath method, but there was a significant difference between values measured by both methods(l.0l+/-0.35ml/min/mmHg, p<0.01) 3) The differnce between the diffusing capacity of the lung measured by both methods was not correlated to FVC, but was correlated to FEV1, percent of FEV1, FEV1/FVC and the gradient of methane concentration which is an indicator of distribution of ventilation, and it was found as a result of the multiple regression test, that the effect of FEV1/FVC was most strong(r=-0.4725, p<0.01) 4) In a graphic view of the difference of diffusing capacity measured by single-breath and intra-breath method and FEV1/FVC, it was found that the former was divided into two groups in section where FEV1/FVC is 50~60%, and that there was no significant difference between two methods in the section where FEV1/FVC is equal or more than 60% (0.05 +/-0.24ml/min/mmHg, p>0.1), but there was significant difference in the section, less than 60%(-4.5+/-0.34ml/min/mmHg, p <0.01). 5. The diffusing capacity of the lung measured by the single-breath and intra-breath method was the same in value(24.3 +/-0.68ml/min/mmHg) within the normal range(2%/L) of the methane gas gradient, and there was no difference depending on the measuring method, but if the methane concentration gradients exceed 2%/L, the diffusing capacity of the lung measured by single-breath method became 15.0+/-0.44ml/min/mmHg, and that measured by intra-breath method, 11.9+/-0.5 1ml/min/mmHg, and there was a significant difference between them(p<0.01). CONCLUSION: Therefore, in case where FEV1/FVC was less than 60%, the diffusing capacity of the lung measured by intra-breath method represented significantly lower value than that by single-breath method, and it was presumed to be caused largely by a defect of ventilation- distribution, but the possibility could not be excluded that the diffusing capacity of the lung might be overestimated in the single-breath method, or the actual reduction of the diffusing capacity of the lung appeared more sensitively in the intra-brerath method.
Capillaries ; Carbon Monoxide* ; Carbon* ; Cough ; Dyspnea ; Exhalation ; Forced Expiratory Volume ; Humans ; Linear Models ; Lung* ; Methane ; Oxygen ; Partial Pressure ; Total Lung Capacity ; Ventilation ; Vital Capacity

OBJECTIVESTo compare the difference in pulmonary function between Caucasians and Chinese and assess the best reference values of pulmonary function for Chinese adults.

METHODSValues for pulmonary function were predicted by tests on 4773 Chinese healthy subjects (male: 2560, female: 2213, aged 15-78 years) in six parts (north, northeast, northwest, east, southwest and south) of China. Prediction equations of the European Community for Steel and Coal (ECSC), other equations for overseas Chinese or for Caucasians were also selected. The regression coefficients of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC, total lung capacity (TLC) and residual volume (RV) were summarized.

RESULTSECSC predictions were closer to the Chinese ones than other selected equations. Comparison with ECSC predictions showed that on average the values for FVC, FEV1 were 5.3% smaller in Chinese males and 3.3% smaller in Chinese females, with the maximal differences in south China and the minimal differences in North China. RV and TLC in Chinese were lower than in Caucasians (males 4.8%, 5.5%, respectively; females 8.7% and 6.0%, respectively). Conversion factors were given for adjusting ECSC equations to fit Chinese.

CONCLUSIONSFor predicting values of pulmonary function in Chinese, we suggest to use the equations reported here. Alternatively, ECSC regression equations may be used with appropriate conversion factors.

Adolescent ; Adult ; Aged ; Female ; Forced Expiratory Volume ; Humans ; Lung ; physiology ; Male ; Middle Aged ; Reference Values ; Regression Analysis ; Total Lung Capacity ; Vital Capacity

BACKGROUND: With cases of chronic obstructive pulmonary disease(COPD), weight loss and low body weight have been found to correlate with increased mortality and poor prognosis. Therefore, nutritional aspects are an important part of the treatment in cases of COPD. In Korea, there is only limited data available for the changes of resting pulmonary function in relation to nutritional status. This study was carried out to investigated the differences of resting pulmonary function in relation to the nutritional status of patients with COPD. METHOD: 83 stable patients, with moderate to severe COPD, were clinically assessed for their nutritional status and resting pulmonary function. The patients' nutritional status was evaluated by body weight and fat-free mass (FFM), which was assessed by bioelectrical impedance analysis. According to their nutritional status, the 83 patients were divided into two groups, designated as the depleted, and non-depleted, groups. RESULT: Of the 83 patients, 31% were characterized by body weight loss and depletion of FFM, whereas 28% had either weight loss or depleted FFM. In the depleted group, significantly lower peak expiratory flow rate(p<0.05) and Kco(p<0.01), but significantly higher airway resistance(Raw, p<0.05) were noted. There was no difference for the non-depleted group in forced expiratory volume at one second, residual volume, inspiratory vital capacity, or total lung capacity. Maximal inspiratory pressure(PImax) was also significantly lower in the depleted group(p<0.05). CONCLUSION: We conclude, from our clinical studies, that nutritional depletion is significantly associated with the change in resting pulmonary function for patients with moderate to severe COPD.
Body Weight ; Electric Impedance ; Forced Expiratory Volume ; Humans ; Korea ; Mortality ; Nutritional Status* ; Prognosis ; Pulmonary Disease, Chronic Obstructive* ; Residual Volume ; Total Lung Capacity ; Vital Capacity ; Weight Loss