PURPOSE: To separately evaluate the respiratory function of both lungs separately in patients with unilateralmain bronchial stenosis or obstruction, applying respiratory dynamic CT using the spiral technique. MATERIALS AND METHODS: This study involved five normal subjects and six patients with main bronchial stenosis. Time-continuous scan data at a selected levels during forced vital capacity maneuver were obtained, and static images were retrospectively reconstructed using 0.67 sec. partial scan data per image. Time-density curves for controls and patients were plotted and compared. RESULTS: The highest values of mean attenuation were -697+/-9 H for the leftlung and -684+/-9 H for the right lung of controls, and -697+/-5HU for the healthy lung and -791+/-3H for thediseased lung of the patients. The lowest values were -837+/-2H for the left lung and -842+/-5H for the right lungof contorls, and -847+/-0H for the healthy lung and -858+/-4H for the diseased lung of patients. Mean durations ofexpiration were 1.64+/-.65 seconds for the left lung and 1.58+/-.50 seconds for the right lung of controls, and1.66+/-.60 seconds for the healthy lung and 1.96±.49 seconds for the diseased lung of patients. Time-attenuationcurves for the right and left lung of controls were not significautly different, but except for the lowest value of mean attenuation, these were signficantly different for the healthy and diseased longs of patients. CONCLUSION: Respiratory dynamic CT is an updated technique which permits imaging of the functional status of lung parenchy maduring respiration. It may be useful in the evaluation and quantification of lung function in patients with proximal airway stenosis.
Constriction, Pathologic* ; Humans ; Lung ; Respiration ; Vital Capacity

BACKGROUND: It has been sugested that excessive airway narrowing in asthma may be detected by a decrease in forced vital capacity (FVC). A volume differrence between slow vital capacity (SVC) and FVC may be used as a surrogate index of airway collapse. OBJECTIVE: To investigate the relationship between an airway collapsibility index (CI) and airflow limitation or airway hyperresponsiveness in asthma. METHODS: Forty-six patients with suspected asthma and 21 normal control subjects were enrolled. CI was defined as a difference between SVC and FVC, and measured before and after a methacholine (MCh) bronchoprovocation test. Positive response to MCh was defined as a fall of FEV1 by more than 12%. RESULTS: CI significantly increased from 1.10+/-3.86% to 5.52+/-7.91% after MCh in the positive MCh group (n=19, p<0.01). Not only FVC but also SVC was significantly decreased after MCh. One-fifth of the decrease in FVC was caused by the increase in CI. Both FVC and SVC were significantly related to baseline FEV1 values and in percent change after MCh. Although CI was also significantly related to FEV1 in percent change after MCh. CI was significantly higher in the positive MCh group than in the control and was not significantly related to baseline FEV1 values. Furthermore, the relationship of CI values between before and after MCh was significant (r=0.622, p<0.01). CI was not significantly different according to the severity of MCh-PC20. CONCLUSION: Because the relationship between CI and the severity of airflow limitation or MCh-PC20 was less significant. CI may be better than FVC to represent the characteristic of excessive airway narrowing in asthma.
Asthma* ; Humans ; Methacholine Chloride ; Vital Capacity

The chronic obstructive pulmonary disease (COPD) can be diagnosed by spirometry. COPD is confirmed when a patient who has symptoms that are compatible with COPD is found to have airflow obstruction (post expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio less than 0.70). However, the FEV1/FVC ratio decreases with age and can create a risk for underdiagnosis in young patients an overdiagnosis in older patients. Therefore, clear consensus definition of diagnostic criteria for COPD in older patients is needed. The staging system using FEV1 alone has been criticized for underestimating the importance of the extrapulmonary manifestation of COPD in predicting outcome. The BODE (Body mass index, Obstruction, Dyspnea, Exercise capacity) index provides better prognostic information than the FEV1 alone and can be used to assess therapeutic response.
Consensus ; Dyspnea ; Humans ; Pulmonary Disease, Chronic Obstructive ; Spirometry ; Vital Capacity

Respiratory muscle training is one of the major methods for enhancing the vocal function. Singers who must use their voice most frequently are well aware of the importance of respiration. However, most of them do not know precisely how to exercise their abdominal respiration. Using a respiratory training device, singers are expected to gain more efficiency in their vocal enhancement. The aim of the study was to examine the pulmonary function, the maximum inspiratory pressure (MIP) and the maximum expiratory pressure (MEP), and the maximum phonation time (MPT) in five female voice-majors students after undergoing specially programmed respiratory muscle training for 2 months. All the voice-majors had an average of 4.8 years of formal classical voice training. A respiratory muscle training device (Ultrabreathe (R) ), Tangent health Care Inc., England) was used to train the respiratory muscle. None of the pulmonary function test variables had changed after respiratory muscle training. However, the MIP, MEP, and MPT were significantly increased higher after the respiratory muscle training. This suggests that the specially programmed respiratory muscle training can improve the respiratory muscle strength and vocal function without increasing the pulmonary function.
Adult ; *Breathing Exercises ; Female ; Humans ; *Phonation ; Pressure ; Vital Capacity ; Voice

PURPOSE: To analyze high-resolution CT findings(HRCT) of pulmonary lymphangitic carcinomtosis(PLC) and to correlated the HRCT findings with the results of pulmonary function test(PFT). MATERIALS AND METHODS: In Twenty eight patients with radiologically and clinically proved PLC, we retrospectively reviewed HRCT scans and PFT(N=12). PLC was classified by extent and distribution of metastatic nodules and interstitial thickenings on HRCT and the findings were correlated with the results of PFT and impairment of PFT according to the degree of FEVl(forced expiratory volume in one second). RESULTS: On the basis of distribution of PLC, HRCT findings showed 20 cases of peripheral type, 3 cases of central type, and 5 cases of mixed type. In the patients with PFT diffuse type was 10 cases and localized type was 2 cases. In diffuse types, the restrictive pattern occurred in 7 cases (p<0.05) and in localized types, restrictive pattern occurred in 2 cases. Marked impairment of vital capacity was shown as restrictive pattern in 7 cases all of which were diffuse type and were consisted of peripheral type in 4 cases and mixed type in 3 cases. CONCLUSION: HRCT findings of lymphangitic carcinomatosis correlated well the type and degree of impairment of PFT. Especially in diffuse type of lymphangitic carcinomatosis, the result of pulmonary function test were prominent restrictive patterns. Marked impairment of pulmonary function occurred in patients with diffuse type and types with peripheral interstitial thickening(periphral and mixed types).
Carcinoma* ; Humans ; Respiratory Function Tests* ; Retrospective Studies ; Vital Capacity

BACKGROUND: When patients with chronic respiratory symptoms have a normal spirometry result, it is not always easy to consider bronchial asthma as the preferential diagnosis. Forced expiratory flow between 25% and 75% of vital capacity (FEF(25~75%)) is known as a useful diagnostic value of small airway diseases. However, it is not commonly used, because of its high individual variability. We evaluated the pattern of bronchodilator responsiveness (BDR) and the correlation between FEF25~75% and BDR in patients with suspicious asthma and normal spirometry. METHODS: Among patients with suspicious bronchial asthma, 440 adult patients with a normal spirometry result (forced expiratory volume in one second [FEV1]/forced vital capacity [FVC] > or =70% & FEV1% predicted > or =80%) were enrolled. We divided this group into a positive BDR group (n=43) and negative BDR group (n=397), based on the result of BDR. A comparison was carried out of spirometric parameters with % change of FEV1 after bronchodilator (DeltaFEV1%). RESULTS: Among the 440 patients with normal spirometry, FEF(25~75%)% predicted were negatively correlated with DeltaFEV1% (r=-0.22, p<0.01), and BDR was positive in 43 patients (9.78%). The means of FEF(25~75%)% predicted were 64.0+/-14.5% in the BDR (+) group and 72.9+/-20.8% in the BDR (-) group (p<0.01). The negative correlation between FEF(25~75%)% predicted and DeltaFEV1% was stronger in the BDR (+) group (r=-0.38, p=0.01) than in the BDR (-) group (r=-0.17, p<0.01). In the ROC curve analysis, FEF(25~75%) at 75% of predicted value had 88.3% sensitivity and 40.3% specificity for detecting a positive BDR. CONCLUSION: BDR (+) was not rare in patients with suspicious asthma and normal spirometry. In these patients, FEF(25~75%)% predicted was well correlated with BDR.
Adult ; Asthma ; Bronchodilator Agents ; Humans ; ROC Curve ; Spirometry ; Vital Capacity

OBJECTIVE: To evaluate the effect of the air stacking exercise on maximal insufflation capacity (MIC) and peak cough flow (PCF) in patients with neuromuscular diseases. METHOD: Two hundred twenty nine neuromuscular patients with vital capacity (VC) below 50% of the predicted normal value were initially evaluated for VC, MIC, PCF, and assisted PCF (APCF). After the first evaluation, these patients were instructed to carry out air stacking exercise periodically, and were re-evaluated after one year. RESULTS: Forty seven patients were capable of performing air stacking exercise on regular basis, at least twice a day for one year. Among these patients, MIC increased in 28 patients from 1345.4 ml to 1572.9 ml on average (p<0.05), while it decreased in 19 patients from 1740.0 ml to 1325.3 ml on average (p<0.05). In the increasing MIC group APCF increased from 244.6 L/min to 278.1 L/min (p<0.05). In the decreasing MIC group, every value decreased significantly. CONCLUSION: Air stacking exercise was shown to be capable of increasing MIC and APCF despite the reduction in VC and PCF in patients with neuromuscular diseases.
Cough ; Humans ; Insufflation ; Neuromuscular Diseases* ; Reference Values ; Vital Capacity

PURPOSE: The purpose of this study was to determine the effects of a chair backrest on respiratory function after prolonged sitting. METHODS: Twenty-four young healthy subjects (12 males and 12 females) volunteered to participate in this study, and were equally allocated to a backrest (n=12) or a without backrest group (n=12). A spirometer was used to measure the respiratory functions of all subjects. RESULTS: The chair with backrest group were significant difference in forced vital capacity (FVC), Forced expiratory volume in 1 second (FEV1), and peak expiratory flow (PEF) after sitting for 1 hour, compared with chair without backrest group (p < 0.05). The chair with backrest group showed a significantly decreased in FVC, FEV1, and PEF. CONCLUSION: Using a chair without a backrest may help to reduce lung function deterioration as compared with a chair with a backrest.
Forced Expiratory Volume ; Healthy Volunteers ; Humans ; Lung ; Male ; Vital Capacity

A kind of portable device for detecting common lung function parameters is mentioned in this paper. Using the singlechip microcomputer as the master control block to collect and process the data from high-accuracy gas pressure sensor, through the way of parametric calibration and linear interpolation to test and calculate the Forced Vital Capacity (FVC), Peak Expiratory Flow (PEF), Forced Expiratory Volume in one second (FEV1), and FEV1/FVC. Meanwhile, the detected parameters can be uploaded to the intelligent mobile terminal through the wireless transmission module. The device is able to show expiratory volume-time curve and the final parameters clearly, the error of measurement is less than 5%. In addition, that device is small and convenient, not only is good for clinical application, but also can be used for family in a house.
Forced Expiratory Volume ; Internet ; Respiratory Function Tests ; Spirometry ; Vital Capacity

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