• Tuberculosis and Respiratory Diseases
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• v.57 no.6
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• pp.567-572
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• 2004

Background : The effect of PEEP(ed note: Define PEEP.) on the lung volume in patients with auto-PEEP during mechanical ventilation is not even. In patients with an expiratory limitation such as COPD, a PEEP of 85% from an auto-PEEP can be used with minimal increase in the lung volume. However, the application of PEEP to patients without an expiratory flow limitation can result in progressive lung. This study was carried out to evaluate the different PEEP effects on the lung volume according to the different pulmonary diseases. Methods : Sixteen patients who presented with auto-PEEP during mechanical ventilation were enrolled in this study. These patients were divided into 3 groups: asthma, COPD and tuberculosis sequela (patients with severe cicatrical fibrosis as a result of previous tuberculosis and compensatory emphysema). A PEEP of 25, 50, 75 and 100% of the auto-PEEP was applied, and the lung volume increments were estimated using the trapped lung volume. Results : In the asthma group, the trapped lung volume was not increased at a PEEP of 25 and 50% of the auto-PEEP. This group showed a significant lung volume increment from a 75% PEEP. In the COPD group, the lung volume was increased only at 100% PEEP. In the tuberculosis sequela group, the lung volume was increased progressively from low PEEP levels. However, a significant increment of the lung volume was noted only at 100% PEEP. Conclusion : The effects of the applied PEEP on the lung volume were different depending on the underlying lung pathology. The level of the applied PEEP >50% of the auto-PEEP might increase the trapped lung volume in patients with asthma.

• Journal of Veterinary Clinics
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• v.28 no.5
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• pp.510-515
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• 2011

This study was performed to quantitatively assess the normal lung volume and density according to the position by multi-detector computed tomography (MDCT) in dogs. Helical CT of the thorax was performed on 4 different positions with dorsal, left lateral, right lateral and ventral recumbency in 6 Pekingese and 6 Maltese dogs. During CT scanning, dogs were kept hyperventilated. Through the 3-dimensional reconstruction of CT images, the lung parameters were measured as the volume and density of the left, right including accessory lobe, and total lung. 3D images represented the different lung shape between Pekingese and Maltese dogs. Their difference of total lung volume and total lung density was not significant on the each position in both breeds. Right lung volume was significantly higher than left. The difference of left and right volume was $66.91{\pm}25.1$ ml. Linear relationship was shown between body weight and lung volume of ventral recumbency position. The dependent lung had higher density and lower volume than nondependent lung in both breed dogs. The volume of nondependent lung was not changed compared with the volume on ventral or dorsal recumbency. The total lung volume measured with MDCT is correlated with the lung density, and the lung density is useful to predict the normal total lung volume.

• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.767-773
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• 2023

To In this study, we sought to evaluate related factors affecting lung volume and their significance in pulmonary function and ventilation disorders. As experimental subjects, 206 normal adult men and women who underwent a low-dose chest CT scan and a spirometry test were selected at the same time. The experimental method was to measure lung volume using lung CT images obtained through a low-dose chest CT scan using deep learning-based AVIEW. Measurements were made using the LCS automatic diagnosis program. In addition, the results of measuring lung function were obtained using a spirometer, and gender and BMI were selected as related factors that affect lung volume, and significance was evaluated through an independent sample T-test with lung volume. As a result of the experiment, it was confirmed that in evaluating lung volume according to gender, all lung volumes of men were larger than all lung volumes of women. he result of an independent samples T-test using the respective average values for gender and lung volume showed that all lung volumes were larger in men than in women, which was significant (p<0.001). And in the evaluation of lung volume according to BMI index, it was confirmed that all lung volumes of adults with a BMI index of 24 or higher were larger than all lung volumes of adults with a BMI index of less than 24. However, the independent samples T-test using the respective average values for BMI index and lung volume did not show a significant result that all lung volumes were larger in BMI index 24 or higher than in BMI index less than 24 (p<0.055). In the evaluation of lung volume according to the presence or absence of pulmonary ventilation impairment, it was confirmed that all lung volumes of adults with normal pulmonary function ventilation were larger than all lung volumes of adults with pulmonary ventilation impairment. And as a result of the independent sample T-test using the respective average values for the presence or absence of pulmonary ventilation disorder and lung volume, the result was significant that all lung volumes were larger in adults with normal pulmonary function ventilation than in adults with pulmonary function ventilation disorder (p <0.001). Lung volume and spirometry test results are the most important indicators in evaluating lung health, and using these two indicators together to evaluate lung function is the most accurate evaluation method. Therefore, it is expected that this study will be used as basic data by presenting the average lung volume for adults with normal ventilation and adults with impaired lung function and ventilation in similar future studies on lung volume and vital capacity testing.

• Journal of Biomedical Engineering Research
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• v.11 no.2
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• pp.195-202
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• 1990

The hypothesis of asymmetric resistance to explain the phenomenon of lung hyperinflation (LHI) during hlgh frequency ventilation (HFV) was quantitatively studied. LHI was predicted by modeling the ism-volume pressure-flow (IVPF) data from 5 human subjects using the empirical Rohrer's equation. Non-steadiness during HFV was compensated by em- ploying recently proposed volume-frequency diagram. Tidal volume and ventilation frequency were 100 ml and 20 Hz, respectively. Airflow pattern was a symmetric sinusoid. The predic- tion results of mean pressure drop across the airways were averaged for those 5 subjects, and compared with zero by one-sided student's t-test. A marginally significant (P<0.1) increase in mean pressure drop was observed during HFV at low lung volumes (below FRC) , which could increase mean lung volume up to one liter When the lung volume was above FRC, no significant LHI (P >0.25) was resulted. LHI seemed to be inversely related to the lung volume. These results recommend to clinically apply HFV only at lung volumes above FRC.

• Tuberculosis and Respiratory Diseases
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• v.83 no.1
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• pp.61-70
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• 2020

Background: Circulating tumor cells (CTCs) are frequently detected in patients with advanced-stage malignant tumors and could act as a predictor of poor prognosis. However, there is a paucity of data on the relationship between CTC number and primary tumor volume in patients with lung cancer. Therefore, our study aimed to evaluate the relationship between CTC number and primary tumor volume in patients with lung adenocarcinoma. Methods: We collected blood samples from 21 patients with treatment-naive lung adenocarcinoma and 73 healthy individuals. To count CTCs, we used a CTC enrichment method based on fluid-assisted separation technology. We compared CTC numbers between lung adenocarcinoma patients and healthy individuals using propensity score matching, and performed linear regression analysis to analyze the relationship between CTC number and primary tumor volume in lung adenocarcinoma patients. Results: CTC positivity was significantly more common in lung adenocarcinoma patients than in healthy individuals (p<0.001). The median primary tumor volume in CTC-negative and CTC-positive patients was 10.0 ㎤ and 64.8 ㎤, respectively. Multiple linear regression analysis showed that the number of CTCs correlated with primary tumor volume in lung adenocarcinoma patients (β=0.903, p=0.002). Further subgroup analysis showed a correlation between CTC number and primary tumor volume in patients with distant (p=0.024) and extra-thoracic (p=0.033) metastasis (not in patients with distant metastasis). Conclusion: Our study showed that CTC numbers may be associated with primary tumor volume in lung adenocarcinomas patients, especially in those with distant metastasis.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.551-560
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• 2003

Particle deposition in human lungs was investigated theoretically by using asymmetric five-lobe lung model. The volumes of each of the five lobes were different, thereby forming an asymmetric lung structure. The tidal volume and flow rate of each lobe were scaled according to lobar volume. The total and regional deposition with various breathing patterns were calculated by means of tracking volume segments and accounting for particle loss during inhalation and exhalation. The deposition fractions were obtained for each airway generation and lung lobe, and dominant deposition mechanisms were investigated for different size particles. Results show that the tidal volume and flow rate have a characteristic influence on particle deposition. The total deposition fraction increases with an increase in tidal volume for all particle sizes. However, flow rate has dichotomous effects: a higher flow rate results in a sharp increase in deposition for large size particles, but decreases deposition for small size particles. Deposition distribution within the lung shifts proximally with higher flow rate whereas deposition peak shifts to the deeper lung region with larger tidal volume. Deposition fraction in each lobe was proportional to its volume. Among the three main deposition mechanisms, diffusion was dominant for particles < 0.5 ${\mu}{\textrm}{m}$ whereas sedimentation and impaction were most influential for larger size particles. Impaction was particularly dominant for particles> 8 ${\mu}{\textrm}{m}$. The results may prove to be useful for estimating deposition dose of inhaled pollutant particles at various breathing conditions.

• Journal of the Korean Society of Radiology
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• v.82 no.6
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• pp.1534-1544
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• 2021

Purpose To examine the effect of lung volume on the size and volume of pulmonary subsolid nodules (SSNs) measured on CT. Materials and Methods A total of 42 SSNs from 31 patients were included. CT examination was first performed at total lung capacity (TLC), and a section containing the nodule was additionally scanned at tidal volume (TV). The diameter and volume of each SSN, as well as the cross-sectional lung area containing the nodule, were measured. The significance of the changes in measurements between TLC and TV within the same individuals was evaluated. Results The lung area and the diameter and volume of SSNs decreased significantly at TV by 12.7 cm², 0.5 mm, and 46.4 mm³ on average, respectively (p < 0.001), compared to those at TLC. Changes in lung area between TV and TLC were positively correlated with the change in SSN diameter (p = 0.027) and volume (p = 0.014). However, after correction (by considering the change in lung area), the changes in SSN diameter (p = 0.124) and volume (p = 0.062) were not significantly different. Conclusion SSN size and volume can be significantly affected by lung volume during CT scans of the same individuals.

• Journal of Korean Critical Care Nursing
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• v.2 no.1
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• pp.15-25
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• 2009

Purpose: This study investigated the effects of chest physiotherapies on intensive care unit patients mechanical ventilated. Methods: Good lung down position, chest percussion, postural drainage was applied to patients who admitted to ICU. Each patients divided into four groups and each group received different treatments. Sputum amount, lung compliance, tidal volume and oxygen saturation were measured before treatment and immediately, and time flowing. Data was analyzed with frequency, percentage, ANOVA and paired t-test using via SPSSWIN 12.0 program. Results: There were significant differences in variables each characteristics of subjects. Chest percussion increased tidal volume, static lung compliance for the mean time. Desaturation related to suction. Conclusion: Chest percussion influences on lung compliance. Based on this study results and limitation, this study suggests repeated studies in various groups

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3816-3823
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• 2022

This work analyzed the dosimetric difference between the intensity modulated radiotherapy (IMRT), partial/single/double-arc volumetric modulated arc therapy (PA/SA/DA-VMAT) techniques in treatment planning for treating more than one target of lung cancer at different isocenters. IMRT and VMAT plans at different isocenters were created systematically using a Harold heterogeneous lung phantom. The conformity index (CI), homogeneity index (HI), gradient index (GI), dose-volume histogram and mean and maximum dose of the PTV were calculated and analyzed. Furthermore, the dose-volume histogram and mean and maximum doses of the OARs such as right lung, contralateral lung and non GTV were determined from the plans. The IMRT plans showed the superior target dose coverage, higher mean and maximum values than other VMAT techniques. PA-VMAT technique shows more lung sparing and DA-VMAT increases the V_5/10/20 values of contralateral lung than other VMAT and IMRT techniques. The IMRT technique achieves highly conformal dose distribution to the target than other VMAT techniques. Comparing to the IMRT plans, the higher V_5/10/20 and mean lung dose were observed in the contralateral lung in the DA-VMAT.

• Radiation Oncology Journal
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• v.15 no.2
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• pp.137-143
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• 1997

Purpose : Radiation pneumonitis is one of the complications caused by radiation therapy that includes a Portion of the lung tissue. The severity of radiation induced pulmonary dysfunction depends on the irradiated lung volume, total dose, dose rate and underlying Pulmonary function. It also depends on whether chemotherapy is done or not. The irradiated lung volume is the most important factor to predict the pulmonary dysfunction in breast cancer Patients following radiation therapy. There are some data that show the irradiated lung volume measured from CT scans as a part of treatment Planning with the tangential beams. But such data have not been reported in Korea. We planned to evaluate the irradiated lung volume quantitatively using CT scans for the breast tangential field and search for useful factors that could Predict the irradiated lung volume Materials and Methods : The lung volume was measured for 25 patients with breast cancer irradiated with tangential field from Jan.1995 to Aug.1996. Parameters that can predict the irradiated lung volume included; (1) the peruendicular distance from the Posterior tangential edge to the posterior part of the anterior chest wall at the center of the field (CLD) ; (2) the maximum perpendicular distance from the posterior tangential field edge to the posterior Part of the anterior chest wall (MLD) ; (3) the greatest perpendicular distance from the Posterior tangential edge to the posterior part of anterior chest wall on CT image at the center of the longitudinal field (GPD) ; (4) the length of the longitudinal field (L). The irradiated lung volume(RV), the entire both lung volume(EV) and the ipsilateral lung volume(IV) were measured using dose volume histogram. The relationship between the irradiated lung volume and predictors was evaluated by regression analysis. Results :The RV is 61-279cc (mean 170cc), the RV/EV is $2.9-13.0\%\;(mean\;5.8\%)$ and the RV/IV is $4.9-29.0\%\;(mean\;12.2\%)$. The CLD, the MLD and the GPD ave 1.9-3.3cm, 1.9-3.3cm and 1.4-3.1cm respectively. The significant relations between the irradiated lung volume such as RV. RV/EV, RV/IV and parameters such as CLD, MLD, GPO, L. $CLD\timesL,\;MLD\timesL\;and\;GPD\timesL$ are not found with little variances in parameters. The RV/IV of the left breast irradiation is significantly larger than that of the right but the RV/EVS do not show the differences. There is no symptomatic radiation pneumonitis at least during 6 months follow up. Conclusion : The significant relationship between the irradiated lung volume and predictors is not found with little variation on parameters. The irradiated lung volume in the tangential held is liss than $10\%$ of entire lung volume when CLO is less than 3cm. The RV/IV of the left tangential field is larger than that of the right but there was no significant differences in RV/EVS. Symptomatic radiation pneumonitis has not occurred during minimum 6 months follow up.