Browsing by Author "Murayama, Sadayuki"
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- ItemCollapsibility of Lung Volume by Paired Inspiratiory and Expiratory CT Scans: Correlations with Lung Function and Mean Lung Density(ELSEVIER SCIENCE INC, 2010) Yamashiro, Tsuneo; Matsuoka, Shin; Bartholmai, Brian J.; Estepar, Raul San Jose; Ross, James C.; Diaz, Alejandro; Murayama, Sadayuki; Silverman, Edwin K.; Hatabu, Hiroto; Washko, George R.Rationale and Objectives: To evaluate the relationship between measurements of lung volume (LV) on inspiratory/expiratory computed tomography (CT) scans, pulmonary function tests (PFT), and CT measurements of emphysema in individuals with chronic obstructive pulmonary disease.
- ItemKurtosis and Skewness of Density Histograms on Inspiratory and Expiratory CT Scans in Smokers(INFORMA HEALTHCARE, 2011) Yamashiro, Tsuneo; Matsuoka, Shin; Estepar, Raul San Jose; Bartholmai, Brian J.; Diaz, Alejandro; Ross, James C.; Murayama, Sadayuki; Silverman, Edwin K.; Hatabu, Hiroto; Washko, George R.The aim of this study is to evaluate the relationship between lung function and kurtosis or skewness of lung density histograms on computed tomography (CT) in smokers. Forty-six smokers (age range 46-81 years), enrolled in the Lung Tissue Research Consortium, underwent pulmonary function tests (PFT) and chest CT at full inspiration and full expiration. On both inspiratory and expiratory scans, kurtosis and skewness of the density histograms were automatically measured by open-source software. Correlations between CT measurements and lung function were evaluated by the linear regression analysis. Although no significant correlations were found between inspiratory kurtosis or skewness and PFT results, expiratory kurtosis significantly correlated with the following: the percentage of predicted value of forced expiratory volume in the first second (FEV1), the ratio of FEV1 to forced vital capacity (FVC), and the ratio of residual volume (RV) to total lung capacity (TLC) (FEV1%predicted, R = -0.581, p < 0.001; FEV1/FVC, R = -0.612, p < 0.001; RV/TLC, R = 0.613, p < 0.001, respectively). Similarly, expiratory skewness showed significant correlations with PFT results (FEV1%predicted, R = -0.584, p < 0.001; FEV1/FVC, R = -0.619, p < 0.001; RV/TLC, R = 0.585, p < 0.001, respectively). Also, the expiratory/inspiratory (E/I) ratios of kurtosis and skewness significantly correlated with FEV1%predicted (p < 0.001), FEV1/FVC (p < 0.001), RV/TLC (p < 0.001), and the percentage of predicted value of diffusing capacity for carbon monoxide (kurtosis E/I ratio, p = 0.001; skewness E/I ratio, p = 0.03, respectively). We conclude therefore that expiratory values and the E/I ratios of kurtosis and skewness of CT densitometry reflect airflow limitation and air-trapping. Higher kurtosis or skewness on expiratory CT scan indicates more severe conditions in smokers.
- ItemQuantitative Airway Assessment on Computed Tomography in Patients with alpha(1)-antitrypsin Deficiency(TAYLOR & FRANCIS INC, 2009) Yamashiro, Tsuneo; Matsuoka, Shin; Estepar, Raul San Jose; Diaz, Alejandro; Newell, John D.; Sandhaus, Robert A.; Mergo, Patricia J.; Brantly, Mark L.; Murayama, Sadayuki; Reilly, John J.; Hatabu, Hiroto; Silverman, Edwin K.; Washko, George R.The relationship between quantitative airway measurements on computed tomography (CT) and airflow limitation in individuals with severe alpha(1)-antitrypsin deficiency (AATD) is undefined. Thus, we planned to clarity the relationship between CT-based airway indices and airflow limitation in AATD. 52 patients with AATD underwent chest CT and pre-bronchodilator spirometry at three institutions. In the right upper (RUL) and lower (RLL) lobes, wall area percent (WA%) and luminal area (Ai) were measured in the third, fourth, and fifth generations of the bronchi. The severity of emphysema was also calculated in each lobe and expressed as low attenuation area percent (LAA%). Correlations between obtained measurements and FEV1% predicted (FEV1%P) were evaluated by the Spearman rank correlation test. In RUL, WA% of all generations was significantly correlated with FEV1%P (3rd, R = -0.33, p = 0.02; 4th, R = -0.39, p = 0.004; 5th, R = -0.57, p < 0.001; respectively). Ai also showed significant correlations (3rd, R = 0.32, p = 0.02; 4th, R = 0.34, p = 0.01; 5th, R = 0.56, p < 0.001; respectively). Measured correlation coefficients improved when the airway progressed distally from the third to fifth generations. LAA% also correlated with FEV1%P (R = -0.51, p < 0.001). In RLL, WA% showed weak correlations with FEV1%P in all generations (3rd, R = -0.34, p = 0.01; 4th, R = -0.30, P = 0.03; 5th, R = -0.31, p = 0.03; respectively). Only Ai from the fifth generation significantly correlated with FEV1%P in this lobe (R = 0.34, p = 0.01). LAA% strongly correlated with FEV1%P (R = -0.71, p < 0.001). We conclude therefore that quantitative airway measurements are significantly correlated with airflow limitation in AATD, particularly in the distal air-ways of RUL. Emphysema of the lower lung is the predominant component; however, airway disease also has a significant impact on airflow limitation in AATD.
- ItemQuantitative Assessment of Bronchial Wall Attenuation With Thin-Section CT: An Indicator of Airflow Limitation in Chronic Obstructive Pulmonary Disease(AMER ROENTGEN RAY SOC, 2010) Yamashiro, Tsuneo; Matsuoka, Shin; Estepar, Raul San Jose; Dransfield, Mark T.; Diaz, Alejandro; Reilly, John J.; Patz, Samuel; Murayama, Sadayuki; Silverman, Edwin K.; Hatabu, Hiroto; Washko, George R.OBJECTIVE. The purpose of this study was to evaluate the relation between bronchial wall attenuation on thin-section CT images and airflow limitation in persons with chronic obstructive pulmonary disease. SUBJECTS AND