Browsing by Author "Ross, James C."

Now showing 1 - 4 of 4
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    Airway Count and Emphysema Assessed by Chest CT Imaging Predicts Clinical Outcome in Smokers
    (ELSEVIER, 2010) Diaz, Alejandro A.; Valim, Clarissa; Yamashiro, Tsuneo; San Jose Estepar, Raul; Ross, James C.; Matsuoka, Shin; Bartholmai, Brian; Hatabu, Hiroto; Silverman, Edwin K.; Washko, George R.
    Background: Recently, it has been shown that emphysematous destruction of the lung is associated with a decrease in the total number of terminal bronchioles. It is unknown whether a similar decrease is visible in the more proximal airways. We aimed to assess the relationships between proximal airway count, CT imaging measures of emphysema, and clinical prognostic factors in smokers, and to determine whether airway count predicts the BMI, airflow obstruction, dyspnea, and exercise capacity (BODE) index.
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    Collapsibility 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.
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    Kurtosis 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.
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    Pulmonary lobe segmentation based on ridge surface sampling and shape model fitting
    (2013) Ross, James C.; Kindlmann, Gordon L.; Okajima, Yuka; Hiroto Hatabu, Díaz Fuenzalida, Alejandro; Silverman, Edwin K.; Washko, George R.; Dy, Jennifer; San José Estépar, Raúl