OBJECTIVE: To evaluate the technical feasibility, performance, and interobserver agreement of a computer-aided classification (CAC) system for regional ventilation at two-phase xenon-enhanced CT in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Thirty-eight patients with COPD underwent two-phase xenon ventilation CT with resulting wash-in (WI) and wash-out (WO) xenon images. The regional ventilation in structural abnormalities was visually categorized into four patterns by consensus of two experienced radiologists who compared the xenon attenuation of structural abnormalities with that of adjacent normal parenchyma in the WI and WO images, and it served as the reference. Two series of image datasets of structural abnormalities were randomly extracted for optimization and validation. The proportion of agreement on a per-lesion basis and receiver operating characteristics on a per-pixel basis between CAC and reference were analyzed for optimization. Thereafter, six readers independently categorized the regional ventilation in structural abnormalities in the validation set without and with a CAC map. Interobserver agreement was also compared between assessments without and with CAC maps using multirater kappa statistics. RESULTS: Computer-aided classification maps were successfully generated in 31 patients (81.5%). The proportion of agreement and the average area under the curve of optimized CAC maps were 94% (75/80) and 0.994, respectively. Multirater kappa value was improved from moderate (kappa = 0.59; 95% confidence interval [CI], 0.56-0.62) at the initial assessment to excellent (kappa = 0.82; 95% CI, 0.79-0.85) with the CAC map. CONCLUSION: Our proposed CAC system demonstrated the potential for regional ventilation pattern analysis and enhanced interobserver agreement on visual classification of regional ventilation.
Aged ; Area Under Curve ; Feasibility Studies ; Female ; Humans ; Male ; Middle Aged ; Observer Variation ; Pulmonary Disease, Chronic Obstructive/physiopathology/*radiography ; Pulmonary Emphysema/physiopathology/radiography ; *Respiration ; Retrospective Studies ; Tomography, X-Ray Computed/*methods ; Xenon/*diagnostic use

OBJECTIVE: We wanted to assess the relationship between measurements of the right ventricular (RV) function and mass, with using cardiac multi-detector computed tomography (MDCT) and the severity of chronic obstructive pulmonary disease (COPD) as determined by the pulmonary function test (PFT). MATERIALS AND METHODS: Measurements of PFT and cardiac MDCT were obtained in 33 COPD patients. Using the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification, the patients were divided into three groups according to the severity of the disease: stage I (mild, n = 4), stage II (moderate, n = 15) and stage III (severe, n = 14). The RV function and the wall mass were obtained by cardiac MDCT. The results were compared among the groups using the Student-Newman-Keuls method. Pearson's correlation was used to evaluate the relationship between the right ventricular ejection fraction (RVEF) and the wall mass results with the PFT results. P-values less than 0.05 were considered statistically significant. RESULTS: The RVEF and mass were 47+/-3% and 41+/-2 g in stage I, 46+/-6% and 46+/-5 g in stage II, and 35+/-5% and 55+/-6 g in stage III, respectively. The RVEF was significantly lower in stage III than in stage I and II (p < 0.01). The RV mass was significantly different among the three stages, according to the disease severity of COPD (p < 0.05). The correlation was excellent between the MDCT results and forced expiratory volume in 1 sec (r = 0.797 for RVEF and r = -0.769 for RV mass) and forced expiratory volume in 1 sec to the forced vital capacity (r = 0.745 for RVEF and r = -0.718 for RV mass). CONCLUSION: Our study shows that the mean RV wall mass as measured by cardiac MDCT correlates well with the COPD disease severity as determined by PFT.
Ventricular Dysfunction, Right/*etiology/physiopathology/*radiography ; Tomography, X-Ray Computed/*methods ; Statistics, Nonparametric ; Respiratory Function Tests ; Pulmonary Disease, Chronic Obstructive/*complications/physiopathology ; Middle Aged ; Male ; Humans ; Female ; Analysis of Variance ; Aged

BACKGROUND/AIMS: Many studies have investigated angina and its relationship with chronic obstructive pulmonary disease (COPD). However, angina was diagnosed only by noninvasive tests or only by clinical symptoms in most of these studies. The aim of this study was to compare the prognosis, including rate of hospitalization and death from significant coronary artery lesion and nonsignificant coronary artery lesion angina, in patients with COPD. METHODS: Patients with COPD who underwent coronary angiography (CAG) due to angina were reviewed retrospectively at a tertiary referral hospital. COPD is defined as post-bronchodilator forced expiratory volume in 1 sec/forced vital capacity (FEV1/FVC) of < 70%. A significant coronary lesion is defined as at least 50% diameter stenosis of one major epicardial artery in CAG. RESULTS: In total, 113 patients were enrolled. Mean follow-up duration was 39 +/- 21 months. Of the patients, 52 (46%) had mild COPD and 48 (42%) had moderate COPD. Sixty-nine (61%) patients had significant stenosis in CAG. The death rate in the follow-up period was 2.21 per 100 patient-years. No significant difference was observed among the all-cause mortality rate, admission rate, or intensive care unit admission rate in patients who had COPD with or without significant coronary artery disease. Pneumonia or acute exacerbation of COPD was the most common cause of admission. CONCLUSIONS: In patients having COPD with angina who underwent CAG, no significant difference was observed in mortality or admission events depending on the presence of a significant coronary artery lesion during the 2-year follow-up period.
Aged ; Angina Pectoris/*etiology ; Chi-Square Distribution ; Coronary Angiography ; Coronary Stenosis/*complications/mortality/radiography ; Female ; Forced Expiratory Volume ; Hospitalization ; Humans ; Kaplan-Meier Estimate ; Lung/physiopathology ; Male ; Middle Aged ; Prognosis ; Pulmonary Disease, Chronic Obstructive/*complications/diagnosis/mortality/physiopathology ; Republic of Korea ; Retrospective Studies ; Risk Assessment ; Risk Factors ; Severity of Illness Index ; Spirometry ; Time Factors ; Vital Capacity