In the present study, computational fluid dynamics (CFD) is used to investigate inspiratory and expiratory airflow characteristics in the human upper respiratory tract for the purpose of identifying the probable loc...In the present study, computational fluid dynamics (CFD) is used to investigate inspiratory and expiratory airflow characteristics in the human upper respiratory tract for the purpose of identifying the probable locations of particle deposition and the wall injury. Computed tomography (CT) scan data was used to reconstruct a three dimensional respiratory tract from trachea to first generation bronchi. To compare, a simplified model of respiratory tract based on Weibel was also used in the study. The steady state results are obtained for an airflow rate of 45 L/min, corresponding to the heavy breathing condition. The velocity distribution, wall shear stress, static pressure and particle deposition are compared for inspiratory flows in simplified and realistic models and expiratory flows in realistic model only. The results show that the location of cartilaginous rings is susceptible to wall injury and local particle deposition.展开更多
18 F-fluorodeoxyglucose positron emission/computed tomography( 18 F-FDG PET/CT)imaging,an established procedure for evaluation of malignancy,shows an increased 18 F-FDG uptake in inflammatory conditions.We present thr...18 F-fluorodeoxyglucose positron emission/computed tomography( 18 F-FDG PET/CT)imaging,an established procedure for evaluation of malignancy,shows an increased 18 F-FDG uptake in inflammatory conditions.We present three patients with abdominal pain and weight loss.Conventional imaging studies indicated that abdominal neoplasm and 18 F-FDG PET/CT for assessment of malignancy showed multiple lesions with intense 18 FFDG uptake in abdomen of the three cases.However,the three patients were finally diagnosed wit...展开更多
基金funded by Department of Science & Technology Government of India through the DST-FIST grant
文摘In the present study, computational fluid dynamics (CFD) is used to investigate inspiratory and expiratory airflow characteristics in the human upper respiratory tract for the purpose of identifying the probable locations of particle deposition and the wall injury. Computed tomography (CT) scan data was used to reconstruct a three dimensional respiratory tract from trachea to first generation bronchi. To compare, a simplified model of respiratory tract based on Weibel was also used in the study. The steady state results are obtained for an airflow rate of 45 L/min, corresponding to the heavy breathing condition. The velocity distribution, wall shear stress, static pressure and particle deposition are compared for inspiratory flows in simplified and realistic models and expiratory flows in realistic model only. The results show that the location of cartilaginous rings is susceptible to wall injury and local particle deposition.
文摘18 F-fluorodeoxyglucose positron emission/computed tomography( 18 F-FDG PET/CT)imaging,an established procedure for evaluation of malignancy,shows an increased 18 F-FDG uptake in inflammatory conditions.We present three patients with abdominal pain and weight loss.Conventional imaging studies indicated that abdominal neoplasm and 18 F-FDG PET/CT for assessment of malignancy showed multiple lesions with intense 18 FFDG uptake in abdomen of the three cases.However,the three patients were finally diagnosed wit...