title: Patients with emphysema: quantitative CT analysis before and after lung volume reduction surgery. Work in progress.
abstract: OBJECTIVE
  To quantitatively assess the morphologic changes in the lungs after lung volume reduction surgery and determine whether changes at quantitative computed tomography (CT) reflect changes in lung function.
  
  
  METHODS
  In 10 patients, chest CT images were obtained at full inspiration and expiration before and after surgery. A semiautomated segmentation method was developed to isolate the lung regions and calculate the lung volumes and frequency distribution of attenuation values. The changes in lung volume and attenuation after surgery were compared with clinical findings, and an exploratory evaluation of outcome predictors was conducted.
  
  
  RESULTS
  Semiautomated segmentation and quantitative analysis compared favorably with manual techniques, and there was good correlation between the emphysema indexes and percentage predicted forced expiratory volume in 1 second, forced expiratory volume in 1 second/forced vital capacity, and diffusing capacity. The emphysema index decreased from 60% to 38% at inspiration and from 60% to 27% at expiration after surgery. The average CT lung volume decreased from 7.5 to 5.6 L at inspiration (25%) and from 6.4 to 3.8 L (41%) at expiration after surgery and correlated well with measurements at plethysmography.
  
  
  CONCLUSIONS
  Substantial decreases in the lung volumes and emphysema index, increased airflow, possible reexpansion of some remaining lung, and the relation between preoperative quantitative CT indexes and clinical outcome suggest a multifactorial mechanism for improvement seen after surgery.
authors.affiliation: Mallinckrodt Institute of Radiology, Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA.
authors.forename: K T
authors.initials: KT
authors.lastname: Bae
authors.forename: R M
authors.initials: RM
authors.lastname: Slone
authors.forename: D S
authors.initials: DS
authors.lastname: Gierada
authors.forename: R D
authors.initials: RD
authors.lastname: Yusen
authors.forename: J D
authors.initials: JD
authors.lastname: Cooper
mesh_terms: D000328:Adult; D000368:Aged; D005069:Evaluation Studies as Topic; D005260:Female; D005541:Forced Expiratory Volume; D005544:Forecasting; D006801:Humans; D007091:Image Processing, Computer-Assisted; D001239:Inhalation; D008168:Lung / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D011013:Pneumonectomy; D011182:Postoperative Care; D011300:Preoperative Care; D011653:Pulmonary Diffusing Capacity; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D012123:Pulmonary Ventilation; D012115:Residual Volume; D012119:Respiration; D014057:Tomography, X-Ray Computed; D014109:Total Lung Capacity; D016896:Treatment Outcome; D014797:Vital Capacity