title: Chronic tuberculous empyema: relationships between preoperative CT findings and postoperative improvement measured by pulmonary function testing.
abstract: OBJECTIVE
  To evaluate whether preoperative computed tomography (CT) findings correlate with postoperative improvements in forced vital capacity (FVC) and forced expiratory volume during 1s (FEV1) in persons who have undergone unilateral decortication because of unilateral chronic tuberculous empyema.
  
  
  METHODS
  A retrospective study was carried out of 67 individuals who had undergone decortication because of chronic tuberculous empyema between January 1996 and December 2000. Of these, 13 subjects who had had preoperative chest CT and preoperative and postoperative pulmonary function tests (PFTs) were included in the investigation. On preoperative CT, the degree of volume reduction of the affected side was compared with that of the contralateral normal lung. The relative volume of empyema was calculated by dividing the volume occupied by the empyema by the sum of the total volume of the ipsilateral lung and the empyema volume. The thicknesses of pleura and extrapleural fat in the involved hemithorax were measured by CT at their thickest points, and the degree of atelectasis adjacent to the empyema in the diseased lung was assessed and classified. These five CT parameters and the ages of the patients were compared with preoperative and postoperative FVC and FEV1 changes.
  
  
  RESULTS
  A significant negative correlation was found between FVC changes and the relative volume of the affected lung (FVC: p = 0.039, RS = -0.58). FVC and FEV1 were found to be significantly and positively correlated with the relative volume of the empyema (FVC: p = 0.005, RS = 0.72; FEV1: p = 0.014, RS = 0.66) and the degree of atelectasis (FVC: p = 0.007, RS = 0.71; FEV1: p = 0.029, RS = 0.60) by Spearman's nonparametric correlation test. Other CT parameters and the ages of the patients were not found to be correlated with PFT changes.
  
  
  CONCLUSIONS
  The relative volume of the affected side, the relative volume of empyema and the degree of atelectasis can predict improvements in FVC and FEV1 after decortication in patients with chronic tuberculous empyema.
authors.affiliation: Department of Radiology, Seoul National University Collage of Medicine and the Institute of Radiation Medicine, SNUMRC, 28, Yongon-dong, Chongno-gu, Seoul 110-744, South Korea.
authors.forename: D J
authors.initials: DJ
authors.lastname: Kim
authors.forename: J-G
authors.initials: JG
authors.lastname: Im
authors.forename: J M
authors.initials: JM
authors.lastname: Goo
authors.forename: H J
authors.initials: HJ
authors.lastname: Lee
authors.forename: S Y
authors.initials: SY
authors.lastname: You
authors.forename: J W
authors.initials: JW
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D004654:Empyema, Tuberculous / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011300:Preoperative Care / Q000379:methods; D001261:Pulmonary Atelectasis / Q000000981:diagnostic imaging / Q000209:etiology; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D014797:Vital Capacity