title: Low-density areas on high-resolution computed tomograms in chronic pediatric asthma.
abstract: OBJECTIVE
  In children with chronic persistent asthma, we evaluated whether the presence of increased residual volume (RV) after anti-inflammatory treatment correlates with the detection of low-density areas on high-resolution computed tomography (HRCT), similar to those in emphysema.
  
  
  METHODS
  Children with a confirmed diagnosis of asthma (n = 32) were enrolled in a prospective study. All patients had reduction of airflow in the peripheral airways, increased RV, and increased serum eosinophil cationic protein (ECP) values indicating airway inflammation. All the children were treated with salmeterol (50 microg twice daily) and fluticasone (250 microg twice daily) for a 3-month period.
  
  
  RESULTS
  At the end of treatment, peripheral eosinophil counts, serum ECP, forced expiratory volume in 1 second (FEV(1)), mean forced expiratory flow during the middle half of forced vital capacity (FEF(25-75)), RV, and total lung capacity values improved in all the patients. HRCT was normal in 22 children (68.8%); in the remaining 10 subjects, low-density areas were found despite normalization of FEV(1), FEF(25-75), and significant reduction in ECP. A significant correlation was found between persistence of RV values >150% predicted and the presence of low-density areas on HRCT (r = 0.84, P <.0001).
  
  
  CONCLUSIONS
  Structural changes similar to emphysema are also present in asthmatic children. Our findings suggest that the persistence of increased RV may be used to identify subjects with low-density areas on HRCT.
authors.affiliation: Department of Pediatrics, University of Pisa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Pifferi
authors.forename: Davide
authors.initials: D
authors.lastname: Caramella
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Ragazzo
authors.forename: Angelo
authors.initials: A
authors.lastname: Pietrobelli
authors.forename: Attilio L
authors.initials: AL
authors.lastname: Boner
mesh_terms: D000293:Adolescent; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D001249:Asthma / Q000000981:diagnostic imaging* / Q000188:drug therapy; D002648:Child; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D011446:Prospective Studies; D012115:Residual Volume / Q000187:drug effects; D015656:Respiratory Mechanics / Q000187:drug effects; D018709:Statistics, Nonparametric; D013256:Steroids; D014057:Tomography, X-Ray Computed
chemical_list: D000893:Anti-Inflammatory Agents; D013256:Steroids