title: Clinical correlates of lung ventilation defects in asthmatic children.
abstract: BACKGROUND
  Lung ventilation defects identified by using hyperpolarized 3-helium gas ((3)He) lung magnetic resonance imaging (MRI) are prevalent in asthmatic patients, but the clinical importance of ventilation defects is poorly understood.
  
  
  OBJECTIVE
  We sought to correlate the lung defect volume quantified by using (3)He MRI with clinical features in children with mild and severe asthma.
  
  
  METHODS
  Thirty-one children with asthma (median age, 10 years; age range, 3-17 years) underwent detailed characterization and (3)He lung MRI. Quantification of the (3)He signal defined ventilation defect and hypoventilated, ventilated, and well-ventilated volumes.
  
  
  RESULTS
  The ventilation defect to total lung volume fraction ranged from 0.1% to 11.6%. Children with ventilation defect percentages in the upper tercile were more likely to have severe asthma than children in the lower terciles (P = .005). The ventilation defect percentage correlated (P < .05 for all) positively with the inhaled corticosteroid dose, total number of controller medications, and total blood eosinophil counts and negatively with the Asthma Control Test score, FEV1 (percent predicted), FEV1/forced vital capacity ratio (percent predicted), and forced expiratory flow rate from 25% to 75% of expired volume (percent predicted).
  
  
  CONCLUSIONS
  The lung defect volume percentage measured by using (3)He MRI correlates with several clinical features of asthma, including severity, symptom score, medication requirement, airway physiology, and atopic markers.
authors.affiliation: Department of Radiology, University of Missouri School of Medicine, Columbia, Mo.
authors.forename: Talissa A
authors.initials: TA
authors.lastname: Altes
authors.affiliation: Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va; Department of Biomedical Engineering, University of Virginia, Charlottesville, Va.
authors.forename: John P
authors.initials: JP
authors.lastname: Mugler
authors.affiliation: Center for Pulmonary Imaging Research, Cincinnati Children's Hospital, Cincinnati, Ohio.
authors.forename: Kai
authors.initials: K
authors.lastname: Ruppert
authors.affiliation: Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Tustison
authors.affiliation: Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va.
authors.forename: Joanne
authors.initials: J
authors.lastname: Gersbach
authors.affiliation: Child Health Research Center, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Szentpetery
authors.affiliation: Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va; Department of Biomedical Engineering, University of Virginia, Charlottesville, Va.
authors.forename: Craig H
authors.initials: CH
authors.lastname: Meyer
authors.affiliation: Division of Medical Imaging Research, Department of Radiology and Medical Imaging, University of Virginia School of Medicine, Charlottesville, Va.
authors.forename: Eduard E
authors.initials: EE
authors.lastname: de Lange
authors.affiliation: Child Health Research Center, Department of Pediatrics, University of Virginia School of Medicine, Charlottesville, Va. Electronic address: wgt2p@virginia.edu.
authors.forename: W Gerald
authors.initials: WG
authors.lastname: Teague
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005541:Forced Expiratory Volume; D006371:Helium; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D007554:Isotopes; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D012123:Pulmonary Ventilation; D012307:Risk Factors; D012720:Severity of Illness Index; D014797:Vital Capacity
chemical_list: D007554:Isotopes; D006371:Helium; D007073:Immunoglobulin E
keywords: (3)He magnetic resonance imaging; Hyperpolarized; childhood asthma; severe asthma; ventilation defects; ventilation heterogeneity