title: Clinical Significance of Forced Oscillation Technique for Evaluation of Small Airway Disease in Interstitial Lung Diseases.
abstract: Small airway disease (SAWD) in patients with interstitial lung disease (ILD) is often assessed by high-resolution computed tomography (HRCT). However, frequent HRCT examinations result in a high level of radiographic exposure. This study investigated the utility of the forced oscillation technique (FOT) to evaluate SAWD in patients with ILD.
  
  
  
  Broadband FOT using a commercially available device (MostGraph-01) and pulmonary function tests (PFT) were performed in 90 patients with ILD. HRCT images taken within 3 months were reviewed. The patients were divided into two groups according to the presence or absence of SAWD findings detected by HRCT. Clinical characteristics, PFT, and FOT between the two groups were compared.
  
  
  
  Of the 90 patients with ILD, 19 were classified as having SAWD findings (the presence group) and 71 as not having SAWD findings (the absence group). There were no significant differences in parameters of PFT between the two groups. The presence group had higher absolute values of reactance at 5 Hz (X5), resonant frequency (Fres), and low-frequency reactance area (ALX) than did the absence group. A within-breath change analysis demonstrated that the change in X5, Fres, and ALX between expiration and inspiration (ΔX5, ΔFres, ΔALX, respectively) was significantly different between the groups. A univariate analysis revealed that X5, Fres, ALX, ΔX5, ΔFres, ΔALX were significantly associated with the presence of SAWD findings. Multivariate analysis validated that Fres was related to the presence of SAWD findings.
  
  
  
  The FOT may be useful in detecting and evaluating SAWD in patients with ILD.
  
  
  
  UMIN 000020733.
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Mikamo
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan. fujisawa@hama-med.ac.jp.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Fujisawa
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Oyama
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Kono
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Enomoto
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: Department of Clinical Pharmacology and Therapeutics, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Inui
authors.affiliation: Department of Diagnostic Radiology, Osaka Rosai Hospital, 1179-3 Nagasone-cho, Kita-ku, Sakai, 591-8025, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Sumikawa
authors.affiliation: Department of Radiology, Kinki Central Hospital of Mutual Aid Association of Public School Teachers, 3-1 Kurumaduka, Itami, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Johkoh
authors.affiliation: Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Suda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000403:Airway Resistance; D019540:Area Under Curve; D045853:Exhalation; D005260:Female; D006801:Humans; D001239:Inhalation; D007770:L-Lactate Dehydrogenase / Q000097:blood; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000097:blood; D011237:Predictive Value of Tests; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood; D012372:ROC Curve; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: C060192:MUC1 protein, human; D018396:Mucin-1; D037663:Pulmonary Surfactant-Associated Protein D; D007770:L-Lactate Dehydrogenase
keywords: Forced oscillation technique; Interstitial lung disease; Reactance; Small airway disease