title: Pulmonary disease in cystic fibrosis: assessment with chest CT at chest radiography dose levels.
abstract: OBJECTIVE
  To investigate a computed tomographic (CT) protocol with iterative reconstruction at conventional radiography dose levels for the assessment of structural lung abnormalities in patients with cystic fibrosis ( CF cystic fibrosis ).
  
  
  METHODS
  In this institutional review board-approved study, 38 patients with CF cystic fibrosis (age range, 6-58 years; 21 patients <18 years and 17 patients >18 years) underwent investigative CT (at minimal exposure settings combined with iterative reconstruction) as a replacement of yearly follow-up posteroanterior chest radiography. Verbal informed consent was obtained from all patients or their parents. CT images were randomized and rated independently by two radiologists with use of the Bhalla scoring system. In addition, mosaic perfusion was evaluated. As reference, the previous available conventional chest CT scan was used. Differences in Bhalla scores were assessed with the χ(2) test and intraclass correlation coefficients ( ICC intraclass correlation coefficient s). Radiation doses for CT and radiography were assessed for adults (>18 years) and children (<18 years) separately by using technical dose descriptors and estimated effective dose. Differences in dose were assessed with the Mann-Whitney U test.
  
  
  RESULTS
  The median effective dose for the investigative protocol was 0.04 mSv (95% confidence interval [ CI confidence interval ]: 0.034 mSv, 0.10 mSv) for children and 0.05 mSv (95% CI confidence interval : 0.04 mSv, 0.08 mSv) for adults. These doses were much lower than those with conventional CT (median: 0.52 mSv [95% CI confidence interval : 0.31 mSv, 3.90 mSv] for children and 1.12 mSv [95% CI confidence interval : 0.57 mSv, 3.15 mSv] for adults) and of the same order of magnitude as those for conventional radiography (median: 0.012 mSv [95% CI confidence interval : 0.006 mSv, 0.022 mSv] for children and 0.012 mSv [95% CI confidence interval : 0.005 mSv, 0.031 mSv] for adults). All images were rated at least as diagnostically acceptable. Very good agreement was found in overall Bhalla score ( ICC intraclass correlation coefficient , 0.96) with regard to the severity of bronchiectasis ( ICC intraclass correlation coefficient , 0.87) and sacculations and abscesses ( ICC intraclass correlation coefficient , 0.84). Interobserver agreement was excellent ( ICC intraclass correlation coefficient , 0.86-1).
  
  
  CONCLUSIONS
  For patients with CF cystic fibrosis , a dedicated chest CT protocol can replace the two yearly follow-up chest radiographic examinations without major dose penalty and with similar diagnostic quality compared with conventional CT.
authors: From the Department of Radiology (C.W.E., I.A.B., B.I., N.B., G.V.G., K.H.N., F.V., M.D.M., J.d.M.), Department of Medical Imaging and Physical Sciences (N.B.), Department of Pediatric Pneumology (E.D.W., A.M.), Cystic Fibrosis Clinic (A.M.), Department of Medicine (D.C., J.D.M.), and Department of Biomedical Statistics and Informatics (D.C.), Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium.
authors: Caroline W
authors: CW
authors: Ernst
authors: Ines A
authors: IA
authors: Basten
authors: Bart
authors: B
authors: Ilsen
authors: Nico
authors: N
authors: Buls
authors: Gert
authors: G
authors: Van Gompel
authors: Elke
authors: E
authors: De Wachter
authors: Koenraad H
authors: KH
authors: Nieboer
authors: Filip
authors: F
authors: Verhelle
authors: Anne
authors: A
authors: Malfroot
authors: Danny
authors: D
authors: Coomans
authors: Michel
authors: M
authors: De Maeseneer
authors: Johan
authors: J
authors: de Mey
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003550:Cystic Fibrosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D013902:Radiography, Thoracic; D014057:Tomography, X-Ray Computed / Q000379:methods*