title: Screening for interstitial lung disease in systemic sclerosis: performance of high-resolution CT with limited number of slices: a prospective study.
abstract: OBJECTIVE
  Early diagnosis of interstitial lung disease (ILD), currently the main cause of death in systemic sclerosis (SSc), is needed. The gold standard is high-resolution CT (HRCT) of the chest, but regular screening faces the risk of increased radiation exposure. We performed a prospective validation of a dedicated, 9-slice HRCT protocol with reduced radiation dose for the detection of ILD in patients with SSc.
  
  
  METHODS
  We analysed 170/205 consecutive patients with SSc. Whole-chest HRCT, serving as standard of reference, and the reduced HRCT with nine slices allocated according to a basal-apical gradient were obtained. ILD presence, extent (> or <20%) and diagnostic confidence were assessed. The reduced HRCT was independently analysed by two blinded radiologists, who also evaluated image quality. Radiation dose parameters were calculated.
  
  
  RESULTS
  Standard chest HRCT showed ILD in 77/170 patients. With the reduced HRCT, 68/77 cases with ILD were identified (sensitivity 88.3%, both readers). The accuracy (91.8%, reader 1; 94.7%, reader 2), diagnostic confidence (98.8%, reader 1; 95.3%, reader 2) and image quality rates were high. Minimal ILD was correctly quantified in 73.1% (reader 1)/71.2% (reader 2) and extensive ILD in 88% (reader 1)/100% (reader 2). Importantly, the reduced HRCT had a significantly lower radiation dose. The mean dose length product (effective dose) was only 5.66±4.46 mGycm (0.08±0.06 mSv) compared with the standard protocol dose of 149.00±95.90 mGycm (2.09±1.34 mSv).
  
  
  CONCLUSIONS
  The above-described reduced chest HRCT protocol reliably detects even mild SSc-ILD in clinical practice, with the advantage of a much lower radiation dose compared with standard whole-chest HRCT.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenfelder
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Anna
authors.initials: A
authors.lastname: Winklehner
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Thi Dan Linh
authors.initials: TD
authors.lastname: Nguyen
authors.affiliation: Division of Rheumatology, University Hospital Zurich, Zurich, Switzerland Department of Internal Medicine and Rheumatology, Dr. I. Cantacuzino Hospital, Bucharest, Romania.
authors.forename: Rucsandra
authors.initials: R
authors.lastname: Dobrota
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Baumueller
authors.affiliation: Division of Rheumatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Britta
authors.initials: B
authors.lastname: Maurer
authors.affiliation: Division of Rheumatology, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Distler
mesh_terms: D000368:Aged; D015331:Cohort Studies; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D017563:Lung Diseases, Interstitial / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D011829:Radiation Dosage; D012595:Scleroderma, Systemic / Q000150:complications / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity
keywords: Multidisciplinary team-care; Outcomes research; Pulmonary Fibrosis; Systemic Sclerosis