title: Value of ultra-low-dose chest CT with iterative reconstruction for selected emergency room patients with acute dyspnea.
abstract: OBJECTIVE
  To compare the diagnostic confidence between low-dose computed-tomography (LDCT) and ultra-low-dose CT (ULDCT) of the chest on a single source CT system (SSCT) for patients with acute dyspnoea.
  
  
  METHODS
  One hundred thirty-three consecutive dyspnoeic patients referred from the emergency room (ER) were selected to undergo two sequential non-enhanced chest CT acquisitions: LDCT first acquisition (100kVp and 60mAs), followed by ULDCT (100kVp±20 and 10mAs). Images were reconstructed with sinogram affirmed reconstruction (SAFIRE). Objective and subjective image quality assessments were made. Two radiologists evaluated subjective image quality and the level of diagnostic confidence as certain or uncertain.
  
  
  RESULTS
  The mean effective doses (ED) were 1.164±0.403 and 0.182±0.028mSv for LDCT and ULDCT, respectively. Objective image quality improved significantly on lung images of ULDCT compared with LDCT (p<0.05). Subjective image quality was rated excellent/good in 90% of patients with BMI=25kg/m(2) for ULDCT. The level of diagnostic confidence was "certain" in all cases for both radiologists with excellent inter-observer agreement (k=1).
  
  
  CONCLUSIONS
  Chest ULDCT with SAFIRE on a SSCT allows a high level diagnostic confidence for the evaluation of selected acute dyspnoeic patients.
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France; Department of Emergency Radiology, Umberto I Hospital, Sapienza University, Rome, Italy. Electronic address: francesco.macri@chu-nimes.fr.
authors: Francesco
authors: F
authors: Macri
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France.
authors: Joel
authors: J
authors: Greffier
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France.
authors: Fabricio
authors: F
authors: Pereira
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France.
authors: Alina Chica
authors: AC
authors: Rosa
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France.
authors: Elina
authors: E
authors: Khasanova
authors: Department of Emergency care and Traumatology, Nîmes University Hospital, Nîmes, France.
authors: Pierre-Geraut
authors: PG
authors: Claret
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France.
authors: Ahmed
authors: A
authors: Larbi
authors: Department of Emergency Radiology, Umberto I Hospital, Sapienza University, Rome, Italy.
authors: Gianfranco
authors: G
authors: Gualdi
authors: Department of Radiology, Nîmes University Hospital, Medical Imaging Group Nîmes, EA 2415, Nîmes, France.
authors: Jean Paul
authors: JP
authors: Beregi
mesh_terms: D000368:Aged; D016477:Artifacts; D015992:Body Mass Index; D004417:Dyspnea / Q000000981:diagnostic imaging* / Q000473:pathology; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012372:ROC Curve; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000009:adverse effects / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Chest computed tomography; Emergency room; Iterative; Radiation protection; Reconstruction; Ultra-low-dose