title: 128-slice CT angiography of the aorta without ECG-gating: efficacy of faster gantry rotation time and iterative reconstruction in terms of image quality and radiation dose.
abstract: OBJECTIVE
  To evaluate image quality and radiation dose of non ECG-gated 128-slice CT angiography of the aorta (CTAA) with fast gantry rotation time and iterative reconstruction.
  
  
  METHODS
  Four hundred and eighty patients underwent non ECG-gated CTAA. Qualitative and quantitative image quality assessments were performed. Radiation dose was assessed and compared with the dose of patients who underwent ECG-gated CTAA (n = 126) and the dose of previous CTAA performed with another CT (n = 339).
  
  
  RESULTS
  Image quality (aortic root-ascending portion) was average-to-excellent in more than 94% of cases, without any non-diagnostic scan. For proximal coronaries, image quality was average-to-excellent in more than 50%, with only 21.5% of non-diagnostic cases. Quantitative analysis results were also good. Mean radiation dose for thoracic CTAA was 5.6 mSv versus 20.6 mSv of ECG-gated protocol and 20.6 mSv of 16-slice CTAA scans, with an average dose reduction of 72.8% (p < 0.001). Mean radiation dose for thoracic-abdominal CTAA was 9.7 mSv, versus 20.9 mSv of 16-slice CTAA scans, with an average dose reduction of 53.6% (p < 0.001).
  
  
  CONCLUSIONS
  Non ECG-gated 128-slice CTAA is feasible and able to provide high quality visualization of the entire aorta without significant motion artefacts, together with a considerable dose and contrast media volume reduction.
  
  
  CONCLUSIONS
  • CT image quality of aortic root-ascending aorta is challenging. • Non ECG-gated scans are often limited by pulsatility artefacts. • ECG-gated examinations are usually limited by high radiation doses. • Non ECG-gated 128-slice low dose CTAA provides high quality images. • 128-slice CTAA low dose protocol could frequently replace ECG-gated CTAA.
authors.affiliation: Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, University Hospital "S.Orsola", Via Massarenti 9, Bologna, Italy. vi-rus@fastwebnet.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Russo
authors.affiliation: Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, University Hospital "S.Orsola", Via Massarenti 9, Bologna, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Garattoni
authors.affiliation: Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, University Hospital "S.Orsola", Via Massarenti 9, Bologna, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Buia
authors.affiliation: Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, University Hospital "S.Orsola", Via Massarenti 9, Bologna, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Attinà
authors.affiliation: Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, University Hospital "S.Orsola", Via Massarenti 9, Bologna, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Lovato
authors.affiliation: Cardio-Thoracic-Vascular Department, Cardio-Thoracic Radiology Unit, University Hospital "S.Orsola", Via Massarenti 9, Bologna, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Zompatori
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001027:Aortography / Q000379:methods*; D016477:Artifacts; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods; D004562:Electrocardiography / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012399:Rotation; D014057:Tomography, X-Ray Computed / Q000379:methods*; D055815:Young Adult
chemical_list: D003287:Contrast Media
keywords: Aorta; Image quality; Iterative reconstruction; Multidetector CT; Radiation dosage