title: Feasibility of ultra-low contrast 64-slice computed tomography angiography before transcatheter aortic valve implantation: a real-world experience.
abstract: OBJECTIVE
  To investigate the feasibility, image quality, and clinical implications of an ultra-low-dose contrast injection computed tomography angiography (CTA) protocol in patients scheduled for transcatheter aortic valve implantation (TAVI).
  
  
  RESULTS
  Images obtained with 64-slice CT were retrospectively evaluated in 162 TAVI candidates with a body mass index (BMI) of ≤29 kg/m(2). A multiphasic, low iodine dose and BMI-adapted CM protocol was administered in all patients (BMI <22 kg/m(2): 40 mL; BMI 22-29 kg/m(2): 55 mL). All images were evaluated for image quality, vessel attenuation, and estimated radiation dose. The anatomy, diameters, perimeter, and area of the aortic annulus were assessed. Anatomy and diameters of peripheral vessels were also evaluated. Image quality of the aortic root and ilio-femoral vessels was diagnostic in all patients. Vascular attenuation was >200 HU at any vessel level. The mean diameters of the aortic annulus were 22 ± 3 mm (range: 16-28 mm) × 26 ± 3 mm (range: 20-33 mm); the mean perimeter was 77.0 ± 7.1 mm. After CTA, a total of 137 patients (84.6%) underwent TAVI. Mean estimated radiation dose was 20.2 ± 4.6 mSv.
  
  
  CONCLUSIONS
  With our protocol, we achieved images of the aortic annulus and aorto-iliac anatomy of sufficient quality to allow patient selection and procedural planning for TAVI, with a substantial reduction of the amount of injected CM.
authors.affiliation: Cardiovascular Disease Prevention Centre (CPC), San Raffaele Scientific Institute, Via Olgettina, 60, Milan 20132, Italy spagnolo.pietro@hsr.it.
authors.forename: Pietro
authors.initials: P
authors.lastname: Spagnolo
authors.affiliation: Cardiovascular Disease Prevention Centre (CPC), San Raffaele Scientific Institute, Via Olgettina, 60, Milan 20132, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Giglio
authors.affiliation: School of Medicine, University of Milano-Bicocca, Milan, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Di Marco
authors.affiliation: Interventional Cardiology Unit and Cardiothoracic Department, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Azeem
authors.initials: A
authors.lastname: Latib
authors.affiliation: Cardiovascular Disease Prevention Centre (CPC), San Raffaele Scientific Institute, Via Olgettina, 60, Milan 20132, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Besana
authors.affiliation: Interventional Cardiology Unit and Cardiothoracic Department, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Alaide
authors.initials: A
authors.lastname: Chieffo
authors.affiliation: Interventional Cardiology Unit and Cardiothoracic Department, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Montorfano
authors.affiliation: School of Medicine, University of Milano-Bicocca, Milan, Italy.
authors.forename: Sandro
authors.initials: S
authors.lastname: Sironi
authors.affiliation: Cardiac Surgery Department, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Ottavio
authors.initials: O
authors.lastname: Alfieri
authors.affiliation: Interventional Cardiology Unit and Cardiothoracic Department, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Colombo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000601:surgery; D015992:Body Mass Index; D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D065467:Transcatheter Aortic Valve Replacement
chemical_list: D003287:Contrast Media
keywords: CT angiography; contrast injection; contrast-induced acute kidney injury; transcatheter aortic valve implantation