title: A clinical combined gadobutrol bolus and slow infusion protocol enabling angiography, inversion recovery whole heart, and late gadolinium enhancement imaging in a single study.
abstract: BACKGROUND
  The use of gadolinium contrast agents in cardiovascular magnetic resonance is well-established and serves to improve both vascular imaging as well as enable late gadolinium enhancement (LGE) imaging for tissue characterization. Currently, gadofosveset trisodium, an intravascular contrast agent, combined with a three-dimensional inversion recovery balanced steady state free precession (3D IR bSSFP) sequence, is commonly used in pediatric cardiac imaging and yields excellent vascular imaging, but cannot be used for late gadolinium enhancement. Gadofosveset use remains limited in clinical practice, and manufacture was recently halted, thus an alternative is needed to allow 3D IR bSSFP and LGE in the same study.
  
  
  METHODS
  Here we propose a protocol to give a bolus of 0.1 mL/kg = 0.1 mmol/kg gadobutrol (GADAVIST/GADOVIST) for time-resolved magnetic resonance angiography (MRA). Subsequently, 0.1 mmol/kg is diluted up to 5 or 7.5 mL with saline and then loaded into intravenous tubing connected to the patient. A 0.5 mL short bolus is infused, then a slow infusion is given at 0.02 or 0.03 mL/s. Image navigated (iNAV) 3D IR bSSFP imaging is initiated 45-60 s after the initiation of the infusion, with a total image acquisition time of ~5 min. If necessary, LGE imaging using phase sensitive inversion recovery reconstruction (PSIR) is performed at 10 min after the infusion is initiated.
  
  
  RESULTS
  We have successfully performed the above protocol with good image quality on 10 patients with both time-resolved MRA and 3D IR bSSFP iNAV imaging. Our initial attempts to use pencil beam respiratory navigation failed due to signal labeling in the liver by the navigator. We have also performed 2D PSIR LGE successfully, with both LGE positive and LGE negative results.
  
  
  CONCLUSIONS
  A bolus of gadobutrol, followed later by a slow infusion, allows time-resolved MRA, 3D IR bSSFP using the iNAV navigation technique, and LGE imaging, all in a single study with a single contrast agent.
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA. Animesh.Tandon@UTSouthwestern.edu.|Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA. Animesh.Tandon@UTSouthwestern.edu.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Dr, Dallas, 75235, Texas, USA. Animesh.Tandon@UTSouthwestern.edu.
authors.forename: Animesh
authors.identifier: http://orcid.org/0000-0001-9769-8801
authors.initials: A
authors.lastname: Tandon
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Dr, Dallas, 75235, Texas, USA.
authors.forename: Lorraine
authors.initials: L
authors.lastname: James
authors.affiliation: Department of Imaging and Biomedical Engineering, King's College London, London, UK.
authors.forename: Markus
authors.initials: M
authors.lastname: Henningsson
authors.affiliation: Department of Imaging and Biomedical Engineering, King's College London, London, UK.|Pontificia Universidad Católica de Chile, Escuela de Ingeniería, Santiago, Chile.
authors.forename: René M
authors.initials: RM
authors.lastname: Botnar
authors.affiliation: Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Dr, Dallas, 75235, Texas, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Potersnak
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA.|Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Dr, Dallas, 75235, Texas, USA.
authors.forename: Gerald F
authors.initials: GF
authors.lastname: Greil
authors.affiliation: Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA.|Department of Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, 75390, Texas, USA.|Pediatric Cardiology, Children's Medical Center Dallas, 1935 Medical District Dr, Dallas, 75235, Texas, USA.
authors.forename: Tarique
authors.initials: T
authors.lastname: Hussain
mesh_terms: D003287:Contrast Media / Q000008:administration & dosage*; D017023:Coronary Angiography / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D018810:Magnetic Resonance Angiography / Q000379:methods*; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D009942:Organometallic Compounds / Q000008:administration & dosage*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; C090600:gadobutrol
keywords: Congenital heart disease; Gadobutrol; Late gadolinium enhancement; Steady state magnetic resonance angiography; Time-resolved magnetic resonance angiography