title: Part 1 - Coronary angiography with gadofosveset trisodium: a prospective feasibility study evaluating injection techniques for steady-state imaging.
abstract: BACKGROUND
  The purpose of this study was to define an optimal injection protocol for 5-10 min duration navigator-based coronary MR angiography using an intravascular gadolinium-based contrast agent (GBCA), which is better suited for steady-state coronary MR angiography than conventional GBCAs.
  
  
  METHODS
  Using projections from pharmacokinetic models of the intravascular concentration of gadofosveset, a dual-injection protocol was formulated and tested on 14 healthy human subjects. Modified Look-Locker inversion recovery (MOLLI) sequences were used for T1 mapping at 3 Tesla to evaluate the concentration of tracer in the aorta over the scanning interval.
  
  
  RESULTS
  Pharmacokinetic models for a bolus plus slow infusion technique at a 5, 10, and 15 min steady state intravascular concentration was compared to single bolus curves. The 70 %/30 % bolus/slow infusion technique resulted in the highest intravascular concentration over a 5 min scan duration. Similarly, the 60 %/40 % bolus/slow infusion technique was projected to be ideal for image acquisition duration of 5-10 min. These models were confirmed with T1 maps on normal volunteers. Arterial-venous mixing of contrast was achieved within 90 s of the beginning of the bolus.
  
  
  CONCLUSIONS
  Gadofosveset injection is optimized for the lowest intravascular T1 time for 5-10 min duration MR angiography by bolus injection of 60-70 % of the total dose followed by slow infusion of the remainder of the total dose. This protocol achieves rapid and prolonged steady state intravascular concentrations of the GBCA that may be useful for prolonged image acquisition, such as required for navigator-based coronary MR angiography at 3 Tesla.
  
  
  BACKGROUND
  ClinicalTrials.gov identifier: NCT01130545 NCT01130545 , registered as of May 25, 2010.
authors.affiliation: Radiology and Imaging Sciences - National Institutes of Health Clinical Center, Bethesda, MD, USA. mark.ahlman@nih.gov.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Ahlman
authors.affiliation: Radiology and Imaging Sciences - National Institutes of Health Clinical Center, Bethesda, MD, USA. fobs89@gmail.com.
authors.forename: Fabio S
authors.initials: FS
authors.lastname: Raman
authors.affiliation: Department of Pharmacotherapy, University of North Texas, Fort Worth, TX, USA. scott.penzak@unthsc.edu.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Penzak
authors.affiliation: Bioengineering, Cedars-Sinai Medical Center, Los Angeles, CA, USA. pangjianing@gmail.com.
authors.forename: Jianing
authors.initials: J
authors.lastname: Pang
authors.affiliation: Bioengineering, Cedars-Sinai Medical Center, Los Angeles, CA, USA. zhaoyang.fan@cshs.org.
authors.forename: Zhaoyang
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Radiology and Imaging Sciences - National Institutes of Health Clinical Center, Bethesda, MD, USA. songtao.liu@gmail.com.
authors.forename: Songtao
authors.initials: S
authors.lastname: Liu
authors.affiliation: Radiology and Imaging Sciences - National Institutes of Health Clinical Center, Bethesda, MD, USA. gaind@cc.nih.gov.
authors.forename: Neville
authors.initials: N
authors.lastname: Gai
authors.affiliation: Bioengineering, Cedars-Sinai Medical Center, Los Angeles, CA, USA. debiao.li@cshs.org.
authors.forename: Debiao
authors.initials: D
authors.lastname: Li
authors.affiliation: Radiology and Imaging Sciences - National Institutes of Health Clinical Center, Bethesda, MD, USA. bluemked@cc.nih.gov.
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage* / Q000493:pharmacokinetics; D017023:Coronary Angiography / Q000379:methods*; D003331:Coronary Vessels / Q000473:pathology*; D004334:Drug Administration Schedule; D005240:Feasibility Studies; D005260:Female; D005682:Gadolinium / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D064368:Healthy Volunteers; D006801:Humans; D007263:Infusions, Parenteral; D007267:Injections; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008954:Models, Biological; D009942:Organometallic Compounds / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D011237:Predictive Value of Tests; D011446:Prospective Studies
chemical_list: D003287:Contrast Media; D009942:Organometallic Compounds; D005682:Gadolinium; C109932:gadofosveset trisodium