title: Three-dimensional contrast-enhanced steady-state free precession for improved catheter-directed coronary magnetic resonance angiography.
abstract: OBJECTIVE
  To demonstrate the feasibility of three-dimensional thick-partition, contrast-enhanced, catheter-directed coronary artery magnetic resonance angiography (MRA) and test the hypothesis that three-dimensional imaging improves coronary artery background contrast-to-noise ratio (CNR) compared to two-dimensional imaging.
  
  
  METHODS
  Catheters were advanced into the coronary arteries of swine (N = 6) under MR guidance. Three-dimensional coronary MRA was performed after intracoronary injection of a small dose of contrast media using magnetization-prepared steady-state free precession (SSFP) with two thick partitions. For comparison, two magnetization-prepared two-dimensional SSFP scans were also performed, one with no signal averaging and one with two signal averages. All sequences had the same coverage and in-plane spatial resolution.
  
  
  RESULTS
  The coronary artery was successfully catheterized in all (6/6) animals. CNR for three-dimensional imaging was 11.1 +/- 1.2 for proximal arterial segments and 4.3 +/- 0.4 for distal segments. Without averaging, two-dimensional imaging CNRs for proximal and distal segments were 5.0 +/- 0.7 and 1.2 +/- 0.2, respectively. With averaging, two-dimensional imaging CNRs for proximal and distal segments were 9.4 +/- 1.5 and 2.9 +/- 0.4, respectively. Three-dimensional imaging showed a statistically significant increase in CNR over all two-dimensional imaging for both proximal and distal segments (P < 0.05).
  
  
  CONCLUSIONS
  Three-dimensional thick-partition, contrast-enhanced, catheter-directed coronary MRA is feasible and improves CNR over two-dimensional projection imaging.
authors.affiliation: Department of Radiology, Northwestern University, Chicago, Illinois, USA.
authors.forename: Jordin D
authors.initials: JD
authors.lastname: Green
authors.forename: Reed A
authors.initials: RA
authors.lastname: Omary
authors.forename: Brian E
authors.initials: BE
authors.lastname: Schirf
authors.forename: Richard
authors.initials: R
authors.lastname: Tang
authors.forename: James C
authors.initials: JC
authors.lastname: Carr
authors.forename: Debiao
authors.initials: D
authors.lastname: Li
mesh_terms: D000818:Animals; D002404:Catheterization; D003287:Contrast Media; D017023:Coronary Angiography / Q000379:methods*; D005240:Feasibility Studies; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D013552:Swine
chemical_list: D003287:Contrast Media