title: Dynamic real-time architecture in magnetic resonance coronary angiography--a prospective clinical trial.
abstract: OBJECTIVE
  A dynamic real-time (dRT) architecture has been developed to address limitations in magnetic resonance coronary angiography (MRCA). A prospective clinical trial of 45 patients suspected of coronary artery disease was conducted to determine clinical utility of this integrated real-time system.
  
  
  BACKGROUND
  Clinical implementation of MRCA is not performed routinely today. However, improved anatomic coverage, image quality, and scan flexibility may enhance its clinical utility. A novel real-time architecture addresses these challenges through instantaneous reconfiguration between real-time (RT) and high-resolution (HR) imaging sequences with dynamic selection of the desired element on a custom-designed receiver coil.
  
  
  METHODS
  A total of 45 subjects were recruited consecutively to evaluate scan time, anatomic coverage, image quality, and detection of coronary lesions. Using a modern PC, the dRT switches from RT to gated HR imaging sequence in one repetition time (39 ms). Magnetic resonance imaging (MRI) scanning was performed using a custom-designed coronary coil consisting of two four-inch phase-array circular elements enabled with real-time selection of the desired coil element.
  
  
  RESULTS
  All studies were completed in less than 45 minutes and required a mean of 12 breath holds (16 heartbeats). Of the total number of coronary segments, 91% (357/394) were visualized. Excellent or good image quality was achieved in 86% of the segments. Blinded analysis of the coronary arteries revealed sensitivity of 93% and specificity of 88% in the detection of coronary stenoses.
  
  
  CONCLUSIONS
  The integrated environment of dRT provides a rapid and flexible scan protocol for MRCA while achieving wide anatomical coverage, high image quality, and reliable detection of coronary stenosis in short scan time.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University Medical Center, Stanford, California 94305-5233, USA. pyang@cvmed.stanford.edu
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Yang
authors.forename: Juan M
authors.initials: JM
authors.lastname: Santos
authors.forename: Patricia K
authors.initials: PK
authors.lastname: Nguyen
authors.forename: Greig C
authors.initials: GC
authors.lastname: Scott
authors.forename: Jan
authors.initials: J
authors.lastname: Engvall
authors.forename: Michael V
authors.initials: MV
authors.lastname: McConnell
authors.forename: Graham A
authors.initials: GA
authors.lastname: Wright
authors.forename: Dwight G
authors.initials: DG
authors.lastname: Nishimura
authors.forename: John M
authors.initials: JM
authors.lastname: Pauly
authors.forename: Bob S
authors.initials: BS
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003199:Computer Systems; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000175:diagnosis*; D003331:Coronary Vessels / Q000473:pathology*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D011856:Radiographic Image Enhancement; D012680:Sensitivity and Specificity