Dynamic real-time architecture in magnetic resonance coronary angiography--a prospective clinical trial.
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.
Yang
Phillip C
PC
Division of Cardiovascular Medicine, Department of Medicine, Stanford University Medical Center, Stanford, California 94305-5233, USA. pyang@cvmed.stanford.edu
Santos
Juan M
JM
Nguyen
Patricia K
PK
Scott
Greig C
GC
Engvall
Jan
J
McConnell
Michael V
MV
Wright
Graham A
GA
Nishimura
Dwight G
DG
Pauly
John M
JM
Hu
Bob S
BS
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