Coronary MR angiography


Coronary MR angiography is a promising technique for coronary artery imaging in 3D, as it is non-invasive, non-irradiating and does not necessarily require injecting a contrast agent.
 However numerous technical difficulties need to be overcome, and no validated method or sequence exists to date.
 Therefore we will focus on the constraints involved in coronary MR angiography techniques, and the solutions currently available.

 

Technical challenges

The coronary vascular system is small in caliber and sinuous, relatively spread out in space, with the presence of pericardial fat on contact. Coronary MR angiography thus has to establish a compromise between acquisition time, spatial resolution, ratio of contrast versus noise and the correction of cardiac and respiratory motion.

 

State of the art
 SpeedCardiac motionRespiratory motionSpatial resolutionContrastSignal/Noise
High field     Incr.
Parallel acquisitionIncr.     
Segmented/spiral k-space fillingIncr.     
Real time imagingIncr. x xDecr.  
Target study of coronary axis routesIncr.     
Global 3D study of the entire heartDecr.  Incr. Incr.
Cardiac synchro in mid-diastoleDecr. x    
Breath-hold   x   
Echo navigatorDecr.  x   
Gradient echo with balanced gradientsIncr.   Incr. 
Contrast agents with vascular remanence     x 
Dark blood imaging     x 
T2 pre-impulsion    Incr. 
Fat Saturation     ncr. 

 

Potential clinical applications
  • Coronary stenosis
  • Coronary bypass
  • Imaging of plaque and the artery walls