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.
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
|Speed||Cardiac motion||Respiratory motion||Spatial resolution||Contrast||Signal/Noise|
|Segmented / spiral k-space filling||Incr.|
|Real time imaging||Incr.||X||X||Decr.|
|Target study of coronary axis routes||Incr.|
|Global 3D study of the entire heart||Decr.||Incr.||Incr.|
|Cardiac synchro in mid-diastole||Decr.||X|
|Gradient echo with balanced gradients||Incr.||Incr.|
|Contrast agents with vascular remanence||X|
|Dark blood imaging||X|
Potential clinical applications