Contrast enhanced MRI and MR coronary angiography (MRCA) as one stop shop in patients with untreated myocardial infarction

Purpose

To define MRI role in patients with myocardial infarction not treated by PCI.

Methods and materials

24 pts (17 males, 7 females) with myocardial infarction (7 anterior, 9 lateral, 8 inferior), untreated by PCI, underwent MRI within three weeks after infarction. MRI was performed on a 1.5 T scanner (GE Signa Excite) with this protocol:

1) Triple-IR FSE sequence short axis for edema;

2) Fiesta sequences on short, horizontal and vertical long axes, for regional and global systolic function;

3) FGR-ET short axis sequence for first pass;

4) IR-FGRE sequence on short, horizontal and vertical long axes, for infarct size.

5) Before delayed imaging, MRCA with breath-hold 3D Fiesta VCATS technique was obtained. MRCA was compared with the gold standard conventional coronary angiography (CA), performed within 24–48 h.

Results

MRCA was scored with a 3 points scale (0 = good, 1 = sufficient, 2 = poor) by 2 blinded readers; 3 exams were excluded as pts could not hold their breath. MRCA showed 11 severe stenoses (>50%) and 9 occlusions, with 1 exam not evaluable for poor quality; CA showed severe stenoses in 14 and 7 occlusions. Collaterals and retrograde filling were present in 2 occlusions at CA; in these 2 cases DE at MRI was ≤50%. DE and FP defects distribution always showed correlation with the diseased vessel. MRCA showed 100% sensitivity, 78.6% specificity, 70% PPV, 100% NPV.

Conclusion

In pts not treated by primary or rescue PCI, MRCA can rule out occlusion and/or significant stenosis; the correlation with segmental distribution of DE is excellent.