Purpose
The aim of the study was to evaluate the feasibility of hybrid magnetic resonance/positron emission tomography (MR-PET) imaging of the heart (CMR-PET) in patients with acute myocardial infarction with an integrated simultaneous MR and PET system and to discuss its potential clinical impact.
Methods and Materials
Eight patients with confirmed acute ST segment elevationmyocardial infarction underwent CMR-PET with 18F-fluorodeoxyglucose within 2-7 days after interventional revascularization.
For comparison of infarct identification and characterization the left ventricle was mapped to the 17-segment model recommended by the American Heart Association.Tracer accumulation in each myocardial segment was compared to regional wall motion abnormalities and to signal intensity in late gadolinium-enhanced (LGE) images.
The size of the infarct zone was measured with freehandedly drawn regions on the LGE MR images and PET images and was expressed...
Results
Cardiac MR-PET was successfully performed in all patients.
Absolute parallelized scan time was 63±3 minutes.
Categorical inter-method agreement between PET and LGE imaging over all patients and segments was κ=0.79 and κ=0.70 between PET and cine imaging.
Forty-four of 136 segments (32%) were rated as infarcted in PET images compared to 40 segments (29%) in LGE images and 31 segments (23%) in cine images.
On average 32% of the entire left ventricular myocardium were classified as infarcted in PET images and 28% in LGE images...
Conclusion
CMR-PET in patients with acute myocardial infarction is feasible on an integrated whole-body MR-PET scanner at 3 Tesla field strength.
The study demonstrates a close match between PET and MRI regarding myocardial viability and infarct quantification.
Further study will show,
if cardiac MR-PET adds complementary information and improves clinical risk stratification in patients with ischemic cardiac disease.
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