Table 3 Cardiac magnetic resonance imaging protocol
Examinations at baseline and after 12 weeks | |
|---|---|
Infarct size: - Myocardial oedema (area at risk) - Myocardial salvage index - Left ventricular volumes and mass - Left ventricular ejection fraction | |
Technical standards | |
- The salvaged myocardium is defined as area at risk minus final infarct size - The myocardial salvage index (MSI) is defined as area at risk minus final infarct size as a percentage of the area at risk - The area at risk is measured 3 to 5 days after PCI and final myocardial infarct size is measured 12 weeks later - Patients will be examined in supine position with care taken to ensure identical position in the scanner for both exams - All images will be acquired using ECG gating technique - Cine images will be acquired with a steady state free precession sequence according to a systematic protocol - The entire left ventricle is covered with a stack of short axis images - Short-axis T2w-STIR imaging is used for myocardial oedema imaging - 10–15 min after bolus injection of gadolinium contrast medium (0.2 mmol/kg body weight) myocardial DE-CMR will be performed with consecutive short axis slices - All analyses will be conducted according to established standard operating procedures - Calculation of left ventricular volumes and ejection fraction is performed using standard available analysis software - The extent of myocardial oedema and delayed enhancement in each image will be quantified with standard analysis software - Regions of infarct-related area at risk (oedema) and myocardial infarction were identified as hyperintense regions within the T2w-STIR images and DE-CMR images, respectively - The myocardium at-risk region and the infarcted region is delineated automatically with manual adjustment when needed on delayed enhancement imaging - All measurements will be expressed as percentage of the total left ventricular myocardial mass and quantified in grams |