Anne-Marie Koop

208 low-angle shot (FLASH) method, which obviates the need for an electrocardiogram (ECG) and respiratory gating. The acquisition parameters are displayed in table 1 . Save the images in DICOM format. 4.4. Performing analyses on acquired images 4.4.1. Double click on the software to open the program. 4.4.2. Open images in the CMR postprocessing software by using the import button. 4.4.3. Identify the end-systolic phase (defined as the phase with the visually smallest RV cavity) and the end-diastolic phase (defined as the phase with the visually largest RV cavity). 4.4.4. According to guidelines from the Society for Cardiovascular Magnetic Resonance 49 cardiovascular magnetic resonance (CMR, draw the epicardial contours manually in end-diastole and end-systole from apex to base, by marking several points at the epicardial border of each image. At the last point, double click to complete the epicardial contour. 4.4.5. Do the same for the endocardial contours. ( figure 2 ). The left ventricular and right ventricular EDV, ESV, ED mass, and ES mass are now automatically calculated by the software. NOTE: Mass is defined as myocardial volume times myocardial density (i.e., 1.05). 4.4.6. Depending on the research question and population under study, index these variables for subject size by means of tibia length or body weight, according to previously published formulas 50 . 4.4.7. Calculate the eccentricity index (EI) both in end-diastole and end-systole, by dividing the diameter of the LV cavity parallel to the intraventricular septum (IVS) by the diameter of the LV cavity perpendicular to the IVS, derived from the short axis at midpapillary level. 4.4.8. The software calculates the stroke volume (SV) in mL as SV=EDV-ESV, and ejection fraction (EF, %) as . 4.4.9. Calculate the cardiac output (CO) in ml/min as . The heart rate is measured manually by the pressure pad embedded in the animal bed as described above, because the scanner is not able to register the high frequent heart rate adequately. 4.4.10. Depending on the research question and population under study, index the CO and SV for subject size by means of tibia length or body weight, according to