1029 Agreement of left ventricular mass in steady state free precession (ssfp) and delayed enhancement (DE) MR images: implications for quantification of fibrosis in congenital and ischemic heart disease

Visualization of fibrosis is important since it aids in diagnosis, treatment and prognosis. MRI is being established as the reference method for detection of fibrosis, myocardial infarction and quantification of left ventricular mass (LVM) both in the clinical setting and in clinical trials. The percentage of infarcted myocardium of the left ventricle is increasingly being used in clinical reports as well as preclinical and clinical trials. Delineation of fibrosis is carried out in delayed enhancement images where normal myocardium is black and fibrosis is white (Figure 1 ). Quantification of total left ventricular mass (LVM) can be carried out by delineating endo- and epicardium in steady state free precession (ssfp) cine images, but also in the delayed enhancement images. However, the DE sequence differ from the ssfp, which makes it possible that the quantification of volumes (e.g. LVM) may differ. It is important that the two different image sequences are comparable for determination of total amount of myocardium in order to express fibrosis as a percentage of total myocardium. This is of specific importance in patients with congenital heart disease because differentiation between myocardium and other structures such as connective tissue, scar, fibrosis and implanted structures may be difficult. To be able to use both balanced sequences and delayed enhancement images for determination of total amount of myocardium would therefore be beneficial.