Cardiac MRI Protocol for Framingham Heart Study

The Framingham Heart Study cardiac MRI protocol has been reported elsewhere.^{2 (link),10 (link),11 (link)} Briefly, supine imaging was performed on a Philips 1.5T scanner with a 5-element commercial cardiac array coil. End-expiratory breath-hold, ECG-gated cine steady state free precession images were acquired in 2-chamber, 4-chamber, and contiguous short axis orientations (temporal resolution, 39ms; repetition time, R-R interval; echo time, 9ms; flip angle, 30°; field of view, 400mm; matrix size, 208x256; slice thickness, 10mm; gap, 0mm). Analyses were performed by an experienced reviewer blinded to clinical information using a clinical workstation (EasyVision 5.1, Philips Medical Systems). End-diastolic volume (EDV) was determined as the minimal cross-sectional area of a midventricular slice. EDV and end-systolic volume (ESV) were computed by summation-of-disks method with cardiac output (L/min) calculated as (EDV-ESV) x heart rate. Cardiac output was divided by body surface area to calculate cardiac index (L/min/m²). Inter-rater reliability correlation coefficient for EDV=0.95 and for ESV=0.92. Intra-observer coefficient of variation for EDV=2.6% and for ESV=3.5%.^{12 (link)} Inter-observer coefficient of variation for EDV=3.5% and ESV=4.8%.^{12 (link)}