Abstract 11169: Initial Experience with Five-Dimensional Cardiac-Respiratory Ventricular Function Evaluation Using a Novel Magnetic Resonance Imaging Technique
Introduction: Characterization of the pressure-volume relationship is central to the understanding of a wide range of cardiac conditions, including restrictive/constrictive disease and heart failure with preserved systolic function (HFPSF). Magnetic Resonance Imaging (MRI) is currently the gold standard in assessment of cardiac function, but conventional MRI techniques are unable to quantify volumetric changes under conditions of varying intrathoracic pressures.
Hypothesis: We investigated the hypothesis that a novel five-dimensional (5D) MRI technique (3D volume resolved over the cardiac and respiratory cycles) based on the 3D cones non-Cartesian trajectory is capable of detecting variations in ventricular volumes and ejection fraction caused by respiratory-induced intrathoracic pressure changes during normal free breathing.
Methods: Normal volunteers were imaged at 1.5T to demonstrate the feasibility of the proposed 5D MRI technique. A 3D stack of short-axis images (36x36x8 cm3 field of view, 2.4x2.4x8 mm3 resolution) was acquired using an accelerated 3D cones steady-state free precession sequence during a 4 min 30 sec free-breathing scan to fully sample the cardiac and respiratory cycles. Respiratory bellows and pulse oximeter signals were recorded during the scan for retrospective data reordering. Data was reconstructed in 5D and displayed as volumetric cardiac cines at each resolved respiratory phase. The ejection fraction was calculated for each respiratory phase.
Results: Figure 1 displays representative end-diastolic and end-systolic images at different respiratory phases from a normal volunteer. The measured ventricular volumes and ejection fraction show variation with respect to respiration.
Conclusions: This novel 5D MRI technique can provide 3D volumetric data resolved over both cardiac and respiratory phases and may allow more detailed evaluation of the pressure-volume relationship in a range of cardiac conditions.
- © 2011 by American Heart Association, Inc.