Respiratory self navigated whole-heart angiography with ultra-small super-paramagnetic iron oxide particles: a feasibility study

Background Self-navigation (SN) in 3D radial segmented MR imaging [1] has been shown to be an efficient and robust method for depiction of coronary luminal anatomy using MRI. This method has largely been used at 1.5T using SSFP readouts to provide the high blood to myocardium contrast required for vessel segmentation and SN. However, bSSFP imaging is often confounded by off-resonance artifacts at higher field strengths and conventional Gadolinium based contrast agents combined with inversion-recovery preparation and gradient-echo readouts often cannot achieve a constant signal throughout the scan. Variable contrast throughout the acquisition can cause deterioration in the SN signal and therefore of the motion correction. Here we investigate the use of an intravascular contrast agent (USPIO) with long half-life as a potential method to improve the performance of the SN approach at 3T.